Insects

17 pages, 37724 KB

Open AccessEditor’s ChoiceArticle

Multi-Condition Cultivation Reveals the Host Plant-Dependent Gut Bacteria Diversity in Tomato Leafminer (Tuta absoluta) Larvae

by Xiaoyu Fang, Ruoyi Wen, Liyan Yang, Jianyang Guo, Wenjun Shen, Nianwan Yang, Fanghao Wan, Zhichuang Lü and Wanxue Liu

Insects 2026, 17(1), 81; https://doi.org/10.3390/insects17010081 - 10 Jan 2026

Viewed by 1551

Abstract

Tomato leafminer (Tuta absoluta) significantly affects tomato (Solanum lycopersicum) and eggplant (Solanum melongena) crops worldwide, with its feeding patterns being closely associated with its gut microbiota. We aimed to compare the cultivable gut bacteria of T. absoluta [...] Read more.

Tomato leafminer (Tuta absoluta) significantly affects tomato (Solanum lycopersicum) and eggplant (Solanum melongena) crops worldwide, with its feeding patterns being closely associated with its gut microbiota. We aimed to compare the cultivable gut bacteria of T. absoluta larvae fed on tomato and eggplant to investigate their role in host adaptation. Gut bacteria were cultivated on Luria–Bertani broth, nutrient agar, and Brain Heart Infusion media under different temperature conditions, followed by morphology- and 16S rRNA-based identification. Notably, both feeding groups revealed distinct gut bacterial community structures. Tomato-fed larvae harbored bacteria spanning eight species, five genera, four families, and two phyla. In contrast, eggplant-fed larvae exhibited greater microbial diversity, encompassing 15 species, 10 genera, 9 families, and 3 phyla, including unique genera such as Pseudomonas and Pectobacterium, which was attributed to the host plant contribution. Enterococcus mundtii was the most dominant bacterium, and species such as Bacillus wiedmannii and Micrococcus luteus were most thermotolerant. Overall, these findings highlight the importance of multi-condition culture approaches for thoroughly characterizing insect gut microbiota and underscore the role of host plants in pest adaptability by modulating gut microbial communities, providing new insights for developing sustainable control strategies utilizing “plant–insect–microorganism” interactions. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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20 pages, 774 KB

Open AccessEditor’s ChoiceReview

Sublethal Effects of Neonicotinoids: How Physiological and Behavioral Disruptions in Non-Target Insects Threaten Biodiversity and Ecosystem Services

by Sarah K. Spence, Shorooq A. M. Alharbi, Afure Ejomah, Feizollah A. Maleki, Michael S. Wolfin and Mônica F. Kersch-Becker

Insects 2026, 17(1), 26; https://doi.org/10.3390/insects17010026 - 24 Dec 2025

Cited by 8 | Viewed by 3155

Abstract

Neonicotinoid insecticides were initially hailed as safer alternatives to organochlorine and organophosphate pesticides due to their perceived lower toxicity to non-target organisms. However, it has been recently discovered that sublethal exposure to neonicotinoids negatively affects beneficial arthropods that are essential for a functional [...] Read more.

Neonicotinoid insecticides were initially hailed as safer alternatives to organochlorine and organophosphate pesticides due to their perceived lower toxicity to non-target organisms. However, it has been recently discovered that sublethal exposure to neonicotinoids negatively affects beneficial arthropods that are essential for a functional ecosystem. These beneficial arthropods include pollinators, biological control agents, and decomposers. This review synthesizes current research on the physiological, behavioral, and reproductive consequences of neonicotinoids on non-target arthropods and their broader ecological impact. The chemical and physical properties of neonicotinoids raise concerns about long-term ecological consequences of neonicotinoid use because these chemicals are persistent in plants and soil, which contributes to prolonged exposure risks for organisms. Sublethal doses of neonicotinoids can disrupt the ecological services provided by these organisms by impairing essential biological processes including motor function, odor detection, development, and reproduction in insects, while also altering behavior such as foraging, mating, and nesting. Furthermore, neonicotinoid exposure can alter community structure, disrupting trophic interactions and food web stability. Recognizing the sublethal impacts of neonicotinoids is critical for the development of more sustainable pest management strategies. It is imperative that future research investigates the underlying mechanisms of sublethal toxicity and identifies safer, more effective approaches to neonicotinoid-based pest control to mitigate adverse ecological effects. Incorporating this knowledge into future environmental risk assessments will be essential for protecting biodiversity and maintaining ecosystem functionality. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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16 pages, 4019 KB

Open AccessEditor’s ChoiceArticle

Diel Versus Seasonal Butterfly Community Partitioning in a Hyperdiverse Tropical Rainforest

by Sebastián Mena, Janeth Rentería and María F. Checa

Insects 2025, 16(12), 1247; https://doi.org/10.3390/insects16121247 - 10 Dec 2025

Cited by 3 | Viewed by 1184

Abstract

Ecological theory suggests that interspecific interactions and environmental heterogeneity promote temporal niche partitioning, whereby species segregate their activity along diel and seasonal axes. For ectotherms, temperature is a critical niche dimension because heat availability regulates activity and phenology. Here, we used data from [...] Read more.

Ecological theory suggests that interspecific interactions and environmental heterogeneity promote temporal niche partitioning, whereby species segregate their activity along diel and seasonal axes. For ectotherms, temperature is a critical niche dimension because heat availability regulates activity and phenology. Here, we used data from a hyperdiverse rainforest in the Ecuadorian Amazon to compare community dynamics across two temporal scales and to test their relationship with temperature fluctuations. Butterflies were periodically sampled using Pollard walks in a permanent plot over eight field campaigns spanning two years. We compared environmental temperature fluctuations, diversity metrics, and niche-overlap estimates of community assemblages at both diel and seasonal scales. We recorded 1003 individuals representing 222 species. Temperature differences among seasons were comparable to those observed across times of day. Consistently, our analyses revealed distinct community assemblages across both diel and seasonal scales. Furthermore, butterfly activity tended to increase during warmer hours and in warmer seasons, yet overlap in activity within these timeframes was low at both the species and subfamily levels. These results highlight the contribution of both abiotic drivers and biotic interactions in structuring butterfly temporal abundance. More broadly, our study underscores the importance of explicitly considering temporal dimensions when examining tropical biodiversity. Full article

(This article belongs to the Special Issue Ecology, Diversity and Conservation of Butterflies)

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13 pages, 2337 KB

Open AccessEditor’s ChoiceArticle

Beyond Species Averages: Intraspecific Trait Variation Reveals Functional Convergence Under Invasion

by Zhixing Lu, Xinyu Wang, Xiang Zhang and Youqing Chen

Insects 2025, 16(11), 1094; https://doi.org/10.3390/insects16111094 - 24 Oct 2025

Viewed by 2107

Abstract

Biological invasions provide a unique window into community assembly. While classic theory predicts that native species must differentiate their niches to coexist with an invader, the actual outcomes under intense pressure are complex. Our study examines community reassembly under extreme pressure from the [...] Read more.

Biological invasions provide a unique window into community assembly. While classic theory predicts that native species must differentiate their niches to coexist with an invader, the actual outcomes under intense pressure are complex. Our study examines community reassembly under extreme pressure from the invasive ant Solenopsis invicta. We found that while native species do differentiate themselves from the invader, the overwhelming competition constrains this process, forcing survivors into a narrow, shared functional space. This constrained niche differentiation produces a pattern of community-level functional convergence, a process where functionally dissimilar communities become more similar under intense environmental filtering, as survivors are forced into a narrow, shared niche space. The capacity for these rapid, adaptive niche shifts is rooted in intraspecific trait variation (ITV). We also identified a dynamic feedback loop through density-dependent phenotypic plasticity in the invader. By showing how the foundational process of niche differentiation leads to a convergent outcome under extreme pressure, our work clarifies the rules of community assembly in an increasingly invaded world. Full article

(This article belongs to the Section Insect Ecology, Diversity and Conservation)

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15 pages, 2058 KB

Open AccessEditor’s ChoiceArticle

Stomoxys Species Richness and Apparent Densities at Different Land-Use Setups in North-Eastern KwaZulu-Natal Province, South Africa

by Percy Moyaba, Serero Abiot Modise, Johan Esterhuizen, Keisuke Suganuma, Noboru Inoue, Oriel Thekisoe and Moeti Oriel Taioe

Insects 2025, 16(10), 1049; https://doi.org/10.3390/insects16101049 - 15 Oct 2025

Cited by 1 | Viewed by 1506

Abstract

Stomoxys is a genus of blood-sucking dipteran flies from the family Muscidae with approximately 18 species reported globally. This study sought to identify and determine the apparent densities (ADs) and species richness of Stomoxys species occurring in three land-use setups, namely communal farming [...] Read more.

Stomoxys is a genus of blood-sucking dipteran flies from the family Muscidae with approximately 18 species reported globally. This study sought to identify and determine the apparent densities (ADs) and species richness of Stomoxys species occurring in three land-use setups, namely communal farming areas, commercial farms, and private game farms in the north-eastern part of KwaZulu-Natal Province (KZN), South Africa. Thirty-four H-traps were set up across 10 different localities over 30 days of sampling. A total of 1306 Stomoxys flies with an average of 1.28 flies/trap/day were captured, and six Stomoxys species were identified. S. n. niger was the most abundant species (82.3%), followed by S. calcitrans (13.1%), S. taeniatus (1.9%), S. n. bilineatus (0.84%), S. sitiens (1.1%), and S. boueti (0.7%) was the least collected. This study highlights the need to explore this genus further as it demonstrates that more than one species exists in north-eastern KZN. Furthermore, these flies co-exist with tsetse flies (Glossina spp.), meaning that vector control measures should incorporate all potential vectors of animal trypanosomosis and other vector-borne diseases that occur in the area. Full article

(This article belongs to the Section Medical and Livestock Entomology)

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13 pages, 954 KB

Open AccessEditor’s ChoiceArticle

The Molecular Drivers of Honey Robbing in Apis mellifera L.: Morphological Divergence and Oxidative-Immune Regulation Mechanisms Based on Proteomic Analysis

by Xinyu Wang, Xijie Li, Zhanfeng Yan, Mengjuan Hao, Xiao Cui, Zhenxing Liu, Jun Guo and Yazhou Zhao

Insects 2025, 16(9), 987; https://doi.org/10.3390/insects16090987 - 22 Sep 2025

Cited by 2 | Viewed by 1409

Abstract

Honey robbing, as an extreme adaptive response of honey bee colonies to resource scarcity, poses devastating threats to apiaries, yet the underlying molecular mechanisms remain poorly understood. We compared morphological traits and survival rates between robber bees and normal foragers and conducted proteomic [...] Read more.

Honey robbing, as an extreme adaptive response of honey bee colonies to resource scarcity, poses devastating threats to apiaries, yet the underlying molecular mechanisms remain poorly understood. We compared morphological traits and survival rates between robber bees and normal foragers and conducted proteomic sequencing of bee head samples. The results demonstrated that robber bees exhibited darker tergite coloration and significantly shortened lifespan. Proteomic analysis revealed that the darker coloration was primarily attributed to enhanced cuticular melanin deposition mediated by upregulated laccase-5, while the shortened lifespan mainly resulted from oxidative stress and immune suppression: the downregulation of heat shock protein 75 kDa and glutathione transferase weakened antioxidant capacity, and despite compensatory upregulation of the cytochrome P450 enzyme system, flavin-containing monooxygenases and other enzymes, oxidative damage continued to accumulate. Concurrently, downregulation of Defense protein 3 and C-type lectin 5 caused immune deficiency in robber bees. The results also showed metabolic and protein synthesis reprogramming in robber bees, specifically manifested by upregulated key enzymes in nicotinate and nicotinamide metabolism, the pentose phosphate pathway, and nucleotide metabolism, along with activation of protein synthesis-transport-export systems. We found that robber bees employ a “metabolic-synthetic co-enhancement” physiological strategy to boost short-term foraging efficiency, but this strategy simultaneously induces oxidative damage and immune suppression, ultimately shortening their lifespan. This study provides the first proteomic evidence revealing the physiological trade-offs underlying this behavior at the molecular level, offering novel insights into the physiological costs of behavioral adaptation in animals. Full article

(This article belongs to the Section Social Insects and Apiculture)

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13 pages, 7293 KB

Open AccessEditor’s ChoiceArticle

Distribution of Larval Habitats and Efficiency of Various Trap Settings to Monitor Sympatric Aedes albopictus and Aedes aegypti in La Reunion

by Caroline Vitry, Ronan Brouazin, Anthony Herbin, Mathieu Whiteside, Cécile Brengues, Thierry Baldet, Renaud Lancelot and Jérémy Bouyer

Insects 2025, 16(9), 932; https://doi.org/10.3390/insects16090932 - 4 Sep 2025

Viewed by 1779

Abstract

To prepare for a boosted sterile insect technique (SIT) field trial in Saint-Joseph, Reunion island, we compared the attractiveness of two adult mosquito traps for Aedes albopictus and Aedes aegypti. In addition, we explored the co-occurrence of these species in their usual [...] Read more.

To prepare for a boosted sterile insect technique (SIT) field trial in Saint-Joseph, Reunion island, we compared the attractiveness of two adult mosquito traps for Aedes albopictus and Aedes aegypti. In addition, we explored the co-occurrence of these species in their usual larval habitats. Two traps were compared with two conditions each using a Latin square design: BG Sentinel trap baited with carbon dioxide (CO₂) with/without addition of BG Lure and ovi-sticky trap with/without hay. The ovi-sticky traps proved ineffective. For both Aedes species, CO₂-baited traps were equally effective at catching females when baited with the lure or not. In contrast, they were more attractive to males than for females with the lure. Aedes aegypti larvae were found in four of six vacoas (Pandanus utilis), and one of four anthropogenic breeding sites. In vacoas, the densities of Aedes albopictus and Aedes aegypti larvae were negatively correlated, whereas the correlation was positive between chironomids and Aedes aegypti. The abundance of adults and larvae varied according to weather conditions. Finally, CO₂-baited traps were used without lure for the entomological monitoring to assess the effectiveness of the area-wide boosted SIT intervention to reduce costs and logistics. Full article

(This article belongs to the Special Issue Biology, Ecology and Management of Mosquitoes Affecting Humans and Animals—2nd Edition)

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11 pages, 3121 KB

Open AccessEditor’s ChoiceArticle

Apoptosis and Relevant Genes Are Engaged in the Response of Apis mellifera Larvae to Ascosphaera apis Invasion

by Tianze Zhang, Jingxian Li, Jiarun Yang, Xiaoxue Fan, Shiyu Mi, Xi Guo, Mengyuan Dai, Xihan Luo, Peiyuan Zou, Qingwei Tan, Dafu Chen, Jianfeng Qiu and Rui Guo

Insects 2025, 16(9), 925; https://doi.org/10.3390/insects16090925 - 2 Sep 2025

Cited by 3 | Viewed by 1718

Abstract

Apoptosis is a genetically controlled process vital for homeostasis. This study examined the apoptotic response in the gut of Apis mellifera (A. mellifera) larvae to infection by Ascosphaera apis (A. apis) and its impact on host resistance and pathogen [...] Read more.

Apoptosis is a genetically controlled process vital for homeostasis. This study examined the apoptotic response in the gut of Apis mellifera (A. mellifera) larvae to infection by Ascosphaera apis (A. apis) and its impact on host resistance and pathogen virulence. Here, Worker larvae of A. mellifera were inoculated with purified A. apis spores. We then quantified the expression of key apoptosis-related genes (AmCaspase-3, AmBax, and AmBcl-2) in the host gut and detected apoptotic cells via TUNEL assay. To functionally assess the role of apoptosis, larvae were treated with either the apoptosis inhibitor Z-VAD-FMK or the activator PAC-1, after which host survival, expression of apoptosis-associated genes, and the fungal virulence factor gene Ste11-like were analyzed. Our results showed that infection with A. apis significantly upregulated the expression of AmCaspase-3 and AmBax (p < 0.05) at 1–3 days post-inoculation (dpi), while the expression of AmBcl-2 was significantly reduced at 1 and 3 dpi (p < 0.05). Consistent with this, TUNEL assays revealed a markedly stronger green fluorescence signal in the guts of inoculated larvae at 3 dpi compared to uninfected controls, with clear co-localization of TUNEL and nuclear signals, confirming increased apoptosis. Pharmacological inhibition of apoptosis significantly enhanced the survival rate of A. apis-infected larvae, whereas apoptosis activation decreased larval survival. Accordingly, inhibiting apoptosis significantly suppressed the expression of AmCaspase-3 and AmBax (p < 0.001) and upregulated AmBcl-2 (p < 0.001). Conversely, apoptosis activation upregulated AmCaspase-3 (p > 0.05) and AmBax (p < 0.001), while significantly down-regulating AmBcl-2. Furthermore, apoptosis inhibition significantly down-regulated the fungal virulence gene Ste11-like, while its activation had the opposite effect. In summary, A. apis infection induces apoptosis in the larval gut by activating AmCaspase-3 and AmBax and suppressing AmBcl-2. Inhibiting this apoptotic response enhanced host survival by modulating the expression of host apoptosis-related genes and the fungal Ste11-like virulence factor. These findings provide new insights into the host response to A. apis and suggest a potential strategy for controlling chalkbrood disease. Full article

(This article belongs to the Section Social Insects and Apiculture)

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22 pages, 8507 KB

Open AccessEditor’s ChoiceArticle

Ultrastructural Morphology and Descriptive Analysis of Cuticular Sensilla in Adult Tomicus pilifer (Coleoptera: Curculionidae)

by Longzheng Wang, Qi Wang, Yanan Luo and Shanchun Yan

Insects 2025, 16(9), 890; https://doi.org/10.3390/insects16090890 - 26 Aug 2025

Cited by 2 | Viewed by 1506

Abstract

Tomicus pilifer is a major pest that threatens Pinus koraiensis forests in the northeast region of China. In this study, we employed scanning electron microscopy (SEM) to observe the sensilla on the antennae, mouthparts, and legs of both male and female T. pilifer [...] Read more.

Tomicus pilifer is a major pest that threatens Pinus koraiensis forests in the northeast region of China. In this study, we employed scanning electron microscopy (SEM) to observe the sensilla on the antennae, mouthparts, and legs of both male and female T. pilifer adults, analyzing the differences in sensillum types, external morphology, and quantities between sexes. The results revealed six types of sensilla on the antennae of both males and females, including sensilla trichoidea, sensilla zigzag, sensilla coeloconica, sensilla chaetica, Böhm bristles, and sensilla basiconica. Among these, sensilla basiconica was the most abundant, with four subtypes identified, and sensilla basiconica III was observed only on the male antennae, indicating sexual dimorphism in sensillum types. The mouthparts exhibited the greatest diversity in sensilla, with seven types identified: sensilla basiconica, sensilla twig basiconica, sensilla coeloconica, sensilla trichoidea, sensilla chaetica, sensilla zigzag, and sensilla digitiformia. Of these, sensilla basiconica and sensilla twig basiconica, responsible for olfactory or gustatory functions, were concentrated at the distal ends of the maxillary palps and labial palps. On the legs, sensilla trichoidea, sensilla zigzag, and sensilla chaetica were distributed on all segments. The findings of this study provide a scientific basis for further research into the olfactory and feeding behaviors, as well as electrophysiological studies, of T. pilifer. Full article

(This article belongs to the Collection Insect Senses: From Perception to Cognition)

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16 pages, 1018 KB

Open AccessEditor’s ChoiceArticle

Honey Bee Foraging Decisions Are Shaped by Floral Trait Distinctiveness and Perception of Gains or Losses

by Juan C. Hernández, Jair E. García, Harrington Wells and Marisol Amaya-Márquez

Insects 2025, 16(9), 884; https://doi.org/10.3390/insects16090884 - 25 Aug 2025

Cited by 5 | Viewed by 2687

Abstract

The floral choices of honey bees (Apis mellifera) were studied using artificial flower patches to understand how foragers manage changing floral landscapes. Bees were observed under conditions where reward quality changed over time in blue and white flowers. We evaluated initial [...] Read more.

The floral choices of honey bees (Apis mellifera) were studied using artificial flower patches to understand how foragers manage changing floral landscapes. Bees were observed under conditions where reward quality changed over time in blue and white flowers. We evaluated initial learning and reversal learning, varying the magnitude of reward quality-difference and color distinctness in the honey bee’s color vision space (being either similar or more distinct). Flower color fidelity was higher when flower colors were more distinct, but it also made it more difficult for bees to abandon the flower color in the reversal learning phase. Smaller differences in reward quality reduced flower color fidelity and promoted reversal learning. When reward difference between flower colors was created (initial learning), a decrease in one of the flower color rewards elicited a stronger behavioral response from foragers than an increase in reward. Our work highlights that bees used and integrated information from different axes of information: distinctiveness of color cues, magnitude of reward difference, and directionality (being stronger for losses than gains). Thus, flower distinctiveness, opportunity cost, and loss aversion drive honey bee foraging decisions. Higher accuracy at initial learning has stronger costs in behavioral adaptations at changing floral landscapes. Full article

(This article belongs to the Special Issue Bee Conservation: Behavior, Health and Pollination Ecology)

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12 pages, 732 KB

Open AccessEditor’s ChoiceArticle

Influence of Phase Change on Parthenogenesis in the Migratory Locust: A Behavioral Analysis

by Rongjing Li, Xuelei Wei and Liwei Zhang

Insects 2025, 16(9), 878; https://doi.org/10.3390/insects16090878 - 23 Aug 2025

Viewed by 1710

Abstract

The migratory locust (Locusta migratoria), is a destructive pest in agriculture and ecological conservation, characterized by its unique phase polyphenism (phase change). Parthenogenesis, defined as oviparous reproduction without fertilization, has been studied less extensively than fertilized reproduction, with particularly scarce research [...] Read more.

The migratory locust (Locusta migratoria), is a destructive pest in agriculture and ecological conservation, characterized by its unique phase polyphenism (phase change). Parthenogenesis, defined as oviparous reproduction without fertilization, has been studied less extensively than fertilized reproduction, with particularly scarce research on parthenogenesis in migratory locust. This study investigates the relationship between parthenogenesis and the phase change in migratory locusts. Through comparative studies between two phases, we found that solitary locusts exhibit a higher parthenogenesis capacity compared to gregarious locusts, as evidenced by greater total oviposition quantity and higher hatching rates. However, parthenogenesis resulted in significantly lower hatching rates compared to sexually fertilized females, with distinct differences in oviposition dynamics and hatching patterns. Furthermore, we observed that gregarious locusts, when isolated after eclosion, exhibited increased parthenogenetic capacity, depending on their juvenile density. Together, this study provides insights into the understanding of insect parthenogenesis and lays basis for the potential underlying mechanism. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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22 pages, 12901 KB

Open AccessEditor’s ChoiceArticle

Metabolic Remodeling of the Tricarboxylic Acid Cycle and Glycolysis Reveals Cold-Induced Respiratory Adaptations in Streltzoviella insularis (Staudinger) (Lepidoptera: Cossidae) Larvae

by Lingxu Zhi, Ruixin Li, Baosheng Zhang, Yan Zhang, Jiahe Pei and Shixiang Zong

Insects 2025, 16(8), 864; https://doi.org/10.3390/insects16080864 - 19 Aug 2025

Cited by 5 | Viewed by 1800

Abstract

Global climate change is pushing insects into colder regions. Understanding their cold tolerance is important for predicting population dynamics. During overwintering, Streltzoviella insularis larvae activate the AMPK signaling pathway. This suggests that energy metabolism plays a key role under cold stress. In this [...] Read more.

Global climate change is pushing insects into colder regions. Understanding their cold tolerance is important for predicting population dynamics. During overwintering, Streltzoviella insularis larvae activate the AMPK signaling pathway. This suggests that energy metabolism plays a key role under cold stress. In this study, we used enzyme activity assays, LC-MS-based targeted metabolomics, and transcriptome sequencing. We focused on six key enzymes in glycolysis and the TCA cycle. We also measured related metabolites and regulatory genes. Hexokinase (HK) and citrate synthase (CS) activities were highly sensitive to temperature. HK increased then markedly decreased; CS was significantly downregulated. Pyruvate kinase (PK), isocitrate dehydrogenase (IDH), and α-ketoglutarate dehydrogenase (KGD) showed trends that matched changes in larval cold tolerance, exhibiting an up–down–up expression trend. Glycolytic metabolites (glucose-6-phosphate, fructose-6-phosphate, 1,6-fructose-diphosphate, phosphoenolpyruvic acid) peaked at −10 °C. TCA intermediates (citrate, acetyl-CoA, α-ketoglutaric acid, and isocitrate) were more abundant at 0–4 °C. Pyruvate increased significantly. PYR content showed a significant increase followed by a decrease, peaking at 0 °C. It was converted into lactate and acetyl-CoA. ATP levels dropped and then increased, reaching their lowest level at 0 °C. These results suggest a shift from aerobic to mixed aerobic–anaerobic metabolism. Transcriptome data showed differential expression of key metabolic genes such as phosphoenolpyruvate carboxykinase, phosphoglycerate kinase, and ATP synthase subunit beta. These gene changes supported the trends in enzymes and metabolites. Our findings reveal a coordinated metabolic and transcriptional response to cold. This provides a basis for understanding the cold adaptation and potential range expansion of S. insularis. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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21 pages, 1355 KB

Open AccessEditor’s ChoiceArticle

Nationwide Screening for Arthropod, Fungal, and Bacterial Pests and Pathogens of Honey Bees: Utilizing Environmental DNA from Honey Samples in Australia

by Gopika Bhasi, Gemma Zerna and Travis Beddoe

Insects 2025, 16(8), 764; https://doi.org/10.3390/insects16080764 - 25 Jul 2025

Cited by 6 | Viewed by 3085

Abstract

The European honey bee (Apis mellifera) significantly contributes to Australian agriculture, especially in honey production and the pollination of key crops. However, managed bee populations are declining due to pathogens, agrochemicals, poor forage, climate change, and habitat loss. Major threats include [...] Read more.

The European honey bee (Apis mellifera) significantly contributes to Australian agriculture, especially in honey production and the pollination of key crops. However, managed bee populations are declining due to pathogens, agrochemicals, poor forage, climate change, and habitat loss. Major threats include bacteria, fungi, mites, and pests. With the increasing demand for pollination and the movement of bee colonies, monitoring these threats is essential. It has been demonstrated that honey constitutes an easily accessible source of environmental DNA. Environmental DNA in honey comes from all organisms that either directly or indirectly aid in its production and those within the hive environments. In this study, we extracted eDNA from 135 honey samples and tested for the presence of DNA for seven key honey bee pathogens and pests—Paenibacillus larvae, Melissococcus plutonius (bacterial pathogens), Nosema apis, Nosema ceranae (microsporidian fungi), Ascosphaera apis (fungal pathogen), Aethina tumida, and Galleria mellonella (arthropod pests) by using end-point singleplex and multiplex PCR assays. N. ceranae emerged as the most prevalent pathogen, present in 57% of the samples. This was followed by the pests A. tumida (40%) and G. mellonella (37%), and the pathogens P. larvae (21%), N. apis (19%), and M. plutonius (18%). A. apis was detected in a smaller proportion of the samples, with a prevalence of 5%. Additionally, 19% of the samples tested negative for all pathogens and pests analysed. The data outlines essential information about the prevalence of significant arthropod, fungal, and bacterial pathogens and pests affecting honey bees in Australia, which is crucial for protecting the nation’s beekeeping industry. Full article

(This article belongs to the Special Issue Recent Advances in Bee Parasite, Pathogen, and Predator Interactions)

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20 pages, 4156 KB

Open AccessEditor’s ChoiceArticle

Reproductive Senescence in the Pollinator, Megachile rotundata

by Jacob B. Pithan, Brooke L. Kohler, Arun Rajamohan and Kendra J. Greenlee

Insects 2025, 16(6), 612; https://doi.org/10.3390/insects16060612 - 10 Jun 2025

Cited by 1 | Viewed by 3689

Abstract

The disposable soma theory posits that organisms allocate limited resources between reproduction, maintenance, and growth, resulting in trade-offs, particularly as they age. In this study, we examined age-related reproductive senescence in Megachile rotundata, a solitary bee and important agricultural pollinator. We hypothesized [...] Read more.

The disposable soma theory posits that organisms allocate limited resources between reproduction, maintenance, and growth, resulting in trade-offs, particularly as they age. In this study, we examined age-related reproductive senescence in Megachile rotundata, a solitary bee and important agricultural pollinator. We hypothesized that, similarly to social bees, aging females would show declines in foraging behavior and reproductive fitness. Contrary to this hypothesis, we found no evidence of reproductive senescence in M. rotundata within the timeframe observed. Instead, older females increased their foraging rate, leading to larger provisions and offspring. We also observed that older bees exhibited improved foraging efficiency, likely due to learning and muscle physiology changes. Furthermore, ovarian development showed no decline with age, indicating that reproductive capacity remains stable throughout the observed timeframe. Our results challenge conventional assumptions about reproductive senescence in solitary bees and suggest that older M. rotundata may contribute to more efficient pollination, with implications for pollinator management. This study provides new insights into the aging process in solitary bees, emphasizing the need for further research into the mechanisms behind age-related behavioral and reproductive changes. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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26 pages, 5982 KB

Open AccessEditor’s ChoiceArticle

Diverse Sublethal Effects of a Common Fungicide Impact the Behavior and Physiology of Honey Bees

by Xufeng Zhang, Qian Cao, Feng Wang, Yinyin Du, Wen Zhao, Yuan Guo and Olav Rueppell

Insects 2025, 16(6), 603; https://doi.org/10.3390/insects16060603 - 8 Jun 2025

Cited by 6 | Viewed by 2513

Abstract

Honey bees and other pollinators are key to functioning natural and managed ecosystems. However, their health is threatened by many factors, including pesticides. Spraying fungicides during flowering of fruit trees is widespread even though it directly exposes pollinators to these fungicides. Here, we [...] Read more.

Honey bees and other pollinators are key to functioning natural and managed ecosystems. However, their health is threatened by many factors, including pesticides. Spraying fungicides during flowering of fruit trees is widespread even though it directly exposes pollinators to these fungicides. Here, we report a series of experiments designed to understand how the combination of propiconazole and carbendazim, marketed in China as Chunmanchun^®, affects honey bee health. With an acute oral toxicity of 23.8 μg a.i./bee over 24 h in the laboratory, we considered the acute mortality risk from normal Chunmanchun^® applications as relatively low. However, our comprehensive studies revealed other diverse effects: Chunmanchun^® reduced memory after classic conditioning by approximately 25% and altered the activity of protective enzymes and the composition of the honey bees’ gut microbiota. Specifically, the genus Lactobacillus was decreased by ~13%, and Bartonella and Snodgrassella were increased by ~10% and ~7.5%, respectively. The gut metabolome was also disrupted in diverse ways, possibly as a functional consequence of the microbiome changes. Thus, we demonstrated numerous sublethal effects of the combination of propiconazole and carbendazim, which adds to the growing evidence that agrochemicals and fungicides in particular can harm pollinator health in subtle ways that are not captured in simple mortality assays. Full article

(This article belongs to the Special Issue Biology and Conservation of Honey Bees)

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13 pages, 5283 KB

Open AccessEditor’s ChoiceArticle

Assessing the Conservation Priority of Alpine Carabid Beetle Communities by Mapping the Index of Natural Value (INV) in Natura 2000 Habitats in the Brenta Dolomites (Italian Alps)

by Emiliano Peretti, Marco Armanini, Roberta Chirichella, Andrea Mustoni and Mauro Gobbi

Insects 2025, 16(6), 602; https://doi.org/10.3390/insects16060602 - 7 Jun 2025

Cited by 1 | Viewed by 1902

Abstract

The Dolomites (European Alps) are a UNESCO World Heritage Site known to harbor distinctive communities of carabid beetles adapted to high-altitude environments, whose composition is shaped mainly by landform and habitat type. We aimed to assess the conservation priority of carabid beetle communities [...] Read more.

The Dolomites (European Alps) are a UNESCO World Heritage Site known to harbor distinctive communities of carabid beetles adapted to high-altitude environments, whose composition is shaped mainly by landform and habitat type. We aimed to assess the conservation priority of carabid beetle communities in the Brenta mountain group (Italy). We used the Index of Natural Value (INV), based on the relative frequencies and abundances of highly specialized Alpine species, as a proxy of the sensitivity to disturbance, and, thus, to the vulnerability of the carabid beetle communities to extinction. We used information on Natura 2000 habitat cover to produce a map for identifying areas of the Brenta Dolomites inhabited by the carabid beetle communities most relevant for conservation. We also report on the main differences in terms of species composition between the investigated communities. We found a positive correlation between vulnerability and altitude. Specifically, the most vulnerable communities were recorded in high-altitude habitat types (limestone cliffs and pavements, calcareous and calcschist screes, and alpine calcareous grasslands). Alkaline fens resulted in having the least vulnerable community, while those in all other habitats (bush and forests) were found to have intermediate levels of vulnerability. Full article

(This article belongs to the Special Issue Arthropods in Ecosystem Resilience: Biodiversity, Distribution, and Conservation Strategies)

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14 pages, 6331 KB

Open AccessEditor’s ChoiceArticle

The Sensory Equipment of Diving Lice, a Host Ecology-Based Comparative Study

by Paula Olivera, Claudio R. Lazzari and María Soledad Leonardi

Insects 2025, 16(6), 574; https://doi.org/10.3390/insects16060574 - 29 May 2025

Viewed by 1440

Abstract

Seal lice (Anoplura) parasitize amphibious hosts, such as pinnipeds, and are uniquely adapted to an oceanic environment. As obligate, permanent ectoparasites feed on the blood of their hosts and are completely dependent on them. While studies have begun to explore general diving adaptations, [...] Read more.

Seal lice (Anoplura) parasitize amphibious hosts, such as pinnipeds, and are uniquely adapted to an oceanic environment. As obligate, permanent ectoparasites feed on the blood of their hosts and are completely dependent on them. While studies have begun to explore general diving adaptations, research into seal lice’s sensory biology remains limited. In contrast to the vast majority of insects, including human lice, seal lice are devoid of eyes and depend on antennal sensory reception. This study aims to describe the morphology and putative function of antennal sensilla in five seal lice species: Antarctophthirus microchir, A. carlinii, A. lobodontis, A. ogmorhini, and Lepidophthirus macrorhini, which parasitize the South American sea lion, Weddell seal, crabeater seal, leopard seal, and southern elephant seal, respectively. The antennal structures of each species were analyzed using scanning electron microscopy, and eight morphotypes were identified: spine, cuticular lobe, sensilla squamiformia, sensilla chaetica, sensilla basiconica I and II, tuft organs, and pore organs. The morphology of sensilla and their distribution on the antennal flagellum exhibited variability among genera and species. For instance, the southern elephant louse (Lepidophthirus macrorhini) is characterized by the presence of sensilla squamiformia, while Antarctophthirus spp. are distinguished by sensilla chaetica. Full article

(This article belongs to the Section Medical and Livestock Entomology)

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15 pages, 1830 KB

Open AccessEditor’s ChoiceArticle

Reproduction and Wing Differentiation of Gynoparae Are Regulated by Juvenile Hormone Signaling in Aphis gossypii

by Liuyu Wang, Jingli Lv, Xiangzhen Zhu, Kaixin Zhang, Qingyu Shi, Li Wang, Weihua Ma, Jichao Ji, Junyu Luo and Jinjie Cui

Insects 2025, 16(6), 559; https://doi.org/10.3390/insects16060559 - 25 May 2025

Cited by 1 | Viewed by 1849

Abstract

Gynopara is a specific winged type in the life history of Aphis gossypii. As a key reproduction mode between parthenogenesis and sexual reproduction, it lays sexual females in late autumn. However, little is known about gynoparae because of its rare presence in [...] Read more.

Gynopara is a specific winged type in the life history of Aphis gossypii. As a key reproduction mode between parthenogenesis and sexual reproduction, it lays sexual females in late autumn. However, little is known about gynoparae because of its rare presence in the wild and the lack of its detailed descriptions. In this study, we investigated the morphological characteristics, ovary maturation process, and key signaling pathways during the development of gynoparae of A. gossypii. With the extension of development stage, the gynoparae exhibited gradually enlarged and thickened abdomen, deepened color. Obviously differentiated wing primordia in the second instar nymphs. Two nested U-shaped zones containing a series of waxy secreta spots were present on the abdomen of the fourth instar nymphs, and these morphological characteristics could be used as important markers for identifying gynoparae. Temporal transcriptomic analysis suggested that juvenile hormone (JH) might be involved in regulating the development of gynoparae. After the application JH analog kinoprene to the first instar nymphs, almost all treated individuals failed to complete wing differentiation, and most lost the ability to produce progeny, suggesting the destructive effect of JH on wing differentiation and reproduction of gynoparae. Moreover, exogenous addition of kinoprene also significantly altered the expression levels of four key genes responsible for the synthesis and degradation of JH. Our findings reveal the mechanism by which JH regulated wing differentiation and reproductive capacity of gynoparae, which lay a foundation for the further research on reproduction mode switch in aphids in the future. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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27 pages, 1679 KB

Open AccessEditor’s ChoiceReview

Insect Pest Control from Chemical to Biotechnological Approach: Constrains and Challenges

by Stefano Civolani, Massimo Bariselli, Riccardo Osti and Giovanni Bernacchia

Insects 2025, 16(5), 528; https://doi.org/10.3390/insects16050528 - 15 May 2025

Cited by 15 | Viewed by 6447

Abstract

The large growth in the global population requires new solutions for the control of harmful insects that compete for our food. Changing regulatory requirements and public perception, together with the continuous evolution of resistance to conventional insecticides, also require, in addition to innovative [...] Read more.

The large growth in the global population requires new solutions for the control of harmful insects that compete for our food. Changing regulatory requirements and public perception, together with the continuous evolution of resistance to conventional insecticides, also require, in addition to innovative molecules with different modes of action, new non-chemical control strategies that can help maintain efficient integrated pest management programs. The last 30 years have inaugurated a new era characterised by the discovery of new mechanisms of action and new chemical families. Although European programs also promote a green deal in the crop protection sector, the existing thorough regulations slow down its spread and the adoption of new products. In light of these changes, this review will describe in more detail the dynamics of discovery and registration of new conventional insecticides and the difficulties that the agrochemical industries encounter. Subsequently, the different innovative control strategies alternative to conventional insecticides based on natural substances of different origin, entomopathogenic microorganisms, semiochemical and semiophysical compounds, and classical and augmentative biological control will be described. The advantages of these green strategies will be illustrated and also the constrains to their diffusion and commercialisation. Finally, the main biotechnological discoveries will be described, from transgenic plants to symbiotic control, classical genetic control, and, more recently, control based on insect genomic transformation or on RNAi. These new biotechnologies can revolutionise the sector despite some constrains related to the regulatory restrictions present in different countries. Full article

(This article belongs to the Special Issue Chemical Toxicology and Insecticide Resistance on Insect Pests)

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18 pages, 1588 KB

Open AccessEditor’s ChoiceReview

The Role of Red Wood Ants (Formica rufa Species Group) in Central European Forest Ecosystems—A Literature Review

by Ágnes Fürjes-Mikó, Sándor Csősz, Márton József Paulin and György Csóka

Insects 2025, 16(5), 518; https://doi.org/10.3390/insects16050518 - 13 May 2025

Cited by 5 | Viewed by 6557

Abstract

Red wood ants (RWA), belonging to the Formica rufa species group, play a crucial and fascinating role in Central Europe’s forest ecosystems. They have a high variety of effects, which they exert around their nests. Their generalist feeding on prey in the canopies [...] Read more.

Red wood ants (RWA), belonging to the Formica rufa species group, play a crucial and fascinating role in Central Europe’s forest ecosystems. They have a high variety of effects, which they exert around their nests. Their generalist feeding on prey in the canopies of trees lowers the frequency of defoliator outbreaks, as well as increases local biodiversity. Nearly half of their diverse diet is insects, including species considered harmful by foresters. They also have a mutualistic relation with honeydew-producing aphids and planthoppers, which connection has unclear effects on the forests. The habit of RWAs building nests could also positively influence soil composition, due to its structure and high amount of organic matter, which could potentially benefit tree growth. RWAs are also known to enhance the species richness of forests by supporting various myrmecophilous species associated with them. In this study, we review the role of RWAs in forest protection, drawing on the literature focusing on Hungary and Central Europe. Full article

(This article belongs to the Special Issue The Richness of the Forest Microcosmos)

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21 pages, 9756 KB

Open AccessEditor’s ChoiceArticle

Extensive DNA Barcoding of Lepidoptera of Crete (Greece) Reveals Significant Taxonomic and Faunistic Gaps and Supports the First Comprehensive Checklist of the Island’s Fauna

by Peter Huemer, Kai Berggren, Leif Aarvik, Erwin Rennwald, Axel Hausmann, Andreas Segerer, Giorgia Staffoni, Aina Mærk Aspaas, Apostolos Trichas and Paul D. N. Hebert

Insects 2025, 16(5), 438; https://doi.org/10.3390/insects16050438 - 22 Apr 2025

Cited by 9 | Viewed by 6384

Abstract

Comprehensive genetic surveys of Lepidoptera are still largely lacking across most of the eastern Mediterranean. Consequently, there is a lack of modern, taxonomically validated checklists that meet current scientific standards. In this study, we analyze the butterfly and moth fauna of Crete (Greece) [...] Read more.

Comprehensive genetic surveys of Lepidoptera are still largely lacking across most of the eastern Mediterranean. Consequently, there is a lack of modern, taxonomically validated checklists that meet current scientific standards. In this study, we analyze the butterfly and moth fauna of Crete (Greece) for the first time, based on 3110 DNA barcode sequences, primarily obtained from specimens based on our own sampling program. Building on these data, and incorporating previously published records from print sources and online forums, we establish the first comprehensive checklist of the island’s fauna. In total, the occurrence of 1230 species from 62 families is confirmed, with 724 of them genetically verified. Among them, 75 species appear to be island endemics. The checklist includes 125 newly recorded species for Crete, validated by DNA barcoding (with 36 also being new for Greece), along with 23 species confirmed solely through morphological study, and another 16 only documented by photographs. Conversely, 212 previously reported species had to be removed as likely invalid. Furthermore, 112 unidentified sequence clusters (BINs—Barcode Index Numbers) were documented, taxonomic uncertainties that will require future integrative resolution. Full article

(This article belongs to the Section Insect Systematics, Phylogeny and Evolution)

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27 pages, 6986 KB

Open AccessEditor’s ChoiceArticle

Genome-Wide Identification and Expression Profiling of Glycosidases, Lipases, and Proteases from Invasive Asian Palm Weevil, Rhynchophorus ferrugineus

by Nazmi Harith-Fadzilah, Mohammad Nihad, Mohammed Ali AlSaleh, Abdulqader Yaslam Bazeyad, Subash-Babu Pandurangan, Kashif Munawar, Arya Vidyawan, Hattan A. Alharbi, Jernej Jakše, Arnab Pain and Binu Antony

Insects 2025, 16(4), 421; https://doi.org/10.3390/insects16040421 - 17 Apr 2025

Cited by 2 | Viewed by 3073

Abstract

The red palm weevil, Rhynchophorus ferrugineus, is a destructive, invasive pest to a diverse range of palm plantations globally. Commonly used broad-range chemical insecticides for insect control pose high risks to non-target organisms, humans, and the environment. A bio-rational approach of screening [...] Read more.

The red palm weevil, Rhynchophorus ferrugineus, is a destructive, invasive pest to a diverse range of palm plantations globally. Commonly used broad-range chemical insecticides for insect control pose high risks to non-target organisms, humans, and the environment. A bio-rational approach of screening natural small-molecule inhibitors that specifically target R. ferrugineus proteins critical to its life processes can pave the way for developing novel bioinsecticides. Digestive enzymes (DEs), which impair feeding on plants (herbivory), are promising targets. We generated de novo transcriptomes, annotated DE-related genes from the R. ferrugineus gut and abdomen, manually annotated the DE gene family from the recently available genome and our transcriptome data, and reported 34 glycosidases, 85 lipases, and 201 proteases. We identified several tandem duplicates and allelic variants from the lipase and protease families, notably, 10 RferLip and 21 RferPro alleles, which emerged primarily through indels and single-site substitution. These alleles may confer enhanced digestive lipolysis and proteolysis. Phylogenetic analyses identified and classified different subfamilies of DEs and revealed close evolutionary relationships with other coleopterans. We assessed select candidate DEs’ activity and the potential for inhibition in silico to better understand the herbivory arsenal. In silico analysis revealed that the selected enzymes exhibited similar ligand-binding affinity to their corresponding substrate, except for protease aminopeptidase N, RferPro40, which exhibited poorer affinity to the inhibitor bestatin. Overall, our study serves as a foundation for further functional analysis and offers a novel target for the development of a novel bio-rational insecticide for R. ferrugineus. Full article

(This article belongs to the Special Issue Natural Metabolites as Biocontrol Agents of Insect Pests)

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29 pages, 2547 KB

Open AccessEditor’s ChoiceArticle

Mechanisms Maintaining Mitochondrial DNA Polymorphisms: The Role of Mito-Nuclear Interactions, Sex-Specific Selection, and Genotype-by-Environment Interactions in Drosophila subobscura

by Pavle Erić, Marija Savić Veselinović, Aleksandra Patenković, Marija Tanasković, Bojan Kenig, Katarina Erić, Boris Inđić, Stefan Stanovčić and Mihailo Jelić

Insects 2025, 16(4), 415; https://doi.org/10.3390/insects16040415 - 15 Apr 2025

Viewed by 1999

Abstract

Experimental mito-nuclear introgression lines (MNILs) were established by backcrossing isofemale lines of D. subobscura originating from the same populations. MNILs were subjected to a series of life-history experiments designed to test the fitness of the bearers of different combinations of two main mtDNA [...] Read more.

Experimental mito-nuclear introgression lines (MNILs) were established by backcrossing isofemale lines of D. subobscura originating from the same populations. MNILs were subjected to a series of life-history experiments designed to test the fitness of the bearers of different combinations of two main mtDNA haplotypes on their own nuclear background, as well as on the background of the opposite haplotype. By having 11 replicas of the four mito-nuclear combinations, we could test not only the adaptive significance of the differences between the two main haplotypes but also the influence of additional variation present within each of the 11 combinations on fitness. Testing the fitness of individuals of both sexes enabled us to examine if sex-specific selection has a role in maintaining the frequencies of the two mtDNA haplotypes in nature. Conducting the fitness assays on two different temperatures enabled us to test whether different temperatures favor specific mtDNA haplotypes or mito-nuclear genotypes and consequently promote stable sympatric mtDNA variation. The results show weak signature of genotype-by-environment interactions, and no sex-specific selection regarding differences between the two main haplotypes. However, individual models across different life-history components showed these two mechanisms at play in promoting mtDNA variability present in specific mito-nuclear crosses. Our models show that mito-nuclear interactions are, in fact, more important as units of selection. Full article

(This article belongs to the Section Insect Molecular Biology and Genomics)

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13 pages, 4819 KB

Open AccessEditor’s ChoiceArticle

Habitat Suitability Analysis for Luehdorfia chinensis Leech, 1893 (Lepidoptera: Papilionidae) in the Middle and Lower Yangtze River: A Study Based on the MaxEnt Model

by Anqi Chen, Biyu Liu, Rui Zhou, Hui Zhang, Lan Zhou, Xizhu Xie, Zhihang Zhuo and Danping Xu

Insects 2025, 16(4), 396; https://doi.org/10.3390/insects16040396 - 9 Apr 2025

Cited by 5 | Viewed by 2438

Abstract

L. chinensis is a National Grade II Protected Animal in China, and predicting its suitable habitats in the middle and lower reaches of the Yangtze River is crucial for developing effective conservation strategies. This study uses methods such as the MaxEnt model to [...] Read more.

L. chinensis is a National Grade II Protected Animal in China, and predicting its suitable habitats in the middle and lower reaches of the Yangtze River is crucial for developing effective conservation strategies. This study uses methods such as the MaxEnt model to predict suitable habitats for L. chinensis in the region, providing a scientific basis for species conservation. The model results show that the AUC value of MaxEnt is 0.989, indicating excellent predictive performance. Under current climatic conditions, the area of highly suitable habitats for L. chinensis in the middle and lower reaches of the Yangtze River is 75.1 × 10³ km², accounting for 8.8% of the total area of the region. However, under the SSP2-4.5 climate scenario, the predicted results indicate a general decline in suitable habitats for the species. This change signals that the survival of L. chinensis will face significant risks in the future, highlighting the urgent need to develop and implement scientifically effective conservation measures. Full article

(This article belongs to the Collection Butterfly Diversity and Conservation)

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16 pages, 2250 KB

Open AccessEditor’s ChoiceArticle

Chronic Exposure to Field-Level Thiamethoxam Impairs Gut Tissue and Reduces Honeybee (Apis cerana) Survival

by Yulong Guo, Changsheng Ma, Wenzheng Zhao, Haiou Kuang, Yakai Tian, Haoyuan Zhang, Yunfei Xue, Hongmei Li-Byarlay, Kun Dong and Xueyang Gong

Insects 2025, 16(4), 372; https://doi.org/10.3390/insects16040372 - 1 Apr 2025

Cited by 7 | Viewed by 2629

Abstract

Pesticides such as neonicotinoids frequently harm beneficial insect pollinators and affect their survival, social behavior, digestive system, and metabolism. Investigating the mechanisms behind these impairments is crucial for enhancing pesticide risk assessments. Apis cerana, a native honeybee species in Asia, has received [...] Read more.

Pesticides such as neonicotinoids frequently harm beneficial insect pollinators and affect their survival, social behavior, digestive system, and metabolism. Investigating the mechanisms behind these impairments is crucial for enhancing pesticide risk assessments. Apis cerana, a native honeybee species in Asia, has received limited research attention regarding the toxicological mechanisms of thiamethoxam (TMX) exposure. We exposed newly emerged worker bees of A. cerana to a field-relevant dose of TMX (400 ng/g) under laboratory conditions to examine whether TMX exposure triggers similar or distinct effects in different biological processes and tissues. Our results demonstrate that TMX damages the gut cell structure and significantly increases mortality. Gut transcriptomic analysis revealed that the activation of signaling pathways such as glycosphingolipid biosynthesis, Notch signaling, and Wnt signaling likely contributed to structural damage in gut cells. Head transcriptomic results indicated that the activation of pathways including pyruvate metabolism, glycolysis/gluconeogenesis, thiamine metabolism, and riboflavin metabolism might negatively affect the stability of the neural system in A. cerana. The metabolic dysfunction of glycine, serine, threonine, as well as glycerophospholipids potentially impairs the neural system, leading to behavioral abnormalities and mortality. In summary, field-level TMX damages the gut cell structure, destabilizes the neural system, and increases the mortality rate of A. cerana. These findings demonstrate that TMX exposure induces complex, tissue-specific effects. This study provides a comprehensive understanding of the molecular and physiological impacts of TMX on A. cerana, offering valuable insights for the conservation and protection of this important pollinator species. Full article

(This article belongs to the Section Social Insects and Apiculture)

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14 pages, 1078 KB

Open AccessEditor’s ChoiceArticle

Honey Bees Can Use Sequence Learning to Predict Rewards from a Prior Unrewarded Visual Stimulus

by Bahram Kheradmand, Ian Richardson-Ramos, Sarah Chan, Claudia Nelson and James C. Nieh

Insects 2025, 16(4), 358; https://doi.org/10.3390/insects16040358 - 31 Mar 2025

Cited by 1 | Viewed by 2766

Abstract

Learning to anticipate upcoming events can increase fitness by allowing animals to choose the best course of action, and many species can learn sequences of events and anticipate rewards. To date, most studies have focused on sequences over short time scales such as [...] Read more.

Learning to anticipate upcoming events can increase fitness by allowing animals to choose the best course of action, and many species can learn sequences of events and anticipate rewards. To date, most studies have focused on sequences over short time scales such as a few seconds. Whereas events separated by a few seconds are easily learned, events separated by longer delays are typically more difficult to learn. Here, we show that honey bees (Apis mellifera) can learn a sequence of two visually distinct food sources alternating in profitability every few minutes. Bees were challenged to learn that the rewarded pattern was the one that was non-rewarded on the prior visit. We show that bees can predict and choose the feeder that will be rewarding upon their next approach more frequently than predicted by chance, and they improve with experience, with 64% correct choices made in the second half of their visit sequence (N = 320 visits by 20 different bees). These results increase our understanding of honey bee visual sequential learning and further demonstrate the flexibility of foragers’ learning strategies. Full article

(This article belongs to the Section Social Insects and Apiculture)

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28 pages, 390 KB

Open AccessEditor’s ChoiceReview

Patterns and Mechanisms of Niche Partitioning Between Related Parasitoids (Hymenoptera) Sharing the Same Host Species

by Vladimir E. Gokhman

Insects 2025, 16(4), 340; https://doi.org/10.3390/insects16040340 - 25 Mar 2025

Cited by 6 | Viewed by 4950

Abstract

Related species of parasitoid Hymenoptera often coexist on a certain host, but many details of interactions between these organisms remain unclear. The present review summarizes the main existing concepts and facts and suggests principal patterns and mechanisms that allow for the coexistence of [...] Read more.

Related species of parasitoid Hymenoptera often coexist on a certain host, but many details of interactions between these organisms remain unclear. The present review summarizes the main existing concepts and facts and suggests principal patterns and mechanisms that allow for the coexistence of several members of a particular parasitoid genus at the expense of the same host. Although the successful introduction of exotic parasitic wasps into the existing ecosystems often leads to the competitive displacement of related parasitoids, mere spatial and/or temporal niche partitioning between these insects is also possible. Nevertheless, many cases of coexistence of related wasp species on the same host defy simple explanations since they apparently result from complex interactions between the host and its parasitoids. The main characteristics of the oviposition process, i.e., egg volume, fecundity, and duration of the egg-laying period, are likely to correlate with other basic features of life-history strategies in parasitoid Hymenoptera. Specialist parasitic wasps often aggregate over the host patches, whereas generalists can be randomly distributed, thus reducing the degree of interspecific competition among parasitoids. However, some of the coexisting parasitic wasps, usually the weakest competitors, must also have access to enemy-free space to survive. Full article

(This article belongs to the Special Issue Taxonomy and Biology of Parasitoids and Potential for Their Biological Control)

31 pages, 39485 KB

Open AccessEditor’s ChoiceArticle

Subfossil Insects of the Kebezen Site (Altai Mountains): New Data on the Last Deglaciation Environment

by Anna A. Gurina, Natalia I. Agrikolyanskaya, Roman Yu. Dudko, Yuri E. Mikhailov, Alexander A. Prokin, Sergei V. Reshetnikov, Alexey S. Sazhnev, Alexey Yu. Solodovnikov, Evgenii V. Zinovyev and Andrei A. Legalov

Insects 2025, 16(3), 321; https://doi.org/10.3390/insects16030321 - 19 Mar 2025

Cited by 4 | Viewed by 3441

Abstract

This paper focuses on insect remains found at the Kebezen site (51.93600° N, 87.09665° E) on the Turachak stream, Altai Republic, Russia, in layers ranging in age from 20.1 to 19.3 cal ky BP, corresponding to the onset of the last deglaciation. Coleoptera, [...] Read more.

This paper focuses on insect remains found at the Kebezen site (51.93600° N, 87.09665° E) on the Turachak stream, Altai Republic, Russia, in layers ranging in age from 20.1 to 19.3 cal ky BP, corresponding to the onset of the last deglaciation. Coleoptera, represented by 105 species from 21 families, predominate in the sediments, with the families Carabidae, Staphylinidae, Chrysomelidae and Scolytidae being the most numerous. The insect assemblage of Kebezen contrasts sharply with the Late Pleistocene entomofauna of the West Siberian Plain, but it is similar with the assemblages of the geographically close Lebed site (Oldest and Older Dryas). Also, it corresponds well with the modern middle-altitude entomofauna of the mountains of north-eastern Altai. Based on such entomological data, boreal forests with a predominance of Picea and alpine meadows, as well as a cold and humid climate, were reconstructed for the Kebezen site. Changes in the ecological composition of beetles were traced during sedimentation: the most complete spectrum of the basal layer was replaced by a complex with a significant predominance of meadow and water-edge species, after which the proportions of shrub species, bryophilous species, and forest species consistently increased. Such changes correspond to the course of primary succession initiated by a catastrophic factor such as a megaflood. Full article

(This article belongs to the Special Issue Fossil Insects: Diversity and Evolutionary History)

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18 pages, 2723 KB

Open AccessEditor’s ChoiceArticle

Rahnella aquatilis Isolated from Aedes albopictus Impairs Mosquito Reproduction Capacity

by Ling Gu, Lin Li, Jinyang Sun, Yongqiao Zhao, Kai Wan, Meichun Zhang, Julin Li, Meihua Zhang, Guoding Zhu and Jianxia Tang

Insects 2025, 16(3), 257; https://doi.org/10.3390/insects16030257 - 2 Mar 2025

Cited by 5 | Viewed by 2777

Abstract

Aedes albopictus is one of the most important vectors of Dengue, which poses a serious threat to public health. The bacterial microbiota has an effect on the parameters of mosquitos, such as larval development and fecundity, and it has emerged as a promising [...] Read more.

Aedes albopictus is one of the most important vectors of Dengue, which poses a serious threat to public health. The bacterial microbiota has an effect on the parameters of mosquitos, such as larval development and fecundity, and it has emerged as a promising field to be explored for novel environmentally friendly control strategies. Rahnella sp. are present in many insects, including Ae. Albopictus, and play a role in bacterial–insect interactions; however, the role of the bacteria in mosquito biology has not yet been characterized. In this study, we characterized the Rahnella isolate RAeA1 obtained from Ae. albopcitus, and its colonization stability in Ae. albopictus was investigated by generating GFP-tagged bacteria. The influences of the bacteria on larval development and mosquito reproductive capacity were evaluated by inoculating RAeA1 in axenic larvae and antibiotic-treated adult mosquitoes, respectively. The results indicated that RAeA1, which is widespread in the field population of Ae. albopictus, can be transmitted directly from the parental strain to the progeny and can rescue axenic larvae developing into adults with a prolonged development time to pupation. RAeA1 inoculation can impair egg production and ovary maturation, as well as reducing the synthesis of ecdysteroids and vitellogenin in Ae. albopictus females. Overall, our results provide a thorough study of bacterium function characterization that will facilitate the development of potential strategies in relation to the design of microbiomes for vector control. Full article

(This article belongs to the Section Medical and Livestock Entomology)

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31 pages, 469 KB

Open AccessEditor’s ChoiceReview

What Can We Learn from Dissecting Tortricid Females About the Efficacy of Mating Disruption Programs?

by Alan Lee Knight, Michele Preti and Esteban Basoalto

Insects 2025, 16(3), 248; https://doi.org/10.3390/insects16030248 - 28 Feb 2025

Cited by 7 | Viewed by 3307

Abstract

Female mating success for the tortricids codling moth (CM), Cydia pomonella, Oriental fruit moth (OFM), Grapholita molesta, European grape vine moth (EGVM), Lobesia botrana, and five leafroller (LR) species under various mating disruption (MD) programs was reviewed at a time [...] Read more.

Female mating success for the tortricids codling moth (CM), Cydia pomonella, Oriental fruit moth (OFM), Grapholita molesta, European grape vine moth (EGVM), Lobesia botrana, and five leafroller (LR) species under various mating disruption (MD) programs was reviewed at a time when new dual sex lures can provide alternative tools to assess female mating. Previous reliance on passive assessments such as tethering and virgin female-baited traps with laboratory moths are at odds with active trapping methods of wild moths. Additive factors such as delayed mating, adjustments in female behaviors, and greater levels of natural control may or may not contribute to the apparent success of MD. Current MD programs are not based solely on research, as economics and commercialization require some compromise. The complete sex pheromone blend is not always used. A delay in mating has been reported from the field with one study and suggested that reductions in fecundity would likely be minimal. There is no evidence that MD works better with low population densities. MD is an established technology, but the new dual sex lures are showing that the density of mated females is rather high. Efforts to improve the efficacy of MD are ongoing with a small cadre of researchers. Full article

(This article belongs to the Special Issue Inter- and Intra-specific Interactions by Semiochemicals in Arthropods)

17 pages, 6113 KB

Open AccessEditor’s ChoiceArticle

On the Study of Joint YOLOv5-DeepSort Detection and Tracking Algorithm for Rhynchophorus ferrugineus

by Shuai Wu, Jianping Wang, Wei Wei, Xiangchuan Ji, Bin Yang, Danyang Chen, Huimin Lu and Li Liu

Insects 2025, 16(2), 219; https://doi.org/10.3390/insects16020219 - 17 Feb 2025

Cited by 7 | Viewed by 2979

Abstract

The Red Palm Weevil (RPW, Rhynchophorus ferrugineus) is a destructive pest of palm plants that can cause the death of the entire plant when infested. To enhance the efficiency of RPW control, a novel detection and tracking algorithm based on the joint [...] Read more.

The Red Palm Weevil (RPW, Rhynchophorus ferrugineus) is a destructive pest of palm plants that can cause the death of the entire plant when infested. To enhance the efficiency of RPW control, a novel detection and tracking algorithm based on the joint YOLOv5-DeepSort algorithm is proposed. Firstly, the original YOLOv5 is improved by adding a small object detection layer and an attention mechanism. At the same time, the detector of the original DeepSort is changed to the improved YOLOv5. Then, a historical frame data module is introduced into DeepSort to reduce the number of target identity (ID) switches while maintaining detection and tracking accuracy. Finally, an experiment is conducted to evaluate the joint YOLOv5-DeepSort detection and tracking algorithm. The experimental results show that, in terms of detectors, the improved YOLOv5 model achieves a mean average precision (mAP@.5) of 90.1% and a precision (P) of 93.8%. In terms of tracking performance, the joint YOLOv5-DeepSort algorithm achieves a Multiple Object Tracking Accuracy (MOTA) of 94.3%, a Multiple Object Tracking Precision (MOTP) of 90.14%, reduces ID switches by 33.3%, and realizes a count accuracy of 94.1%. These results demonstrate that the improved algorithm meets the practical requirements for RPW field detection and tracking. Full article

(This article belongs to the Special Issue Artificial Intelligence (AI) and Insect Pests Management: Securing Food Security, Human Health, and Natural Resources)

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16 pages, 3662 KB

Open AccessEditor’s ChoiceArticle

Programmable LED Array for Evaluating Artificial Light Sources to Improve Insect Trapping

by Mohsen Paryavi, Keith Weiser, Michael Melzer, Damon Crook, Chandrika Ramadugu and Daniel M. Jenkins

Insects 2025, 16(2), 170; https://doi.org/10.3390/insects16020170 - 6 Feb 2025

Cited by 5 | Viewed by 5034

Abstract

We developed a programmable LED array to evaluate different wavelength illumination (UV, blue, green, yellow, amber, and red) and modulation schemes to improve catch rates in insect traps. The device can communicate through Bluetooth^® with a simple Android app to update the [...] Read more.

We developed a programmable LED array to evaluate different wavelength illumination (UV, blue, green, yellow, amber, and red) and modulation schemes to improve catch rates in insect traps. The device can communicate through Bluetooth^® with a simple Android app to update the operational settings to facilitate field experiments, including which LEDs to operate, when to operate (always, night only, or predefined intervals after sunset and/or before sunrise), and to change the LED intensities/modulation during operation. We used the devices to evaluate different wavelengths to improve catches in traps for coconut rhinoceros beetle (CRB; Oryctes rhinoceros Linnaeus) in the field, as well as to evaluate lighting preferences of Asian citrus psyllid (ACP; Diaphorina citri Kuwayama). In both cases, insects were most strongly attracted to constant UV illumination. However, CRB avoided traps with any “visible” wavelength LEDs placed in panels of traps, while ACP was moderately attracted to blue, yellow, and amber. For CRB, UV illumination of cups at the bottom of panel traps reduced catch rates compared to UV illumination higher in the panels of traps, consistent with observations of dorsal orientation towards light observed by other researchers in nocturnal beetles and moths. Finally, we provide some hardware design recommendations to improve the energy efficiency of similar devices for more widespread deployment in insect traps and for controlling the LEDs to evaluate the effects of intensity and modulation with minimal pulsing, which our observations suggest may result in insects avoiding traps. Full article

(This article belongs to the Collection Biocontrol and Behavioral Approaches to Manage Invasive Insects)

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12 pages, 5748 KB

Open AccessEditor’s ChoiceArticle

Roles of Vitellogenin and Its Receptor Genes in Female Reproduction of the Cigarette Beetle, Lasioderma serricorne

by Qian Guo, Mingxun Zu, Deqian Liu, Yi Yan, Wenjia Yang and Kangkang Xu

Insects 2025, 16(2), 175; https://doi.org/10.3390/insects16020175 - 6 Feb 2025

Cited by 10 | Viewed by 2948

Abstract

Vitellogenin (Vg) and the vitellogenin receptor (VgR) play essential roles in insect reproductive development. However, the functions of Vg and VgR genes in Lasioderma serricorne, an important insect pest of stored products, are unknown. We identified and characterized these two genes, designated [...] Read more.

Vitellogenin (Vg) and the vitellogenin receptor (VgR) play essential roles in insect reproductive development. However, the functions of Vg and VgR genes in Lasioderma serricorne, an important insect pest of stored products, are unknown. We identified and characterized these two genes, designated LsVg and LsVgR, in L. serricorne. The open reading frames of LsVg and LsVgR were 5232 and 5529 bp, encoding 1743 and 1842 amino acid residues, respectively. Both LsVg and LsVgR were predominantly expressed in female adults and exhibited the highest expression in ovaries. The RNAi-mediated silencing of LsVg or LsVgR significantly decreased the average length of ovarian tubes and oocytes and severely affected ovarian development. The Knockdown of LsVg or LsVgR significantly reduced the oviposition period, the number of eggs laid, and the egg hatching rate. Females injected with dsLsVg and dsLsVg + VgR were found to had decreased vitellogenin content. The co-silencing of LsVg and LsVgR had a more pronounced effect on reducing the oviposition period and female fecundity in L. serricorne. This study revealed the importance of LsVg and LsVgR in regulating female reproduction and shows their potential as targets for RNAi-based control of L. serricorne. Full article

(This article belongs to the Special Issue Arthropod Reproductive Biology)

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14 pages, 2638 KB

Open AccessEditor’s ChoiceArticle

Losses of Foliage to Defoliating Insects Increase with Leaf Damage Diversity Due to the Complementarity Effect

by Mikhail V. Kozlov and Vitali Zverev

Insects 2025, 16(2), 139; https://doi.org/10.3390/insects16020139 - 31 Jan 2025

Cited by 2 | Viewed by 2854

Abstract

The functioning of ecosystems critically depends on biodiversity. However, the effects of herbivore diversity on plant damage caused by herbivore feeding remain underexplored. In this study, we tested the prediction that relative losses of foliage to defoliating insects increase with leaf damage diversity [...] Read more.

The functioning of ecosystems critically depends on biodiversity. However, the effects of herbivore diversity on plant damage caused by herbivore feeding remain underexplored. In this study, we tested the prediction that relative losses of foliage to defoliating insects increase with leaf damage diversity (LDD), and we also explored the mechanisms underlying the observed LDD patterns. We measured insect herbivory in 501 individuals of three deciduous woody species (Betula pubescens, Salix phylicifolia, and Vaccinium uliginosum) across 38 localities in north-western Russia, collected 8844 leaves damaged by defoliating insects, classifying the 21,073 feeding events observed in these leaves into 29 damage types. Overall, LDD significantly decreased with increasing latitude but showed no variation along elevation or pollution gradients. Herbivory weakly but significantly increased with increasing LDD, and a strong positive correlation between the rarefied number of leaf damage types and their evenness provided evidence for the complementarity effect underlying this herbivory increase, indicating that insects producing different leaf damage types differ in their resource use. Full article

(This article belongs to the Section Insect Ecology, Diversity and Conservation)

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16 pages, 4245 KB

Open AccessEditor’s ChoiceArticle

Online Crowdsourced Data from iNaturalist Can Assist Monitoring of Invasive Mosquitoes

by Benjamin Cull

Insects 2025, 16(2), 128; https://doi.org/10.3390/insects16020128 - 28 Jan 2025

Cited by 4 | Viewed by 3328

Abstract

Invasive mosquitoes continue to spread, increasing the threat of mosquito-borne disease. Ongoing mosquito surveillance is necessary to track the introduction and establishment of these species in new areas and implement appropriate public health and vector control measures. Contributions from citizen science initiatives have [...] Read more.

Invasive mosquitoes continue to spread, increasing the threat of mosquito-borne disease. Ongoing mosquito surveillance is necessary to track the introduction and establishment of these species in new areas and implement appropriate public health and vector control measures. Contributions from citizen science initiatives have been an important component in detecting, controlling, and raising awareness of invasive mosquitoes. The open-access biodiversity platform iNaturalist is an extensive source of human observations of wildlife, including arthropod vectors, and can be a useful supplementary tool for passive vector surveillance. In this study, the utility of iNaturalist data to support invasive mosquito surveillance was assessed by examining the distribution and seasonal data on four invasive Aedes species (IAS) in Europe and neighbouring countries. Almost 16,000 iNaturalist observations of mosquitoes were examined across 62 countries; 13% were identified as IAS, with a further 2% considered probable IAS. These included 16 observations of Aedes aegypti, 1582 Aedes albopictus, 373 Aedes japonicus, and 58 Aedes koreicus. iNaturalist observations of IAS were present in most known areas of establishment, but potential new regions of spread were also identified. These results further support the use of iNaturalist data as a low-cost source of arthropod data to assist existing vector surveillance. Full article

(This article belongs to the Special Issue Control and Surveillance of Mosquitoes to Reduce the Spread of Mosquito-Borne Disease)

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22 pages, 5192 KB

Open AccessEditor’s ChoiceArticle

Structural and Functional Analysis of Hemoglobin Binding to the Peritrophic Matrix During Blood Digestion in Aedes aegypti

by Karla Barreto da Silva Orozimbo, Desiely da Silva Gusmão Tauil, Aline Melila Licurgo, Felipe Figueirôa Moreira, Jucélia da Silva Araújo, Maria Aparecida Aride Bertonceli, Sérgio Henrique Seabra, Olga Lima Tavares Machado and Francisco José Alves Lemos

Insects 2025, 16(2), 116; https://doi.org/10.3390/insects16020116 - 24 Jan 2025

Cited by 4 | Viewed by 3244

Abstract

The Aedes aegypti mosquito is responsible for transmitting pathogens such as the Dengue, Zika, and Chikungunya viruses. The peritrophic matrix (PM) is an extracellular chitin-rich structure that lines the midgut of arthropods, providing a crucial protective barrier for the gut epithelium against mechanical [...] Read more.

The Aedes aegypti mosquito is responsible for transmitting pathogens such as the Dengue, Zika, and Chikungunya viruses. The peritrophic matrix (PM) is an extracellular chitin-rich structure that lines the midgut of arthropods, providing a crucial protective barrier for the gut epithelium against mechanical damage, ingested pathogens, and toxic substances. During blood digestion, hemoglobin is lysed, releasing free heme into the midgut lumen. Part of this heme binds strongly to the PM, mitigating its harmful effects on the mosquito epithelial cells. Our study focused on investigating the interaction dynamic between hemoglobin and the PM during blood digestion in A. aegypti. Optical microscopy was employed to observe the temporal progression of blood digestion in the A. aegypti midgut, highlighting significant morphological changes in the blood bolus. An electrophoresis analysis revealed distinct protein bands in the PM extract, some of which were associated with hemoglobin and its subunits. The presence of PM-associated hemoglobin was confirmed by amino-terminal sequencing and an immunoblot analysis using anti-hemoglobin antibodies. Furthermore, fluorescence microscopy revealed overlapping labeling between hemoglobin and chitin, suggesting an interaction between hemoglobin and PM chitin. Corroborating these results, hemoglobin showed an affinity with chitin in the chromatography and molecular docking assays, in which the hemoglobin subunits interacted with the oligosaccharide (NAG)₄. Thus, hemoglobin may perform a function similar to that of peritrophins. Further experiments demonstrated the protective role of the PM against hemoglobin proteolysis during blood digestion. Overall, this study provides valuable insights into the intricate interactions between hemoglobin and the PM, enhancing our understanding of mosquito digestive physiology and potentially contributing to the development of vector control strategies. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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15 pages, 2415 KB

Open AccessEditor’s ChoiceReview

Effects of Microbes on Insect Host Physiology and Behavior Mediated by the Host Immune System

by Shan Zhang, Zhengyan Wang, Qiong Luo, Lizhen Zhou, Xin Du and Yonglin Ren

Insects 2025, 16(1), 82; https://doi.org/10.3390/insects16010082 - 15 Jan 2025

Cited by 67 | Viewed by 4927

Abstract

Innate immunity is critical for insects to adjust to complicated environments. Studying the insect immune system can aid in identifying novel insecticide targets and provide insights for developing novel pest control strategies. Insects recognize environmental pathogens through pattern recognition receptors, thus activating the [...] Read more.

Innate immunity is critical for insects to adjust to complicated environments. Studying the insect immune system can aid in identifying novel insecticide targets and provide insights for developing novel pest control strategies. Insects recognize environmental pathogens through pattern recognition receptors, thus activating the innate immune system to eliminate pathogens. The innate immune system of insects primarily comprises cellular immunity and humoral immunity. Toll, immune deficiency, and Janus kinase/signal transducers and activators of transcription are the main signaling pathways regulating insect humoral immunity. Nevertheless, increasing research has revealed that immune signaling activated by microbes also performs non-immune roles while exerting immune roles, and insulin signaling performs a key role in mediating the connection between the immune system and non-immune physiological activities. Therefore, this paper first briefly reviews the main innate immune signaling and insulin signaling of insects, then summarizes the relationship between immune signaling activated by microbes and insect growth and development, reproduction, pesticide resistance, chemical communication, cell turnover, lifespan, sleep, energy generation pathways and their possible underlying mechanisms. Future research directions and methodologies are also proposed, aiming to provide insights into further study on the physiological mechanism linking microbes and insect hosts. Full article

(This article belongs to the Special Issue Research on Insect Interactions with Symbionts and Pathogens)

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13 pages, 1331 KB

Open AccessEditor’s ChoiceArticle

An AI-Based Digital Scanner for Varroa destructor Detection in Beekeeping

by Daniela Scutaru, Simone Bergonzoli, Corrado Costa, Simona Violino, Cecilia Costa, Sergio Albertazzi, Vittorio Capano, Marko M. Kostić and Antonio Scarfone

Insects 2025, 16(1), 75; https://doi.org/10.3390/insects16010075 - 14 Jan 2025

Cited by 7 | Viewed by 5944

Abstract

Beekeeping is a crucial agricultural practice that significantly enhances environmental health and food production through effective pollination by honey bees. However, honey bees face numerous threats, including exotic parasites, large-scale transportation, and common agricultural practices that may increase the risk of parasite and [...] Read more.

Beekeeping is a crucial agricultural practice that significantly enhances environmental health and food production through effective pollination by honey bees. However, honey bees face numerous threats, including exotic parasites, large-scale transportation, and common agricultural practices that may increase the risk of parasite and pathogen transmission. A major threat is the Varroa destructor mite, which feeds on honey bee fat bodies and transmits viruses, leading to significant colony losses. Detecting the parasite and defining the intervention thresholds for effective treatment is a difficult and time-consuming task; different detection methods exist, but they are mainly based on human eye observations, resulting in low accuracy. This study introduces a digital portable scanner coupled with an AI algorithm (BeeVS) used to detect Varroa mites. The device works through image analysis of a sticky sheet previously placed under the beehive for some days, intercepting the Varroa mites that naturally fall. In this study, the scanner was tested for 17 weeks, receiving sheets from 5 beehives every week, and checking the accuracy, reliability, and speed of the method compared to conventional human visual inspection. The results highlighted the high repeatability of the measurements (R² ≥ 0.998) and the high accuracy of the BeeVS device; when at least 10 mites per sheet were present, the device showed a cumulative percentage error below 1%, compared to approximately 20% for human visual observation. Given its repeatability and reliability, the device can be considered a valid tool for beekeepers and scientists, offering the opportunity to monitor many beehives in a short time, unlike visual counting, which is done on a sample basis. Full article

(This article belongs to the Special Issue Advances on Conservation of Biodiversity, Monitoring Programs and Trend Assessment)

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13 pages, 3094 KB

Open AccessEditor’s ChoiceArticle

Fat Body Metabolome Revealed Glutamine Metabolism Pathway Involved in Prepupal Apis mellifera Responding to Cold Stress

by Xinjian Xu, Mingjie Cao, Chenyu Zhu, Lingqing Mo, Huajiao Huang, Jiaying Xie, Bingfeng Zhou, Shujing Zhou and Xiangjie Zhu

Insects 2025, 16(1), 37; https://doi.org/10.3390/insects16010037 - 2 Jan 2025

Cited by 5 | Viewed by 2700

Abstract

Thermal condition affects the development and growth of ectotherms. The stenothermic honeybee brood, particularly the prepupae, are sensitive to low rearing temperature. The fat body plays important roles in energy reserve and metabolism during the honeybee brood development. To date, the fat body [...] Read more.

Thermal condition affects the development and growth of ectotherms. The stenothermic honeybee brood, particularly the prepupae, are sensitive to low rearing temperature. The fat body plays important roles in energy reserve and metabolism during the honeybee brood development. To date, the fat body metabolic changes in prepupae responding to cold stress have not been completely understood. In this study, the ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS)-based non-target metabolome was analyzed between the cold-treated (CT, 20 °C, 36 h) and control (CK, 35 °C) fat body in prepupal honeybees. The fat body metabolomic data showed that the levels of 1860 and 254 metabolites were significantly increased and decreased, respectively, in cold-stressed prepupae. These altered metabolites, glutamine, glutamic acid, pyroglutamic acid, and oxidized glutathione, were significantly enriched into glutamine metabolism and glutathione metabolism pathways. Furthermore, the expression levels of glutamine metabolism-related genes, glutaminase (GLS), glutamate dehydrogenase (GDH), and gamma-glutamyl transferase (GGT-1 and GGT-7), were significantly decreased in cold-exposed prepupae compared with the control groups. Meanwhile, the oxidized glutathione (GSSG), but not the reduced glutathione (GSH) content, was increased in the cold-exposed group compared with controls. Collectively, our data revealed the fat body metabolomic changes in larva-to-pupa transition when exposed to cold stress. Our data provided new insights into stenothermic honeybee sensitivity to cold, characterized by perturbation of glutamine metabolism and oxidative stress. Full article

(This article belongs to the Special Issue Biology and Conservation of Honey Bees)

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15 pages, 1370 KB

Open AccessEditor’s ChoiceArticle

A First Step Towards Black Soldier Fly Larvae (Diptera: Stratiomyidae) Welfare by Considering Dietary Regimes (Part I)

by Arianna Cattaneo, Simona Belperio, Luca Sardi, Giovanna Martelli, Eleonora Nannoni, Marco Meneguz and Sihem Dabbou

Insects 2024, 15(10), 817; https://doi.org/10.3390/insects15100817 - 18 Oct 2024

Cited by 10 | Viewed by 5651

Abstract

The insect farming sector is expanding, but knowledge of insect welfare is still limited. This article aims to optimize the dietary regime for “black soldier fly” (Hermetia illucens L., BSF) larvae by applying a holistic view of welfare. Four diets were tested: [...] Read more.

The insect farming sector is expanding, but knowledge of insect welfare is still limited. This article aims to optimize the dietary regime for “black soldier fly” (Hermetia illucens L., BSF) larvae by applying a holistic view of welfare. Four diets were tested: control (CONTR, commercial laying hen feed), vegetable (VEG), omnivorous (OMN), and carnivorous (MEAT) diet, conducting experiments at a large (2000 larvae) and small scale (100 larvae). Rearing parameters were calculated including the growth rate, substrate reduction, efficiency of conversion of digested food, waste reduction index, and survival rate. Chemical analyses were conducted on BSF larvae and the residual frass. While the MEAT diet appears to be non-well-performing for the larvae, the VEG diet performed comparably to the control diet. Interestingly, the OMN diet demonstrated improved efficiency when evaluating the growth process at both scales. The chemical composition of larvae and frass highlighted the nutritional adequacy of the OMN diet, with the BSF larvae showing adequate protein and lipid content without nutrient catabolism or signs of discomfort. Applying the five freedoms of Brambell’s report as a welfare standard for animal rearing and evaluating performance as an indirect indicator of welfare, the OMN diet appears to promote larval welfare in rearing practices. Full article

(This article belongs to the Special Issue Insect Rearing: Reserve Forces with Commercial and Ecological Values)

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22 pages, 4376 KB

Open AccessEditor’s ChoiceArticle

Desert Ant (Melophorus bagoti) Dumpers Learn from Experience to Improve Waste Disposal and Show Spatial Fidelity

by Sudhakar Deeti and Ken Cheng

Insects 2024, 15(10), 814; https://doi.org/10.3390/insects15100814 - 16 Oct 2024

Cited by 5 | Viewed by 2073

Abstract

The Central Australian red honey-pot ant Melophorus bagoti maintains non-cryptic ground-nesting colonies in the semi-desert habitat, performing all the activities outside the nest during the hottest periods of summer days. These ants rely on path integration and view-based cues for navigation. They manage [...] Read more.

The Central Australian red honey-pot ant Melophorus bagoti maintains non-cryptic ground-nesting colonies in the semi-desert habitat, performing all the activities outside the nest during the hottest periods of summer days. These ants rely on path integration and view-based cues for navigation. They manage waste by taking out unwanted food, dead nestmates, and some other wastes, typically depositing such items at distances > 5 m from the nest entrance, a process called dumping. We found that over multiple runs, dumpers headed in the same general direction, showing sector fidelity. Experienced ants dumped waste more efficiently than naive ants. Naive individuals, lacking prior exposure to the outdoor environment around the nest, exhibited much scanning and meandering during waste disposal. In contrast, experienced ants dumped waste with straighter paths and a notable absence of scanning behaviour. Furthermore, experienced dumpers deposited waste at a greater distance from the nest compared to their naive counterparts. We also investigated the navigational knowledge of naive and experienced dumpers by displacing them 2 m away from the nest. Naive dumpers were not oriented towards the nest in their initial trajectory at any of the 2 m test locations, whereas experienced dumpers were oriented towards the nest at all test locations. Naive dumpers were nest-oriented as a group, however, at the test location nearest to where they dumped their waste. These differences suggest that in red honey ants, learning supports waste disposal, with dumping being refined through experience. Dumpers gain greater spatial knowledge through repeated runs outside the nest, contributing to successful homing behaviour. Full article

(This article belongs to the Section Social Insects and Apiculture)

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14 pages, 4726 KB

Open AccessEditor’s ChoiceArticle

Exposure to Cyantraniliprole Adversely Impacts Fitness of Harmonia axyridis: Acute Toxicity and Sublethal Effects on Development, Fecundity and Antioxidant Responses

by Tianshu Zhang, Yongda Yuan, Haiyuan Teng, Dongsheng Wang and Haotian Gu

Insects 2024, 15(10), 773; https://doi.org/10.3390/insects15100773 - 6 Oct 2024

Cited by 11 | Viewed by 3008

Abstract

Extensive utilization of pesticides and their persistent residues inadvertently pose threats to the effectiveness and fitness of biocontrol agents in agroecosystems. However, these ecological consequences are generally disregarded when executing integrated pest management strategies (IPM). Cyantraniliprole (CNAP) serves as a wide-spectrum diamide insecticide [...] Read more.

Extensive utilization of pesticides and their persistent residues inadvertently pose threats to the effectiveness and fitness of biocontrol agents in agroecosystems. However, these ecological consequences are generally disregarded when executing integrated pest management strategies (IPM). Cyantraniliprole (CNAP) serves as a wide-spectrum diamide insecticide and its sublethal effects have been well characterized on multiple insect pests, whereas its impacts on beneficial natural enemies remain unfathomed. Herein we exposed Harmonia axyridis, a predacious generalist, to lethal and sublethal concentrations of CNAP via dipping treatment (egg stage) and topical applications (1st-instar stage + adult stage). The acute toxicity tests revealed that LC₅₀ of CNAP were 90.11, 86.11 and 240.50 mg/L against embryos, 1st instar nymphs and female adults, respectively, with safety factors ranging from 1.14 to 5.34, suggesting its medium toxicity for H. axyridis and larval stage was the most susceptible. The embryonic, larval and pupal durations of coccinellids ecdysed from CNAP-treated eggs and 1st instars were all elongated under sublethal concentrations, of which LC₃₀ triggered more pronounced and significant retardations relative to control. Besides, exposed coccinellids displayed substantially diminished pupal mass and pupation rate, most notably for insects molted from the 1st-instar stage upon CNAP sublethal treatments. With respect to reproductive performance, LC₁₀ and LC₃₀ of CNAP all significantly suppressed female fecundity, as evidenced by reduced vitellin content, a prolonged pre-oviposition period (POP), mitigated laid eggs and the egg hatching rate. Specifically, there existed positive correlations between vitellin level (Vn) and number of eggs deposited by per female, indicative of CNAP affecting fecundity by regulation of Vn. In addition, the antioxidant system was also profoundly disrupted by CNAP, with compromised POD activity at different concentrations over time and induced hormesis of SOD/CAT activities post LC₁₀ exposure. Activities of SOD and TAC were enhanced to exert protective functions during the first 48 h, while defense collapsed at 72 h following LC₃₀ treatments that depleted all enzymatic activities. We speculated that fitness trade-offs may occur between reproductive capacity and antioxidant defenses to sustain physiological homeostasis in response to CNAP stress. Collectively, this study evaluated the ecological risk of CNAP and unmasked its adverse implications for overall fitness of H. axyridis, which highlighted rational application of agrochemicals to conserve biocontrol agents when implementing IPM strategies for sustainable pest control. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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15 pages, 2274 KB

Open AccessEditor’s ChoiceArticle

Mitigating the Threat of Invasive Mosquito Species Expansion: A Comprehensive Entomological Surveillance Study on Kastellorizo, a Remote Greek Island

by Marina Bisia, Georgios Balatsos, Stavroula Beleri, Nikolaos Tegos, Evangelia Zavitsanou, Shannon L. LaDeau, Vasilis Sotiroudas, Eleni Patsoula and Antonios Michaelakis

Insects 2024, 15(9), 724; https://doi.org/10.3390/insects15090724 - 20 Sep 2024

Cited by 5 | Viewed by 3646

Abstract

The expansion of the tiger mosquito, a vector that can transmit diseases such as dengue, chikungunya, and Zika virus, poses a growing threat to global health. This study focuses on the entomological surveillance of Kastellorizo, a remote Greek island affected by its expansion. [...] Read more.

The expansion of the tiger mosquito, a vector that can transmit diseases such as dengue, chikungunya, and Zika virus, poses a growing threat to global health. This study focuses on the entomological surveillance of Kastellorizo, a remote Greek island affected by its expansion. This research employs a multifaceted approach, combining KAP survey (knowledge, attitude, practices), mosquito collection using adult traps and human landing catches, and morphological and molecular identification methods. Results from questionnaires reveal community awareness and preparedness gaps, emphasizing the need for targeted education. Mosquito collections confirm the presence of the Aedes albopictus, Aedes cretinus, and Culex pipiens mosquitoes, highlighting the importance of surveillance. This study underscores the significance of community engagement in entomological efforts and proposes a citizen science initiative for sustained monitoring. Overall, this research provides essential insights for developing effective mosquito control programs in remote island settings, thereby emphasizing the importance of adopting a One Health approach to mitigate the spread of vector-borne diseases. Full article

(This article belongs to the Special Issue Biology, Ecology and Management of Mosquitoes Affecting Humans and Animals)

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15 pages, 975 KB

Open AccessEditor’s ChoiceArticle

Monitoring and Detection of Insecticide Resistance in Spodoptera frugiperda (Lepidoptera: Noctuidae): Evidence for Field-Evolved Resistance in Egypt

by Moataz A. M. Moustafa, Nourhan A. El-Said, Nawal AbdulAziz Alfuhaid, Fatma M. A. Abo-Elinin, Radwa M. B. Mohamed and Ahmed A. A. Aioub

Insects 2024, 15(9), 705; https://doi.org/10.3390/insects15090705 - 16 Sep 2024

Cited by 38 | Viewed by 6083

Abstract

Spodoptera frugiperda (J.E. Smith) (Noctuidae: Lepidoptera) is a notable insect pest that invades major cereal crops, causing significant damage and loss. Resistances of 2nd instar larvae of two Egyptian field populations of S. frugiperda, collected from the Fayoum and Giza governments, were [...] Read more.

Spodoptera frugiperda (J.E. Smith) (Noctuidae: Lepidoptera) is a notable insect pest that invades major cereal crops, causing significant damage and loss. Resistances of 2nd instar larvae of two Egyptian field populations of S. frugiperda, collected from the Fayoum and Giza governments, were measured against eight insecticides, including traditional insecticides (profenofos and cypermethrin), bio-insecticides (emamectin benzoate, spinosad, and Bacillus thuringiensis), and insect growth regulators (IGRs) (lufenuron, diflubenzuron, and methoxyfenozide). In addition, the synergistic effects of three synergists (Piperonyl butoxide (PBO), diethyl maleate (DEM), and triphenyl phosphate (TPP) were assessed, and the activities of detoxification enzymes (acetylcholine esterase (AChE), cytochrome P-450 (CYP-450), carboxylesterase (CarE), and glutathione-s-transferase (GST) were also determined. Resistance surveillance revealed that the Fayoum field population showed moderate resistance to cypermethrin (RR = 5.75-fold), followed by spinosad (RR = 2.62-fold), and lufenuron (2.01-fold). On the other hand, the Giza population exhibited significant resistance to cypermethrin only (RR = 3.65-fold). Our results revealed that emamectin benzoate was the most effective insecticide, with an LC₅₀ value of 0.003 mg/L for the Fayoum population and 0.001 mg/L for the Giza population, compared to the susceptible strain (0.005 mg/L). Among the biological insecticides, Bacillus thuringiensis was the least toxic insecticide of all the tested strains. Synergism assays indicated that DEM and TPP had the most synergistic effect on spinosad (SR = 8.00-fold for both), followed by PBO (SR = 5.71-fold) for the Fayoum population, compared with spinosad alone. The assay of detoxification enzymes showed that GST activity significantly (p < 0.05) increased in the two field strains compared to the susceptible strain. However, no significant changes were observed among the tested strains in CYP-450, CarE, or AChE. The findings of this study provide substantial insights into tracking and managing the development of insecticide resistance in S. frugiperda in Egypt. Full article

(This article belongs to the Special Issue Chemical Toxicology and Insecticide Resistance on Insect Pests)

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14 pages, 4539 KB

Open AccessEditor’s ChoiceArticle

The Effect of Soil Type and Moisture on the Development of Forensically Important Megaselia scalaris and Dohrniphora cornuta (Diptera: Phoridae)

by Wei Han, Dianxing Feng and Yanan Tang

Insects 2024, 15(9), 666; https://doi.org/10.3390/insects15090666 - 1 Sep 2024

Cited by 5 | Viewed by 2493

Abstract

Necrophagous phorid flies are common insects found on buried corpses, and their developmental data play a crucial role in estimating the post-burial interval (PBI). This study aimed to investigate the effects of soil type and moisture content on some life cycle parameters of [...] Read more.

Necrophagous phorid flies are common insects found on buried corpses, and their developmental data play a crucial role in estimating the post-burial interval (PBI). This study aimed to investigate the effects of soil type and moisture content on some life cycle parameters of two forensically important insects, Megaselia scalaris (Loew, 1866) and Dohrniphora cornuta (Bigot, 1857) (Diptera: Phoridae). Larval and pupal survival, development time, and larval body length of M. scalaris and D. cornuta were observed in three different soil types (loamy sand, sandy loam A, and sandy loam B) with six moisture contents (0%, 20%, 40%, 60%, 80%, and 100%). The results indicated that soil types, soil moisture, and their interaction significantly influenced the growth and development of both species, with moisture being the most influential factor. In each soil, 20% and 40% moisture contents were more suitable for their growth and development. Both the development time and maximum larval body length were significantly different among soil types and moisture contents. The larval period of both species lasted the longest in all soils with 0% moisture content. Additionally, a regression analysis of the relationship between larval body length and development time was performed at different moisture contents in three soils. This study expanded our knowledge of the factors that influence the development of necrophagous insects and provided some reference data for applications of M. scalaris and D. cornuta in PBI estimation. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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27 pages, 11103 KB

Open AccessEditor’s ChoiceArticle

Resolving the Taxonomy of Mountain Syrphidae (Diptera) in the Iberian Peninsula: The Species Group of Cheilosia melanura Becker, 1894

by Iván Ballester-Torres, Zorica Nedeljković, Pablo Aguado-Aranda, Ante Vujić, María Ángeles Marcos-García and Antonio Ricarte

Insects 2024, 15(9), 640; https://doi.org/10.3390/insects15090640 - 26 Aug 2024

Cited by 3 | Viewed by 3711

Abstract

The largest genus of Palaearctic Syrphidae, Cheilosia Meigen, 1822 (Syrphidae: Rhingiini), is currently under revision in the Ibero-Balearic region (Iberian Peninsula + Balearic Islands). Prior to this study, various species groups with putative phylogenetic support were defined for this genus of complex taxonomy. [...] Read more.

The largest genus of Palaearctic Syrphidae, Cheilosia Meigen, 1822 (Syrphidae: Rhingiini), is currently under revision in the Ibero-Balearic region (Iberian Peninsula + Balearic Islands). Prior to this study, various species groups with putative phylogenetic support were defined for this genus of complex taxonomy. The group of Cheilosia melanura Becker, 1894 includes species distributed all over Europe, with some of these species being similar each other in both morphology and genetics. After recent fieldwork in different Iberian localities and consultation of entomological collections, a new species from Sierra Nevada (Granada, Spain) was uncovered, described, and illustrated. Data on diagnostic characters, intraspecific variability, and adult biology were also provided. Maximum likelihood analyses of the fragment “C” of the 5′ end of the cytochrome c oxydase subunit I (COI-5′) and complete COI-5′ were performed to explore and support morphological species concepts within the group. The Spanish-endemic Cheilosia andalusiaca Torp Pedersen, 1971 is recognised here to be part of the C. melanura group based both on morphological and molecular evidence. Cheilosia carbonaria Egger, 1860 and Cheilosia cynocephala Loew, 1840 from the Iberian Peninsula are reported for the first time based on specimens originating in the Spanish Pyrenees. An identification key for the Iberian species of the C. melanura group is provided. Full article

(This article belongs to the Section Insect Systematics, Phylogeny and Evolution)

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13 pages, 2035 KB

Open AccessEditor’s ChoiceArticle

Exploring Bemisia tabaci Middle East–Asia Minor I and Mediterranean Cryptic Species Relationship with Cowpea Mild Mottle Virus and Their Dynamics in Soybean Fields

by Felipe Barreto da Silva, Rodrigo de Sarandy Raposo, Sarah Forlani de Campos, Juliana Uzan, Julio Massaharu Marubayashi, Marcos Roberto Ribeiro-Junior, Angélica Maria Nogueira, Caroline da Cruz Martines, Vinicius Henrique Bello, Cristiane Müller, Maria Márcia Pereira Sartori and Renate Krause-Sakate

Insects 2024, 15(8), 624; https://doi.org/10.3390/insects15080624 - 19 Aug 2024

Cited by 6 | Viewed by 3037

Abstract

Cowpea mild mottle virus (CPMMV, genus Carlavirus, family Betaflexividae) is an economically important virus infecting soybeans in Brazil, where it was initially identified in 1983. CPMMV is transmitted by the whitefly, Bemisia tabaci, and occasionally by seeds. Over the last [...] Read more.

Cowpea mild mottle virus (CPMMV, genus Carlavirus, family Betaflexividae) is an economically important virus infecting soybeans in Brazil, where it was initially identified in 1983. CPMMV is transmitted by the whitefly, Bemisia tabaci, and occasionally by seeds. Over the last three decades, the most invasive B. tabaci Middle East–Asia Minor 1 (MEAM1), and lately the Mediterranean (MED) cryptic species, have replaced the indigenous species in Brazil, with MEAM1 being predominant. In this study, we investigated the transmission properties of CPMMV by MEAM1 and MED, and their distribution in major soybean-growing areas in São Paulo State. Our results from transmission assays with a single insect revealed that MED is a more efficient vector compared to MEAM1, transmitting the virus within a two-minute inoculation access period. B. tabaci MEAM1 is still the predominant whitefly species in São Paulo State, but MED was also identified in different places, mainly in mixed infestations with MEAM1. Some areas transitioned to a predominance of MED over the three years, while others, where MED had previously been detected, showed a reduction in the insects during the same period. Understanding the transmission dynamics of CPMMV and the distribution of its vectors is crucial for implementing effective management strategies to control the virus spread and protect soybean crops. Further research into the mechanisms driving the shifts in whitefly species dominance and CPMMV distribution will be essential for sustaining soybean production in Brazil. Full article

(This article belongs to the Special Issue Insects Vectors of Phytopathogenic Agents: Biology, Host-Plant Interactions, and Management)

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11 pages, 1714 KB

Open AccessEditor’s ChoiceArticle

Temperature-Dependent Oviposition Models for Monochamus saltuarius (Coleoptera: Cerambycidae)

by Hyoseok Lee, Jong-Kook Jung, Youngwoo Nam and Sang-Hyun Koh

Insects 2024, 15(8), 597; https://doi.org/10.3390/insects15080597 - 6 Aug 2024

Cited by 2 | Viewed by 2298

Abstract

Monochamus saltuarius Gebler is a serious insect pest in Europe and East Asia regions, including Portugal, Spain, China, Japan, and Korea. It transfers the pine wood nematode Bursaphelenchus xylophilus to conifer trees, resulting in pine wilt disease (PWD). As temperature is a key [...] Read more.

Monochamus saltuarius Gebler is a serious insect pest in Europe and East Asia regions, including Portugal, Spain, China, Japan, and Korea. It transfers the pine wood nematode Bursaphelenchus xylophilus to conifer trees, resulting in pine wilt disease (PWD). As temperature is a key factor influencing insect population dynamics, temperature-dependent models describing M. saltuarius oviposition could estimate population growth potential and evaluate outbreak risks. In this study, the longevity and fecundity of M. saltuarius females were measured under constant temperature conditions ranging from 20 to 32 °C, and temperature-dependent models were constructed. The longevity of M. saltuarius females ranged from 83.36 days to 22.92 days, with a total fecundity of 141 eggs and 52.77 eggs at 20 °C and 32 °C, respectively. To describe oviposition, we used a single-phase simulation describing oviposition as a single model and a two-phase simulation describing sexual maturation and oviposition as two separate models. These models effectively described M. saltuarius oviposition (r² > 0.96) under constant temperature conditions, with the two-phase simulation demonstrating greater accuracy overall. Such models could facilitate assessments of PWD risks. The modeling framework of this study shows potential for predicting threats from various forestry and agricultural pests. Full article

(This article belongs to the Section Insect Pest and Vector Management)

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18 pages, 2737 KB

Open AccessEditor’s ChoiceArticle

Chlorantraniliprole Enhances Cellular Immunity in Larvae of Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae)

by Qingyan Liu, Xiaoyue Deng, Liuhong Wang, Wenqi Xie, Huilai Zhang, Qing Li, Qunfang Yang and Chunxian Jiang

Insects 2024, 15(8), 586; https://doi.org/10.3390/insects15080586 - 1 Aug 2024

Cited by 4 | Viewed by 2883

Abstract

The innate immunity of insects encompasses cellular and humoral defense mechanisms and constitutes the primary defense against invading microbial pathogens. Cellular immunity (phagocytosis, nodulation, and encapsulation) is primarily mediated by hemocytes. Plasmatocytes and granulocytes play an important role and require changes in the [...] Read more.

The innate immunity of insects encompasses cellular and humoral defense mechanisms and constitutes the primary defense against invading microbial pathogens. Cellular immunity (phagocytosis, nodulation, and encapsulation) is primarily mediated by hemocytes. Plasmatocytes and granulocytes play an important role and require changes in the cytoskeletons of hemocytes. However, research investigating the immunological impacts of insecticides on the fall armyworm (FAW), Spodoptera frugiperda, remains scarce. Therefore, we conducted a study to investigate the effects of chlorantraniliprole exposure on cellular immunity in FAW larvae. Our findings revealed the presence of five types of hemocytes in the larvae: prohemocytes, plasmatocytes, granulocytes, oenocytoids, and spherulocytes. The LD₁₀, LD₂₀, and LD₃₀ of chlorantraniliprole affected both the morphology and total count of some hemocytes in the larvae. Moreover, larvae exposed to chlorantraniliprole showed increased phagocytosis, nodulation, and encapsulation. To determine the mechanism of the enhanced cellular immunity, we studied plasmatocytes in the spread state and the cytoskeleton in hemocytes. It was found that the spreading ratio of plasmatocytes and the areas of the cytoskeletons in hemocytes were increased after chlorantraniliprole treatment. These results suggest that exposure to chlorantraniliprole results in an enhanced immune response function in FAW larvae, which may be mediated by cytoskeletal changes and plasmatocyte spreading. Consequently, this study provides valuable insights into the cellular immune response of FAW larvae to insecticide exposure. Full article

(This article belongs to the Special Issue Research on Insect Interactions with Symbionts and Pathogens)

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24 pages, 3912 KB

Open AccessEditor’s ChoiceArticle

Cryptic Taxa Revealed through Combined Analysis of Chromosomes and DNA Barcodes: The Polyommatus ripartii Species Complex in Armenia and NW Iran

by Vladimir A. Lukhtanov and Alexander V. Dantchenko

Insects 2024, 15(7), 545; https://doi.org/10.3390/insects15070545 - 19 Jul 2024

Cited by 4 | Viewed by 2603

Abstract

The detection of cryptic species in complexes that have undergone recent speciation is often difficult, since many standard nuclear markers have not yet accumulated differences between closely related taxa, and differences in mitochondrial markers can be leveled out due to mitochondrial introgressions. In [...] Read more.

The detection of cryptic species in complexes that have undergone recent speciation is often difficult, since many standard nuclear markers have not yet accumulated differences between closely related taxa, and differences in mitochondrial markers can be leveled out due to mitochondrial introgressions. In these cases, the use of derived chromosomal characters such as non-ancestral chromosomal numbers and/or unusual karyotype features may be a solution to the species delimitation problem. However, non-ancestral but similar karyotypes may arise secondarily as a result of homoplastic evolution, and their interpretation as homologies may lead to incorrect taxonomic conclusions. In our study, we show that the combined use of mitochondrial DNA barcodes and karyotypes helps to solve this problem and identifies cryptic species in situations where each of these markers does not work individually. Using this approach, we show that the fauna of Armenia and adjacent Iran includes the following cryptic taxa of the Polyommatus ripartii species complex (haploid chromosome number, n in parentheses): P. ripartii paralcestis (n = 90), P. ripartii kalashiani, subsp. nov (n close to 90), P. emmeli, sp. nov. (n = 77–79), P. keleybaricus, sp. nov. (n = 86), P. demavendi belovi (n = 73–75), P. demavendi antonius, subsp. nov. (n = 71–73), P. admetus anatoliensis (n = 79) and P. eriwanensis (n = 29–34). Polyommatus admetus yeranyani is synonymized with P. admetus anatoliensis. Full article

(This article belongs to the Section Insect Systematics, Phylogeny and Evolution)

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