Insects

17 pages, 1595 KiB

Open AccessArticle

Enhancing the Survival of Ichneumonid Parasitoid Campoletis chlorideae (Hymenoptera: Ichneumonidae) by Utilizing Haserpin-e Protein to Effectively Manage Lepidopteran Pests

by Liuming Huo, Xue Yao, Ningbo Zhang, Shengyi Wang, Sufen Bai, Yanmei Wang, Jizhen Wei and Shiheng An

Insects 2025, 16(5), 474; https://doi.org/10.3390/insects16050474 (registering DOI) - 29 Apr 2025

Abstract

The ichneumonid parasitoid Campoletis chlorideae is an important natural enemy of lepidopteran pests in different agro-ecosystems, specifically targeting early larvae (second- and third-instar). Enhancing the survival of C. chlorideae, especially within hosts, remains a significant technical challenge for large-scale indoor reproduction. This study [...] Read more.

The ichneumonid parasitoid Campoletis chlorideae is an important natural enemy of lepidopteran pests in different agro-ecosystems, specifically targeting early larvae (second- and third-instar). Enhancing the survival of C. chlorideae, especially within hosts, remains a significant technical challenge for large-scale indoor reproduction. This study investigates the use of endogenous serpin-e protein, derived from the host Helicoverpa armigera (Haserpin-e), to improve the survival rate of C. chlorideae in indoor reproduction. The results demonstrated that Haserpin-e protein significantly enhanced cocoon production in C. chlorideae, with no observable adverse effects on the life history traits of both F0 and F1 generations of C. chlorideae. By investigating the mechanism underlying cocoon formation promotion, it was found that Haserpin-e protein reduced the encapsulation, inhibited melanization, as well as suppressed the expression of antimicrobial proteins (AMPs) in H. armigera. This study provides novel insights into improving the survival of C. chlorideae by inhibiting host immune responses through the application of its endogenous Haserpin-e protein during large-scale indoor reproduction efforts. Additionally, this research further elucidates the multifaceted functionality of Haserpin-e proteins by demonstrating their role in regulating innate immune processes in H. armigera, including negatively regulating encapsulation, melanization, and AMP expression. Full article

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

14 pages, 2210 KiB

Open AccessArticle

Nesting Preferences of Osmia orientalis (Hymenoptera: Megachilidae) in the Field and Its Potential as a Strawberry Pollinator in Greenhouses

by Ikuo Kandori, Yudai Ogata and Tomoyuki Yokoi

Insects 2025, 16(5), 473; https://doi.org/10.3390/insects16050473 - 29 Apr 2025

Abstract

The western honeybee, Apis mellifera, is used worldwide as a pollinator of crops such as strawberries; however, it is an introduced species in Japan. The mason bee, Osmia orientalis Benoist (Hymenoptera: Megachilidae), is native to Japan, where it nests in empty snail [...] Read more.

The western honeybee, Apis mellifera, is used worldwide as a pollinator of crops such as strawberries; however, it is an introduced species in Japan. The mason bee, Osmia orientalis Benoist (Hymenoptera: Megachilidae), is native to Japan, where it nests in empty snail shells and has potential as a crop pollinator. We conducted three experiments to collect information on the nesting habits and potential agricultural use of this species as a pollinator of greenhouse-grown strawberries. Our first experiment investigated the bees’ nesting preferences in the field by placing the empty shells of four snail species, Euhadra amaliae, Satsuma japonica, Sinotaia quadrata histrica, and Helix lucorum, in six different environments. The nesting rate was significantly higher in medium-sized, empty E. amaliae shells. Regarding the surrounding environment, O. orientalis preferred tall and short grasslands to bare ground and forest interiors. Our second experiment investigated per-visit strawberry flower pollination efficiency. The results indicated that the efficiency of O. orientalis was equal to or greater than that of A. mellifera. In our third experiment, as a replacement for empty snail shells, which are scarce natural sources, four types of plastic artificial shells were created and placed inside a greenhouse together with E. amaliae shells. The nesting rates in three types of artificial shells were nearly identical to those in E. amaliae shells, implying that these artificial shells may be effective nesting materials. Although many questions remain before practical application, our results indicate the potential for using O. orientalis as a pollinator of greenhouse-grown strawberries. Full article

(This article belongs to the Collection Insects on Pollination Ecology)

18 pages, 1518 KiB

Open AccessArticle

Adding Fruit Fermentation Liquid Improves the Efficiency of the Black Soldier Fly in Converting Chicken Manure and Reshapes the Structure of Its Intestinal Microbial Community

by Lifei Chen, Guiying Wang, Hanhan Song, Qi Yang, Jiani Fu, Jiale Liu, Haoyang Sun, Yuxi Wang, Qile Tian, Yuting Sun, Lei Sun, Hao Xin, Zuyin Xiao, Guoliang Wang, Zixuan Zhang, Yinling Zhao, Hongyan Yang and Lusheng Li

Insects 2025, 16(5), 472; https://doi.org/10.3390/insects16050472 - 29 Apr 2025

Abstract

This study evaluated how fruit fermentation liquid (FFL) enhances the conversion of chicken manure by black soldier fly larvae (BSFL) and modulates their gut microbiota. Three groups were tested: control (A: 300 g manure + 50 g water), low-dose FFL (B: 300 g [...] Read more.

This study evaluated how fruit fermentation liquid (FFL) enhances the conversion of chicken manure by black soldier fly larvae (BSFL) and modulates their gut microbiota. Three groups were tested: control (A: 300 g manure + 50 g water), low-dose FFL (B: 300 g manure + 25 g FFL + 25 g water), and high-dose FFL (C: 300 g manure + 50 g FFL). The results show that the dry matter conversion rate significantly increased by 9.5% (p < 0.05), while the feed-to-larvae ratio was reduced by 1.02 (p < 0.01) in group C. NH₃ emissions in group C decreased by 24.48 mg·kg⁻¹·DM (dry matter substrate) day⁻¹ (24.48 mg per kilogram of dry matter substrate per day) (p < 0.01), with suppressed H₂S release. Gut microbiota analysis revealed that FFL reduced the abundance of Proteobacteria (6.07% decrease in group C) while enriching Actinobacteriota (4.68% increase) and beneficial genera (Corynebacterium, Gallicola). Substrate microbial diversity in group C improved, with Proteobacteria and Firmicutes increasing by 11.07% and 4.83%, respectively, and pathogenic Sphingobacteriaceae declining by 21.16% by day 7. FFL likely introduced organic acids and nutrients, enhancing larval digestion and nutrient absorption while inhibiting the production of harmful gases. These findings demonstrate that FFL optimizes BSFL-driven waste conversion efficiency through modulation of the microbiota, offering a sustainable strategy for organic waste management and contributing to circular agricultural systems. Full article

(This article belongs to the Section Role of Insects in Human Society)

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9 pages, 1796 KiB

Open AccessCommunication

Hydrogen Stable Isotopes Indicate Reverse Migration of Fall Armyworm in North America

by Eduardo S. Calixto and Silvana V. Paula-Moraes

Insects 2025, 16(5), 471; https://doi.org/10.3390/insects16050471 - 29 Apr 2025

Abstract

Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae), is a major pest in the U.S. and has spread globally, causing severe agricultural losses in different countries. Due to its high mobility and potential for long-distance dispersal, understanding FAW migration is [...] Read more.

Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae), is a major pest in the U.S. and has spread globally, causing severe agricultural losses in different countries. Due to its high mobility and potential for long-distance dispersal, understanding FAW migration is a key tool for forecasting outbreaks and implementing timely management measures. Recent studies using stable hydrogen isotopes indicated reverse (southward) migration of Helicoverpa zea Boddie (Lepidoptera: Noctuidae). Here, we tested the reverse migration hypothesis for FAW in North America. Estimation of the hydrogen isotopic ratio on 324 samples collected in Florida, an intermixing zone at the edge of the continental U.S., indicated evidence of reverse migration in samples of FAW moths. They showed a high probability of origin from the U.S. Corn Belt, with a greater probability of origin in Nebraska, South Dakota, Minnesota, Kansas and Wisconsin. This southward movement provides new insights into the risk of spreading pesticide resistance alleles in this species to southern regions and contributes to the improvement of integrated pest management and insect resistance management programs. Full article

(This article belongs to the Special Issue Corn Insect Pests: From Biology to Control Technology)

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16 pages, 5233 KiB

Open AccessArticle

Effects of Colony Breeding System and Nest Architecture on Soil Microbiome and Fertility in the Fungus-Growing Termite Macrotermes barneyi Light

by Jiachang Zhou, Wenquan Qin, Yang Zeng, Xin Huang, Jing Yuan, Yuting Yin, Paike Xu, Xiaohong Fan, Runfeng Zhang, Ganghua Li and Yinqi Zhang

Insects 2025, 16(5), 470; https://doi.org/10.3390/insects16050470 - 29 Apr 2025

Abstract

Macrotermes barneyi is a typical fungus-growing termite that forms both monogynous (single queen) and polygynous (multiple queen) colonies in nature. This species influences the local soil fertility in part by redistributing nutrients across the landscape in its habitats. However, how the colony structure [...] Read more.

Macrotermes barneyi is a typical fungus-growing termite that forms both monogynous (single queen) and polygynous (multiple queen) colonies in nature. This species influences the local soil fertility in part by redistributing nutrients across the landscape in its habitats. However, how the colony structure of M. barneyi affects nutrient cycling and microbial communities within the nest is not well understood. In this study, we compared the physicochemical properties and microbial communities across nest parts between monogynous and polygynous colonies of M. barneyi. Our results showed that the fungus garden is the most nutrient-rich part of the nest, with higher soil moisture, organic matter, ammonium nitrogen, nitrate nitrogen, available sulfur, available potassium, available silicon, and available boron than other nest parts. Notably, the fungus garden in monogynous colonies had higher nitrate nitrogen, available sulfur, and available silicon than those in the polygynous colonies. The microbial α-diversity in the fungus garden was lower than that in other parts of the nest. β-diversity analysis revealed a clear separation of microbial communities between monogynous and polygynous colonies across nest parts. Furthermore, the relative abundance of functional genes associated with “cell cycle control, cell division, and chromosome partitioning” was higher in the fungus garden of polygynous colonies compared to monogynous colonies. Our results suggest that the fungus garden plays a crucial role in maintaining colony stability in M. barneyi colonies. The rapid depletion of nutrients in the fungus garden to sustain the larger population in polygynous colonies likely influences microbial community dynamics and nutrient cycling. Full article

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

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16 pages, 7129 KiB

Open AccessArticle

by Luyu Hou, Jinxin Wu, Die Liu, Haoran Xu, Hongbo Yao, Yiwen Liang, Qingyou Xia, Ping Lin and Guanwang Shen

Insects 2025, 16(5), 469; https://doi.org/10.3390/insects16050469 - 29 Apr 2025

Abstract

Estrogen-related receptors (ERRs) are important transcription factors within the nuclear receptor family that regulate cellular energy storage and consumption by binding to estrogen-related receptor response elements (ERREs) on gene promoters. While ERRs’ role in vertebrates is well-studied, their molecular mechanisms in insect metabolism [...] Read more.

Estrogen-related receptors (ERRs) are important transcription factors within the nuclear receptor family that regulate cellular energy storage and consumption by binding to estrogen-related receptor response elements (ERREs) on gene promoters. While ERRs’ role in vertebrates is well-studied, their molecular mechanisms in insect metabolism and development remain unclear. This study systematically summarizes the functions of ERRs in insects, focusing on silkworms by analyzing gene functions and comparing databases. ERRE-like elements were identified in the 2000 bp upstream promoter regions of 69 metabolism-related silkworm genes. Furthermore, electrophoretic mobility shift assays (EMSAs) revealed that ERREs within the promoters of 15 genes related to sugar, fat, and protein metabolism specifically bind to ERR. Notably, an ERRE in the promoter of the trehalose transporter 1 gene (BmTret1), crucial for trehalose homeostasis in insect hemolymph, exhibited significantly enhanced activity in ERR-overexpressing cells. These findings suggest that ERR is a potential regulatory factor in silkworm metabolism and refine its metabolic regulatory network. This study highlights the broader and more critical role of ERR in insects than that previously recognized, contributing to a deeper understanding of insect metabolism and its potential applications in related fields. Full article

(This article belongs to the Special Issue Genomics and Molecular Biology in Silkworm)

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12 pages, 1702 KiB

Open AccessArticle

Use of Sugar Dispensers at Lower Density Can Decrease Mealybug (Hemiptera: Pseudococcidae) Infestation in Vineyards by Disrupting Ants

by Giovanni Burgio, Serena Magagnoli, Luca Casoli, Marco Profeta, Donato Antonio Grasso, Enrico Schifani, Daniele Giannetti and Martina Parrilli

Insects 2025, 16(5), 468; https://doi.org/10.3390/insects16050468 - 29 Apr 2025

Abstract

Vineyard mealybugs (Hemiptera: Pseudococcidae) are economic pests in vineyards, demanding integrated control strategies. Several ant species can facilitate mealybug infestation by protecting them from natural enemies in a mutualistic relationship known as trophobiosis. In the frame of an ant management system, the provision [...] Read more.

Vineyard mealybugs (Hemiptera: Pseudococcidae) are economic pests in vineyards, demanding integrated control strategies. Several ant species can facilitate mealybug infestation by protecting them from natural enemies in a mutualistic relationship known as trophobiosis. In the frame of an ant management system, the provision of sugary liquid has proved worldwide to improve mealybug control. In the present study, a field trial was carried out within an important vineyard cultivation area of northern Italy with the aim of testing a lower density (80/ha) of sugar dispenser to facilitate the practicality of this method. The sugar dispensers tested, along with predators and parasitoid release, were effective in reducing mealybug infestations by 22% and resulted in a double increase in larval density of the predator Cryptolaemus mountrouzieri Mulsant. Mealybug parasitism was in general high, but it was not improved by sugar dispensers at this density. Our field validation confirms the importance of ants in mealybug infestation dynamics, and the benefits of ant management in the context of integrated strategies against mealybugs. Full article

(This article belongs to the Special Issue Advances in Research on Parasitoids for Biological Control of Agricultural Pests)

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17 pages, 4143 KiB

Open AccessArticle

Repellent Activity of DEET and Biont-Based Mosquito Repellents in the Chinese Market Against the Asian Long-Horned Tick, Haemaphysalis longicornis

by Weiqing Zheng, Yuyang Zhang, Jingzhi Huang, Qinglu Wu, Jintong Fu, Yongwei Wen, Siyu Fang, Xiaoyan Yang and Qianfeng Xia

Insects 2025, 16(5), 467; https://doi.org/10.3390/insects16050467 - 29 Apr 2025

Abstract

To investigate the repellent efficacy of commercially available mosquito repellents in China against Haemaphysalis longicornis, four representative DEET-based repellents and biont-derived repellents were selected. This study utilized a modified circular filter paper method repellent testing device to establish an evaluation system for [...] Read more.

To investigate the repellent efficacy of commercially available mosquito repellents in China against Haemaphysalis longicornis, four representative DEET-based repellents and biont-derived repellents were selected. This study utilized a modified circular filter paper method repellent testing device to establish an evaluation system for assessing the repellent effects of each product against three developmental stages of H. longicornis: larvae, nymphs, and adults. In our study, for DEET-based repellents, Johnson demonstrated the highest repellency against larvae within 1 h, with an average repellency rate exceeding 80.14%. Yamei and Johnson exhibited repellency rates more than 91.11% for nymphs within 1 h, surpassing the other two DEET products. Repellency rates of Longliqi and Xiaohuanxiong fluctuated between 80.95% and 100% at different time points. Yamei, Longliqi, and Johnson achieved 100% repellency to adults within 1 h, while Xiaohuanxiong showed slightly lower efficacy. The four biont-derived repellents showed significant variations in efficacy: larval-stage repellency ranged from 14.29% to 88.89%, nymphal-stage repellency from 57.89% to 100%, and adult-stage repellency from 50% to 79.49%. CaliforniaBaby exhibited the highest efficacy, comparable or superior to DEET-based products, whereas Longhu demonstrated the weakest repellency and poor persistence. We further conducted a persistence test for CaliforniaBaby and found that it maintained >75% repellency against H. longicornis for 6 h. This study provides scientific evidence for selecting tick repellents in practice, offers guidance for purchasing commercial biont-derived tick repellents, and serves as a reference for developing safer, more effective tick repellents. Full article

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

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20 pages, 3055 KiB

Open AccessArticle

Mealworm Frass as a Novel Insect Food-Based Attractant: The Case of Bactrocera oleae (Diptera: Tephritidae)

by Ioannis E. Koufakis, Argyro P. Kalaitzaki, George D. Broufas, Antonios E. Tsagkarakis and Maria L. Pappas

Insects 2025, 16(5), 466; https://doi.org/10.3390/insects16050466 - 28 Apr 2025

Viewed by 27

Abstract

The management of Bactrocera oleae (Rossi, 1790) has relied on chemical insecticides, applied as bait or cover sprays. However, concerns over insecticide resistance and environmental impact have driven the search for more effective and eco-friendly alternatives, such as mass trapping. The aim of [...] Read more.

The management of Bactrocera oleae (Rossi, 1790) has relied on chemical insecticides, applied as bait or cover sprays. However, concerns over insecticide resistance and environmental impact have driven the search for more effective and eco-friendly alternatives, such as mass trapping. The aim of the study was to assess a novel food-based attractant, derived from Tenebrio molitor Linnaeus, 1758 excreta “Frass”, for its attractiveness to B. oleae adults compared to widely used commercial food-based attractants. Over a four-year period, five field trials were conducted in two organic olive groves in Crete, Greece, using a randomized complete block design with five or six replicate blocks. Results showed that frass-based attractants captured significantly higher number of B. oleae adults than the other tested attractants. Additionally, trap–attractant combinations were assessed to determine the most efficient mass-trapping system. Frass-based attractant deployed in Anel or container traps demonstrated significantly higher attractiveness than all commercial traps and lures tested. The significant advantages of mealworm frass as an attractant highlight its potential to enhance the monitoring and suppression of B. oleae in olive orchards. Its consistent performance, sustainability, and environmental safety make it a promising tool in integrated pest management strategies. Full article

(This article belongs to the Special Issue Advances in Insect Pest Management: Innovative Approaches to Enhance Plant Protection)

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10 pages, 668 KiB

Open AccessArticle

Impact of Sulfoxaflor on Brown Marmorated Stink Bug: Developmental and Reproductive Effects

by Ren Li, Zehua Wang, Fan Yang, Tao Su, Guanghang Qiao and Shanning Wang

Insects 2025, 16(5), 465; https://doi.org/10.3390/insects16050465 - 28 Apr 2025

Abstract

The brown marmorated stink bug, Halyomorpha halys, has become a severe threat to agriculture worldwide with continuous invasion and spread. Sulfoxaflor is the pioneering sulfoximine insecticide and has been widely employed for managing sap-feeding insect pests across diverse crops. However, the sublethal [...] Read more.

The brown marmorated stink bug, Halyomorpha halys, has become a severe threat to agriculture worldwide with continuous invasion and spread. Sulfoxaflor is the pioneering sulfoximine insecticide and has been widely employed for managing sap-feeding insect pests across diverse crops. However, the sublethal effects of sulfoxaflor on the growth and reproduction of H. halys remain unexplored. This study employed age-stage life tables and physiological parameters to evaluate the sublethal effects of sulfoxaflor on H. halys. The bioassay results indicated that the LC₂₀ and LC₅₀ values of sulfoxaflor against second-instar nymphs of H. halys were 7.75 and 20.97 mg/L, respectively. Treatment with the LC₂₀ concentration of sulfoxaflor reduced the lifespan of female adults by 11.74 days. Importantly, the oviposition period of females was shortened by 9.47 days, and the fecundity was decreased by 1.4-fold. Additionally, the activities of cytochrome P450 (P450s) and glutathione S-transferase (GSTs) enzymes in H. halys were enhanced 1.40 and 1.54 times after treatment with sublethal concentrations of sulfoxaflor. These findings demonstrate that sublethal concentrations of sulfoxaflor significantly inhibit the population development of H. halys. Moreover, the detoxification enzymes P450s and GSTs may be associated with the potential resistance to sulfoxaflor in H. halys. This information provides valuable insights into the application of sulfoxaflor in the management of this pest. Full article

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

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17 pages, 4181 KiB

Open AccessArticle

“Hostbusters”: The Bacterial Endosymbiont Wolbachia of the Parasitoid Wasp Habrobracon hebetor Improves Its Ability to Parasitize Lepidopteran Hosts

by Alsu M. Utkuzova, Ekaterina A. Chertkova, Natalia A. Kryukova, Julia M. Malysh and Yuri S. Tokarev

Insects 2025, 16(5), 464; https://doi.org/10.3390/insects16050464 - 28 Apr 2025

Viewed by 46

Abstract

Habrobracon hebetor is a globally acknowledged larval ectoparasitoid that is widely used to control lepidopteran pests. Wolbachia is a natural endosymbiont that regulates various aspects of the insect host biology. The ability of H. hebetor to paralyze and develop on lepidopteran larvae from [...] Read more.

Habrobracon hebetor is a globally acknowledged larval ectoparasitoid that is widely used to control lepidopteran pests. Wolbachia is a natural endosymbiont that regulates various aspects of the insect host biology. The ability of H. hebetor to paralyze and develop on lepidopteran larvae from five families was tested under laboratory conditions. Two lines of the wasp were used, “W+” containing a naturally occurring Wolbachia from the supergroup B, and “W−”, with the endosymbiont eradicated by antibiotic treatment, followed by propagation of 20 subsequent generations. The proportions of larvae in which host paralysis, as well as parasitoid oviposition, larval, pupal, and adult development were observed, were usually higher in W+ compared to W−. In Loxostege sticticalis, differences in these indices were not statistically significant. In Galleria mellonella, Mamestra brassicae, and Ostrinia nubilalis, some of the parasitism indices were significantly higher in W+ than in W−. In Bombyx mori and Plutella xylostella, H. hebetor could not complete its life cycle, but parasitism levels at the initial steps (from paralysis symptoms to the presence of larvae/pupae of the parasitoid) were 2–5 times lower in W− compared to W+ (p < 0.01). It can be suggested that the presence of Wolbachia is advantageous for H. hebetor, as it increases the success of parasitism in a broad range of lepidopteran hosts. Full article

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

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16 pages, 1482 KiB

Open AccessReview

Exploring the Role of mRNA Methylation in Insect Biology and Resistance

by Jiayang Zhang, Luobin Lin, Botian Huang, Huoxi Liu, Huaqin Li and Wenmei Wu

Insects 2025, 16(5), 463; https://doi.org/10.3390/insects16050463 - 28 Apr 2025

Viewed by 40

Abstract

RNA methylation, characterized by modifications such as N⁶-methyladenosine, 5-methylcytosine, and N¹-methyladenosine plays a crucial role in post-transcriptional gene regulation across diverse biological systems. While research on RNA methylation has predominantly focused on mammals, particularly its roles in epigenetic regulation [...] Read more.

RNA methylation, characterized by modifications such as N⁶-methyladenosine, 5-methylcytosine, and N¹-methyladenosine plays a crucial role in post-transcriptional gene regulation across diverse biological systems. While research on RNA methylation has predominantly focused on mammals, particularly its roles in epigenetic regulation and cancer biology, recent studies in insects have begun to explore their extensive functions in insect physiology. This review examines the mechanisms by which RNA methylation regulates growth, development, reproduction, environmental adaptation, and immune response in insects, providing insights into the biological characteristics of these organisms without prematurely speculating on pest control strategies. It aims to offer valuable insights into the role of RNA methylation in insect biology and resistance. Full article

(This article belongs to the Topic Advances in Integrated Pest Management: New Tools and Tactics for Pest Control)

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11 pages, 1168 KiB

Open AccessArticle

Elevated Plasmodium Sporozoite Infection Rates in Primary and Secondary Malaria Vectors in Anopheles stephensi-Infested Areas of Ethiopia

by Dawit Hawaria, Timotwos Amanuel, Abraham Anbesie, Daibin Zhong, Solomon Kibret, Ming-Chieh Lee, Guofa Zhou, Chloe Wang, Jiale Chen, Tafesse Matewos, Amanuel Ejeso, Chirotaw Ayele, Temesgen Yosef, Delenesaw Yewhalaw and Guiyun Yan

Insects 2025, 16(5), 462; https://doi.org/10.3390/insects16050462 - 27 Apr 2025

Viewed by 252

Abstract

Assessing bloodmeal sources and sporozoite infection rates in mosquito vectors is essential for understanding their role in malaria transmission. This study investigated these factors in Hawassa, Southern Ethiopia—an area recently invaded by Anopheles stephensi—through adult mosquito collections conducted between January and April [...] Read more.

Assessing bloodmeal sources and sporozoite infection rates in mosquito vectors is essential for understanding their role in malaria transmission. This study investigated these factors in Hawassa, Southern Ethiopia—an area recently invaded by Anopheles stephensi—through adult mosquito collections conducted between January and April 2023 using BG-Pro traps, CDC Light Traps, and Prokopack Aspirators. A total of 738 female Anopheles mosquitoes were collected, including An. arabiensis (72.9%), An. pharoensis (13.4%), An. stephensi (7.5%), and An. coustani (6.2%). Human Blood Index (HBI) values were 23.3% for An. arabiensis, 43.8% for An. pharoensis, 8.3% for An. stephensi, and 25.0% for An. coustani. Plasmodium infection was detected in 8% of An. arabiensis and 4.7% of An. pharoensis, while An. stephensi and An. coustani were uninfected. The findings highlight the presence of multiple competent malaria vectors, with significant infection rates observed in both primary and secondary species, underscoring the need to include secondary vectors in control and surveillance programs. The detection of An. stephensi alongside native vectors adds complexity to malaria control efforts, reinforcing the importance of continuous monitoring to understand the changing dynamics of vector populations and their roles in transmission. Full article

(This article belongs to the Special Issue Insecticide Resistance in Mosquitoes)

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23 pages, 14601 KiB

Open AccessArticle

Deciphering the Olfactory Mechanisms of Sitotroga cerealella Olivier (Lepidoptera: Gelechiidae): Insights from Transcriptome Analysis and Molecular Docking

by Hui Li, Sheng Qiao, Xiwen Hong and Yangyang Wei

Insects 2025, 16(5), 461; https://doi.org/10.3390/insects16050461 - 27 Apr 2025

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Abstract

Olfaction is crucial for insect activities such as host seeking, foraging, oviposition, and predator avoidance. While olfactory proteins have been identified across several insect species, their specific functions are largely enigmatic. In this study, we investigated the olfactory proteins of the Angoumois grain [...] Read more.

Olfaction is crucial for insect activities such as host seeking, foraging, oviposition, and predator avoidance. While olfactory proteins have been identified across several insect species, their specific functions are largely enigmatic. In this study, we investigated the olfactory proteins of the Angoumois grain moth, Sitotroga cerealella Olivier. A total of 165 presumptive olfactory genes were identified in the antennal transcriptome of S. cerealella, encompassing 33 odorant-binding proteins (OBPs), 10 chemosensory proteins (CSPs), 58 odorant receptors (ORs), 41 ionotropic receptors (IRs), 21 gustatory receptors (GRs), and 2 sensory neuron membrane proteins (SNMPs). BLASTX and a phylogenetic analysis showed a high similarity of these genes to the orthologs in other model insects. A qRT-PCR analysis demonstrated that ScerOBP15 and ScerOBP23 are specifically and highly expressed in antennae, exhibiting male-biased expression patterns. Moreover, molecular docking revealed their strong binding affinity to the wheat volatiles n-heptadecane and geranyl acetone. Also, the potential active sites within ScerOBP15 and ScerOBP23 that engage with these volatiles have been identified, implying a possible role in host localization. Our findings shed light on the mechanisms underlying the behavioral responses of S. cerealella to wheat odors, enhance our comprehension of their olfactory processes, and pave the way for the development of highly specific and sustainable pest management strategies. Full article

(This article belongs to the Special Issue Research on Insect Molecular Biology)

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10 pages, 1013 KiB

Open AccessArticle

miRNA Expression Response of Aedes aegypti (Linnaeus 1762) (Diptera: Culicidae) to Imidacloprid Exposure

by Gerardo Trujillo-Rodríguez, Mariana Lizbeth Jiménez-Martínez, Elda Flores-Contreras, Everardo González Gonzalez, María de Lourdes Ramírez Ahuja, Idalia Garza Veloz, Adriana E. Flores Suarez, Fabian Correa Morales, Felipe Dzul Manzanilla, Iram P. Rodriguez Sanchez and Margarita L. Martínez Fierro

Insects 2025, 16(5), 460; https://doi.org/10.3390/insects16050460 - 27 Apr 2025

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Abstract

Aedes aegypti is a major vector of arboviruses, including dengue, Zika, chikungunya, yellow fever, and Mayaro. The extensive use of insecticides has led to resistance, complicating vector control efforts. MicroRNAs (miRNAs) are post-transcriptional regulators involved in detoxification and stress adaptation; however, their role [...] Read more.

Aedes aegypti is a major vector of arboviruses, including dengue, Zika, chikungunya, yellow fever, and Mayaro. The extensive use of insecticides has led to resistance, complicating vector control efforts. MicroRNAs (miRNAs) are post-transcriptional regulators involved in detoxification and stress adaptation; however, their role in the insecticide response of Ae. aegypti remains unclear. This study analyzed miRNA expression in Ae. aegypti following imidacloprid exposure, comparing a field strain, Martinez de la Torre from Mexico (MT), and a susceptible reference strain, New Orleans (NO). Small RNA sequencing identified 96 miRNAs, with miR-1, miR-281-5p, miR-100, and miR-184 being consistently expressed across all conditions. In contrast, let-7, miR-124, and miR-13-3p were exclusively detected in wild mosquitoes exposed to imidacloprid, while miR-14 and miR-275-3p showed condition-specific expression. Distinct miRNA expression patterns were observed between the field and susceptible strains, with specific miRNAs showing condition-dependent expression. These findings suggest that certain miRNAs may serve as potential biomarkers for resistance monitoring, contributing to a better understanding of insecticide response mechanisms and informing novel vector control strategies. Full article

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

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12 pages, 1043 KiB

Open AccessArticle

Field-Based Evaluation of Insecticide Effectiveness on Megalurothrips usitatus in Guangdong, China: Implications for Pest Control Strategies

by Zhengke Peng, Mengni Li, Chaosong Guo, Huixin Zheng, Mingyue Wu, Fei Yin, Yong Xiao, Huanhuan Wang, Xiangyi Kong, Myron P. Zalucki, Wen Xie and Zhenyu Li

Insects 2025, 16(5), 459; https://doi.org/10.3390/insects16050459 - 27 Apr 2025

Viewed by 68

Abstract

In southern China, cowpea production is severely threatened by Megalurothrips usitatus due to its fast-evolving resistance to insecticides. The toxicity monitoring of commonly used insecticides against field populations provides key information for the resistance management of pests. In this study, field populations of [...] Read more.

In southern China, cowpea production is severely threatened by Megalurothrips usitatus due to its fast-evolving resistance to insecticides. The toxicity monitoring of commonly used insecticides against field populations provides key information for the resistance management of pests. In this study, field populations of Megalurothrips usitatus were collected from three locations (QY, YF, MM) in Guangdong, and the sensitivity of these populations against insecticides was determined by using a thrips insecticides bioassay system (TIBS) method. The bioassay results indicated there were sensitivity variances to insecticides between these three field populations. Among these 10 insecticides, spinetoram and spinosad both showed high toxicity against all three field populations. In addition, broflanilide for QY, emamectin benzoate for YF, and emamectin benzoate and cyantraniliprole for MM were suggested as alternate insecticides to alleviate selective pressure from insecticides on field populations. In field experiments, the corrected control efficacy of cyantraniliprole and spinetoram against M. usitatus was over 75% at 7 dpa, which proved to be ideal insecticides for field application. These field-based results provide guidance for chemical control against thrips and can be valuable in proposing appropriate strategies for thrips resistance management. Full article

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

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20 pages, 5859 KiB

Open AccessArticle

A Complex of Lance Flies (Diptera: Lonchaeidae) Infesting Figs in Veracruz, Mexico, with the Description of a New Species

by Rodrigo Lasa, Laura Navarro-de-la-Fuente, Iain MacGowan and Trevor Williams

Insects 2025, 16(5), 458; https://doi.org/10.3390/insects16050458 - 27 Apr 2025

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Abstract

The black fig fly, Silba adipata, and a complex of Neosilba species have emerged as major fig pests in Veracruz, Mexico. To assess infestation patterns and species composition, we sampled figs during one production cycle (March–October 2024) in two plantations. A total [...] Read more.

The black fig fly, Silba adipata, and a complex of Neosilba species have emerged as major fig pests in Veracruz, Mexico. To assess infestation patterns and species composition, we sampled figs during one production cycle (March–October 2024) in two plantations. A total of 1647 S. adipata (821 females, 826 males) and 1250 Neosilba spp. (628 females, 622 males) emerged from samples. One species, Neosilba recurva, is described as new based on the characteristics of the male genitalia and COI sequencing. Neosilba spp. outnumbered S. adipata in the preharvest period, after which S. adipata became dominant. S. adipata emerged ~14 days earlier than Neosilba spp. Infestation by S. adipata caused uniform fig reddening, while Neosilba spp. produced patchy redness near larval exit holes. Approximately 65% of figs were lost to lonchaeid infestation preharvest. Based on male genitalia, we identified Neosilba batesi and N. recurva sp. nov. (that together comprised 64% of samples), as well as Neosilba sp.1 (26%) and N. glaberrima (10%), but COI sequences revealed greater diversity. Neosilba batesi formed a clade that did not match a Floridan sequence. Neosilba glaberrima clustered near N. pendula from Brazil, but another sequence diverged, suggesting the presence of an additional, undescribed species, Neosilba sp.2? Neosilba recurva and Neosilba sp.1, together with the newly described N. flavitarsis from Veracruz, formed distinct genetic branches, supporting their specific status. Full article

(This article belongs to the Special Issue Fly Biology, Ecology, Behavior and Management—2nd Edition)

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24 pages, 2189 KiB

Open AccessReview

Medical Potential of Insect Symbionts

by Fanglei Fan, Zhengyan Wang, Qiong Luo, Zhiyuan Liu, Yu Xiao and Yonglin Ren

Insects 2025, 16(5), 457; https://doi.org/10.3390/insects16050457 - 26 Apr 2025

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Abstract

Insect symbionts and their metabolites are complex and diverse and are gradually becoming an important source of new medical materials. Some culturable symbionts from insects produce a variety of active compounds with medical potential. Among them, fatty acids, antibacterial peptides, polyene macrolides, alkaloids, [...] Read more.

Insect symbionts and their metabolites are complex and diverse and are gradually becoming an important source of new medical materials. Some culturable symbionts from insects produce a variety of active compounds with medical potential. Among them, fatty acids, antibacterial peptides, polyene macrolides, alkaloids, and roseoflavin can inhibit the growth of human pathogenic bacteria and fungi; lipases, yeast killer toxins, reactive oxygen species, pyridines, polyethers, macrotetrolide nactins, and macrolides can kill human parasites; and peptides and polyketides can inhibit human tumors. However, due to difficulty in the culture of symbionts in vitro, difficulty in targeting bacteria to specific sites in the human body, the limited capability of symbionts to produce active metabolites in vitro, inconsistent clinical research results, adverse reactions on humans, and the development of antibiotic resistance, the application of insect symbionts and their metabolites in the medical field remains in its infancy. This paper summarizes the medical potential of insect symbionts and their metabolites and analyzes the status quo and existing problems with their medical application. Possible solutions to these problems are also proposed, with the aim of hastening the utilization of insect symbionts and their metabolites in the medical field. Full article

(This article belongs to the Section Role of Insects in Human Society)

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33 pages, 8331 KiB

Open AccessArticle

Contribution to the African Ladybird Genus Epipleuria Fürsch (Coccinellidae: Coccidulini) with Description of a New Genus

by Tomasz Czerwiński and Karol Szawaryn

Insects 2025, 16(5), 456; https://doi.org/10.3390/insects16050456 - 25 Apr 2025

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Abstract

The endemic African genus Epipleuria Fürsch is re-described, diagnosed and confronted with African species of the closely related genus Rhyzobius Stephens. The validity of the genus Epipleuria is confirmed. Two new species, Epipleuria capensis sp. nov. and Epipleuria tsitsikamma sp. nov., from [...] Read more.

The endemic African genus Epipleuria Fürsch is re-described, diagnosed and confronted with African species of the closely related genus Rhyzobius Stephens. The validity of the genus Epipleuria is confirmed. Two new species, Epipleuria capensis sp. nov. and Epipleuria tsitsikamma sp. nov., from the Republic of South Africa are described. Additionally, the male genitalia of Epipleuria natalensis Fürsch, 2001, are described and illustrated for the first time. Epipleuria endroedyi Fürsch, 2001; Epipleuria mahnerti Fürsch, 2001; and Rhyzobius stillatus Fürsch, 1992, are transferred to the newly established genus Pseudoepipleuria gen. nov. Full article

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

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13 pages, 1802 KiB

Open AccessArticle

Flupyradifurone Exhibits Greater Toxicity to the Asian Bumblebee Bombus lantschouensis Compared to the European Bumblebee Bombus terrestris

by Chunting Jie, Hong Zhang, Ziyu Zhou, Zhengying Miao, Bo Han, Baodi Guo, Yi Guo, Xiao Hu, Shahid Iqbal, Bingshuai Wei, Jiaxing Huang, Pingli Dai and Jiandong An

Insects 2025, 16(5), 455; https://doi.org/10.3390/insects16050455 - 25 Apr 2025

Viewed by 86

Abstract

Pesticides are considered a major factor in the decline of bee populations. Flupyradifurone, a novel insecticide, is believed to be relatively ‘bee-safe’. This study aims to evaluate the acute and chronic toxicity of flupyradifurone and assess its risks to both commercial bumblebee Bombus [...] Read more.

Pesticides are considered a major factor in the decline of bee populations. Flupyradifurone, a novel insecticide, is believed to be relatively ‘bee-safe’. This study aims to evaluate the acute and chronic toxicity of flupyradifurone and assess its risks to both commercial bumblebee Bombus terrestris and the Asian native species B. lantschouensis. Oral toxicity tests demonstrated species-specific sensitivity, with B. lantschouensis exhibiting 5.4-fold higher acute toxicity (72-h LD₅₀: 5.1 μg/bee vs. 28 μg/bee) and 3-fold lower chronic toxicity (No Observed Adverse Effect Concentration, NOAEC: 20 μg/mL vs. 60 μg/mL) compared to B. terrestris. Risk assessments indicated low Hazard Quotients (HQ) of 4 for B. terrestris and 20 for B. lantschouensis. However, the Exposure Toxicity Ratio (ETR) values from both screening and first-tier assessments exceeded the trigger levels, necessitating further testing. This study provides crucial data on the acute and chronic toxic effects of flupyradifurone and highlights the need for more comprehensive insecticide risk assessments, particularly for non-Apis pollinators, to better protect these vital species. Full article

(This article belongs to the Special Issue Bumblebee Biology and Ecology)

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22 pages, 94322 KiB

Open AccessArticle

The Weevil Genus Rhamphus (Curculionidae, Curculioninae) in Southern Africa—Description of Thirteen New Species

by Roberto Caldara and Michele Tedeschi

Insects 2025, 16(5), 454; https://doi.org/10.3390/insects16050454 - 25 Apr 2025

Viewed by 93

Abstract

The southern African species of the genus Rhamphus Clairville, 1798, is herein revised for the first time. Fourteen species are recognized, 13 of which are new to science. The single known species was Rhamphus namibicus Korotyaev, 1994 (Namibia), whereas the new species are [...] Read more.

The southern African species of the genus Rhamphus Clairville, 1798, is herein revised for the first time. Fourteen species are recognized, 13 of which are new to science. The single known species was Rhamphus namibicus Korotyaev, 1994 (Namibia), whereas the new species are R. carinatus sp. nov. (South Africa: Limpopo; Zimbabwe), R. densepunctatus sp. nov. (South Africa: Western Cape), R. gigas sp. nov. (Zambia), R. glaber sp. nov. (South Africa: Mpumalanga), R. globipennis sp. nov. (South Africa: Mpumalanga, Limpopo, KwaZulu-Natal, Eastern Cape, Western Cape), R. hispidulus sp. nov. (South Africa: Eastern Cape), R. indifferens sp. nov. (South Africa: Gauteng, KwaZulu-Natal, Eastern Cape), R. levipennis sp. nov. (South Africa: Mpumalanga; Zimbabwe), R. longitarsis sp. nov. (Southern Namibia; South Africa: Northern Cape), R. obesulus sp. nov. (South Africa: Eastern Cape), R. pilosulus sp. nov. (South Africa: Mpumalanga, KwaZulu-Natal; Zimbabwe), R. scaber sp. nov. (South Africa: KwaZulu-Natal, Eastern Cape), R. squamidorsum sp. nov. (South Africa: Eastern Cape, Western Cape). Based on morphological characters, the species are separated into four informal groups. In considering possible relationships between these species and those from other regions, host-plant associations are also discussed. Full article

(This article belongs to the Special Issue Beetles in Integrative Entomology: Biology, Taxonomy, and Conservation)

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13 pages, 1324 KiB

Open AccessArticle

Reduction in Acute Bee Paralysis Virus Infection and Mortality in Honey Bees (Apis mellifera) by RNA Interference Technology

by Cecilia Ferrufino, Alejandra Scannapieco, Romina María Russo, Fernanda Noemí Gonzalez, Ricardo Salvador and María José Dus Santos

Insects 2025, 16(5), 453; https://doi.org/10.3390/insects16050453 - 25 Apr 2025

Viewed by 77

Abstract

In Argentina, various studies have reported the detection of multiple viruses in honey-producing and queen-rearing apiaries, with Aparavirus apisacutum, the causal agent of acute bee paralysis (ABP), demonstrating a particularly high prevalence. The potential of RNA interference (RNAi) as a strategy to [...] Read more.

In Argentina, various studies have reported the detection of multiple viruses in honey-producing and queen-rearing apiaries, with Aparavirus apisacutum, the causal agent of acute bee paralysis (ABP), demonstrating a particularly high prevalence. The potential of RNA interference (RNAi) as a strategy to control honey bee viruses has been explored, with initial findings indicating that RNAi could aid in mitigating the economic losses associated with viral infections. This study aimed to evaluate the effect of RNAi technology mediated by double-stranded RNA (dsRNA) on the dynamics of ABPV infection in adult honey bees. Fragments of the ABPV replicase and VP1 genes were used as templates for dsRNA synthesis via in vitro transcription. A gene silencing experiment was conducted through oral administration using five treatments: control, specific dsRNA + Virus, Virus alone, specific dsRNA alone, and non-specific dsRNA + virus. Bee survival was recorded over 10 days for all treatments, and samples were subsequently processed for viral quantification using quantitative real-time PCR. The oral administration of specific dsRNA reduced the viral replication curve, decreased the average viral loads and increased bee survival. This is the first report demonstrating the reduction in ABPV infection in adult honey bees through post-transcriptional gene silencing achieved via oral administration of dsRNA. Full article

(This article belongs to the Section Insect Behavior and Pathology)

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19 pages, 1067 KiB

Open AccessArticle

Morpho-Molecular Discordance and Cryptic Diversity in Jumping Bristletails: A Mitogenomic Analysis of Pedetontus silvestrii (Insecta: Archaeognatha: Machilidae)

by Wei Cen, Jia-Wen Li, Jia-Tao He, Xin-Yu Chen, Luo-Ying Li, Kenneth B. Storey, Dan-Na Yu and Jia-Yong Zhang

Insects 2025, 16(5), 452; https://doi.org/10.3390/insects16050452 - 25 Apr 2025

Viewed by 244

Abstract

Archaeognatha (bristletails) represent an evolutionarily significant but understudied insect group. Notably, the morphological identification method proposed by Mendes for Archaeognatha has certain limitations, which may lead to the underestimation or misidentification of some cryptic species. To address this issue, we employed an integrated [...] Read more.

Archaeognatha (bristletails) represent an evolutionarily significant but understudied insect group. Notably, the morphological identification method proposed by Mendes for Archaeognatha has certain limitations, which may lead to the underestimation or misidentification of some cryptic species. To address this issue, we employed an integrated strategy that combines morphological and molecular identification methods. Therefore, this study aimed to (1) identify cryptic diversity within Pedetontus silvestrii using mitogenomic data; (2) clarify phylogenetic relationships among Archaeognatha lineages; and (3) estimate divergence times for key taxonomic splits. We analyzed mitochondrial genomes from six P. silvestrii populations (Liaoning, Jilin, and Hebei Provinces) alongside 14 published Archaeognatha genomes. Key findings include the following: (1) Integrative analyses of genetic distances, phylogenetic reconstruction, bPTP-based molecular species delimitation, and divergence time estimation collectively revealed four evolutionarily distinct lineages within P. silvestrii. (2) Machilidae and Machilinae were non-monophyletic, whereas Petrobiellinae showed close affinity to Meinertellidae. (3) Archaeognatha originated ~301.19 Mya (Late Carboniferous); the Machilinae–Petrobiinae split occurred approximately 153.99 Mya (Jurassic). This study underscores the critical importance of mitogenomic analysis in elucidating cryptic biodiversity, while emphasizing the necessity of integrating morphological identification with molecular characterization for comprehensive species delineation in future taxonomic investigations. Full article

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

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8 pages, 2565 KiB

Open AccessArticle

First Record of Caloapenesia (Hymenoptera, Bethylidae) from China with Description of One New Species

by Chunhong Wang, Junhua He, Celso O. Azevedo and Xuexin Chen

Insects 2025, 16(5), 451; https://doi.org/10.3390/insects16050451 - 24 Apr 2025

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Abstract

The genus Caloapenesia, only known from the Oriental region, comprises nineteen species, seventeen of which are recorded from Thailand and the Philippines, countries adjacent to China. During our examination of bethylid specimens from southern China, we discovered Caloapenesia xui sp. nov. from [...] Read more.

The genus Caloapenesia, only known from the Oriental region, comprises nineteen species, seventeen of which are recorded from Thailand and the Philippines, countries adjacent to China. During our examination of bethylid specimens from southern China, we discovered Caloapenesia xui sp. nov. from Guangdong Province, representing the northernmost record for the genus. The new species is described and illustrated, and an updated key to the males of Caloapenesia is provided. Full article

(This article belongs to the Special Issue Taxonomy and Phylogeny and Evolution of Parasitic Hymenoptera and Biological Control)

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20 pages, 2747 KiB

Open AccessArticle

Potential Distribution of Tribe Erythroneurini in China Based on the R-Optimized MaxEnt Model, with Implications for Management

by Xiaojuan Yuan, Weiwei Ran, Wenming Xu, Yuanqi Zhao, Di Su and Yuehua Song

Insects 2025, 16(5), 450; https://doi.org/10.3390/insects16050450 - 24 Apr 2025

Viewed by 229

Abstract

This study examines the distribution dynamics of the tribe Erythroneurini, a group of economically significant leafhoppers in China that pose threats to crops through sap feeding and virus transmission, while also serving as valuable ecological indicators due to their sensitivity to environmental changes. [...] Read more.

This study examines the distribution dynamics of the tribe Erythroneurini, a group of economically significant leafhoppers in China that pose threats to crops through sap feeding and virus transmission, while also serving as valuable ecological indicators due to their sensitivity to environmental changes. Through a systematic evaluation of 12 species distribution models (SDMs), we ultimately selected the Maximum Entropy (MaxEnt) model for predicting species distributions. The R-optimized MaxEnt model incorporated 11 environmental variables and 218 occurrence records to assess habitat suitability under historical, current, and future climate scenarios (SSP1-2.6 and SSP5-8.5). The model was configured with LQP features and a default regularization multiplier value of 1. Results reveal that temperature (BIO6, BIO2, BIO4) and precipitation (BIO12) are the primary drivers of habitat suitability, with tropical and subtropical regions identified as the most favorable. Future projections indicate a complex pattern of habitat contraction and expansion, with a notable northward shift toward higher latitudes under climate change. These findings highlight the profound impact of climate change on Erythroneurini distribution, underscoring the need for proactive management. Implementing long-term monitoring and targeted control in vulnerable regions mitigates ecological and agricultural risks, supporting sustainable pest management and fostering the integration of ecological conservation with agricultural development. Full article

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

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16 pages, 3433 KiB

Open AccessArticle

Azoxystrobin-Induced Physiological and Biochemical Alterations in Apis mellifera Workers of Different Ages

by Xinle Duan, Wenlong Tong, Bingfang Tao, Huanjing Yao, Manqiong Xiong, Huiping Liu, Shaokang Huang and Jianghong Li

Insects 2025, 16(5), 449; https://doi.org/10.3390/insects16050449 - 24 Apr 2025

Viewed by 175

Abstract

Fungal diseases of agricultural crops cause severe economic losses to the growers. For the control of these diseases, azoxystrobin is one of the recommended fungicides. This fungicide is systemic in action and is expected to reach the floral part of the treated crop [...] Read more.

Fungal diseases of agricultural crops cause severe economic losses to the growers. For the control of these diseases, azoxystrobin is one of the recommended fungicides. This fungicide is systemic in action and is expected to reach the floral part of the treated crop and its residue in the pollen and nectar, the natural food sources of honey bees, which could be collected and fed on by honey bees, thus affecting their health. The purpose of this study was to determine the physiological and chemical changes caused by this fungicide in honey bee workers (Apis mellifera L). Workers of this honey bee at 1, 8, and 21 days old were treated with 125, 167, and 250 mg/L concentrations of azoxystrobin for seven days; their survival rates, activities of carboxylesterase (CarE), glutathione S-transferases (GSTs), cytochrome P450 enzyme (CYP450), catalase (CAT), and superoxide dismutase (SOD) enzymes, and the expression levels of immune (Aba, Api, Def1, and Hym) and nutrition genes (Ilp1, Ilp2, and Vg) were detected. Our findings revealed that azoxystrobin affected the survival of workers, particularly 1- and 21-day-old workers, who responded to azoxystrobin stress with increased activities of detoxification and protective enzymes, which might have physiological costs. Additionally, azoxystrobin affected the expression of immune and nutrition genes, with a decreased expression trend in 21-day-old workers compared to the 1- and 8-day-old workers, leading to reduced resistance to external stressors and increased mortality rates. These findings provide important insights into the adverse effects of azoxystrobin on workers of different ages and emphasize the potential risks of this chemical to colony stability and individual health. This study recommends an urgent ban on such a harmful fungicide being used for fungi control in agriculture, especially during plant flowering. Full article

(This article belongs to the Special Issue Bee Health and Beehive Management in a Changing World)

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18 pages, 3019 KiB

Open AccessArticle

Larvicidal Activity of Extracts from the Artemisia arborescens L. Plant and Hyrtios erectus Sponge Against the Culex pipiens Mosquito (Diptera: Culicidae) and Toxicological Assessment on Danio rerio Zebrafish Embryos as Non-Target Organism

by Sadeem A. Alqurashi, Ashraf M. Ahmed, Ali A. El Gamal, Shaza M. Al-Massarani, Omer A. Basudan, Diaa T. A. Youssef, Lamiaa A. Shaala and Muhammad Farooq Khan

Insects 2025, 16(5), 448; https://doi.org/10.3390/insects16050448 - 24 Apr 2025

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Abstract

There is a growing need for eco-friendly methods to control disease-carrying insects. The present study aimed to investigate the larvicidal activity of methanolic extracts and their various fractions from a plant, Artemisia arborescens L., and a marine sponge, Hyrtios erectus, against the [...] Read more.

There is a growing need for eco-friendly methods to control disease-carrying insects. The present study aimed to investigate the larvicidal activity of methanolic extracts and their various fractions from a plant, Artemisia arborescens L., and a marine sponge, Hyrtios erectus, against the mosquito, Culex pipiens L. Crude methanolic extracts of A. arborescens and H. erectus were prepared by maceration and successive fractionation were obtained using the liquid–liquid partition of crude extracts. The larvicidal activity of the extracts and their fractions was determined according to the WHO standard method. The results revealed that the n-hexane fraction of A. arborescens exhibited the highest larvicidal activity (LC₅₀ 346.74 μg/mL), exceeding the efficacy of the crude extract and other fractions. Furthermore, the sponge’s n-hexane (LC₅₀ 68.39 μg/mL), chloroform (LC₅₀ 63.03 μg/mL), and n-butanol (LC₅₀ 71.23 μg/mL) fractions showed a significant 3.9 to 4.5 times increase in the larvicidal potency compared to its crude extract (LC₅₀ = 280.74 μg/mL). The safety of the sponge extracts was tested in the embryos of zebrafish as a non-target organism. In this regard, the crude methanolic extract and n-butanol fraction exhibited weak toxicity and chloroform fraction showed no detectable toxicity. This study suggests the H. erectus sponge as a source for developing safe natural substitutes for use in the battle against Cx. pipiens mosquito, which may help in reducing the spread of mosquito vectors and mosquito-borne diseases. Full article

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

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12 pages, 1649 KiB

Open AccessArticle

Non-Host Status of Green Lemon Fruit (Citrus × limon (L.) Burman f. cv. Lisbon) to Oriental Fruit Fly, Mediterranean Fruit Fly, and Melon Fly (Diptera: Tephritidae) in Hawaii

by Peter A. Follett, Xiuxiu Sun and Spencer S. Walse

Insects 2025, 16(5), 447; https://doi.org/10.3390/insects16050447 - 24 Apr 2025

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Abstract

We investigated the host status of harvest-ready green lemons, Citrus × limon (L.) Burm. F. cv. Lisbon (Rutaceae), to Oriental fruit fly (Bactrocera dorsalis), Mediterranean fruit fly (Ceratitis capitata), and melon fly (Zeugodacus cucurbitae) (Diptera: Tephritidae) in [...] Read more.

We investigated the host status of harvest-ready green lemons, Citrus × limon (L.) Burm. F. cv. Lisbon (Rutaceae), to Oriental fruit fly (Bactrocera dorsalis), Mediterranean fruit fly (Ceratitis capitata), and melon fly (Zeugodacus cucurbitae) (Diptera: Tephritidae) in Hawaii using laboratory and field studies. In forced-infestation small-cage exposures (using 25 × 25 × 25 cm screened cages with 50 gravid females), punctured lemons were infested by Oriental fruit fly, Mediterranean fruit fly, and melon fly, whereas undamaged lemons were not infested. Field collection, packing, and incubation of approximately 58,420 mixed-grade fruit (commercial export quality and off grades) found no natural infestations and resulted in no fruit fly emergence. Field studies enclosing fruit on trees in sleeve cages that were stocked with 50 gravid females per cage resulted in no infestations. Commercial export-grade green Lisbon lemon fruit should, therefore, be considered a non-host for Oriental fruit fly, Mediterranean fruit fly, and melon fly. Full article

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

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21 pages, 3809 KiB

Open AccessArticle

The Characteristics and Functions of SSRs and SNPs Based on the Transcriptome of Tuta absoluta Exposed to Different Concentrations of Abamectin and Chlorantraniliprole

by Fanxue Zhang, Meimei Mu, Zonglin Wang, Haoran Zhang, Yilan Song and Rong Xiao

Insects 2025, 16(5), 446; https://doi.org/10.3390/insects16050446 - 24 Apr 2025

Viewed by 81

Abstract

Tuta absoluta (Meyrick) is an important invasive pest that seriously affects the yield and quality of tomatoes. In this study, based on the previously obtained transcriptome data, a total of 25,123 SSR loci and 332,537 SNP loci were identified. The identified SSRs had [...] Read more.

Tuta absoluta (Meyrick) is an important invasive pest that seriously affects the yield and quality of tomatoes. In this study, based on the previously obtained transcriptome data, a total of 25,123 SSR loci and 332,537 SNP loci were identified. The identified SSRs had occurrence and appearance frequencies of 28.62% and 40.60%, respectively. SSRs with a length equal to or greater than 12 bp constituted 58.25% of the total SSR loci. Through the analysis of GO, COG annotations, and the KEGG pathway database, it was revealed that the majority of SSR-transcripts were involved in fundamental cellular metabolic functions. In addition, the frequency of SNP occurrence was approximately one SNP locus per 175 base pairs (bp), and the transition type was the main variant type. The functional annotations of SNP-transcripts were primarily concentrated in biological synthesis pathways such as peroxisome, RNA transport, carbon metabolism, and protein processing in the endoplasmic reticulum. These synthesis pathways are involved in the detoxification mechanism of T. absoluta and contribute to its enhanced survival under pesticide susceptibility. These findings provide valuable data for constructing genetic maps, assessing genetic diversity, and determining functional orientation in insects, and they also provide basic data for the molecular mechanism of T. absoluta ‘s response to pesticide susceptibility. Full article

(This article belongs to the Special Issue Women’s Special Issue Series: Insects)

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14 pages, 5249 KiB

Open AccessArticle

Selection of Bactrocera tau (Walker) Reference Genes for Quantitative Real-Time PCR

by Yutong Zhai, Yonghao Yu, Pengfei Xu, Xianru Zeng, Xiuzhen Long, Dewei Wei, Zhan He and Xuyuan Gao

Insects 2025, 16(5), 445; https://doi.org/10.3390/insects16050445 - 24 Apr 2025

Viewed by 143

Abstract

The selection of appropriate reference genes is critical for standardizing quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) data, thereby ensuring accurate and reliable results of gene expression analysis. In this study, we identified 10 candidate reference genes (encoding α-tubulin, G6PDH, [...] Read more.

The selection of appropriate reference genes is critical for standardizing quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) data, thereby ensuring accurate and reliable results of gene expression analysis. In this study, we identified 10 candidate reference genes (encoding α-tubulin, G6PDH, Rab1, RT, RPS13, β-tubulin, DPH1, HSP90, GAPDH, and CP) and evaluated their suitability for use as reference genes in the pest insect, Bactrocera tau. Analysis was conducted using three software-based methods—Delta CT, NormFinder, and BestKeeper—alongside the online tool RefFinder. Expression levels of these genes were analyzed across various B. tau developmental stages and body parts. The overall ranking of reference gene stability scores was as follows: α-tubulin > G6PDH > CP > β-tubulin > RT > HSP90 > GAPDH > DPH1 > RPS13 > Rab1. Ultimately, α-tubulin and G6PDH were identified as the most stable reference genes for B. tau. Full article

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

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