Insects

21 pages, 3240 KB

Open AccessArticle

Phytochemical-Mediated Tritrophic Interactions: Effects of Pepper and Eggplant Cultivars on the Green Peach Aphid Myzus persicae (Sulzer) and Its Predators

by Zahra Golparvar, Mahdi Hassanpour, Ali Golizadeh, Gadir Nouri Ganbalani, Hooshang Rafiee Dastjerdi, Tomasz Oszako, Mojtaba Hosseini, Stanisław Łuniewski, Mikołaj Jalinik and Ali Chenari Bouket

Insects 2025, 16(10), 1050; https://doi.org/10.3390/insects16101050 - 15 Oct 2025

Abstract

The diverse phytochemical profiles of host plants can significantly influence their interactions with herbivores and natural enemies. This study investigated the ‘bottom-up’ effects of several bell pepper and eggplant cultivars on the development, reproduction, and survival of the green peach aphid, Myzus persicae [...] Read more.

The diverse phytochemical profiles of host plants can significantly influence their interactions with herbivores and natural enemies. This study investigated the ‘bottom-up’ effects of several bell pepper and eggplant cultivars on the development, reproduction, and survival of the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), and its predators, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) and Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). We analyzed the leaves of each cultivar for levels of total flavonoids, phenols, anthocyanins, and key defensive enzymes. The eggplant cultivar ‘Longo’ exhibited the highest concentration of secondary metabolites. Aphid populations reared on this cultivar’s leaves showed a slower growth rate compared to those on other cultivars. Conversely, predators fed on these aphids demonstrated higher rates of population growth and produced more offspring. Accordingly, the intrinsic rate of natural increase (r) was lower for aphids feeding on ‘Longo’, but significantly higher for both A. aphidimyza and C. carnea when fed those aphids. These results demonstrate that elevated secondary metabolites on ‘Longo’ suppress the performance of M. persicae while enhancing predator efficiency, thereby providing a phytochemical-based approach that can serve as an effective component of integrated pest management (IPM) programs. Full article

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

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15 pages, 2058 KB

Open AccessArticle

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

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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21 pages, 115665 KB

Open AccessArticle

Report on Leg Sensilla of Notonectidae (Hemiptera, Heteroptera)

by Meng-Yao Fan and Tong-Yin Xie

Insects 2025, 16(10), 1048; https://doi.org/10.3390/insects16101048 - 14 Oct 2025

Abstract

Notonectidae belongs to the infraorder Nepomorpha within the order Hemiptera. The aim of this study was to analyze the morphological types and arrangement of leg sensilla in Anisops, Enithares and Notonecta. A variety of sensilla are distributed on the legs. These [...] Read more.

Notonectidae belongs to the infraorder Nepomorpha within the order Hemiptera. The aim of this study was to analyze the morphological types and arrangement of leg sensilla in Anisops, Enithares and Notonecta. A variety of sensilla are distributed on the legs. These sensilla are responsible for receiving signals from the external environment. Mechanoreceptors exhibit the highest diversity. Using a scanning electron microscope, ten types of sensilla were identified on the legs of seventeen species from Notonectidae. Basic types of mechanoreceptors, including sensilla trichodea (ST1, ST2), sensilla chaetica (SCh1, SCh2), sensilla basiconica (SB2) and sensilla campaniformia (SCa), were distributed across all the studied species. In Anisops, sensilla arch-shaped (SAr) and sensilla spoon-shaped (SSp) were reported for the first time. Additionally, six subtypes of ST were distinguished in Anisops, among which ST3, ST4, ST5 and ST6 are unique. In Enithares and Notonecta, sensilla styloconica (SS) were observed; these sensilla are hypothesized to function as both mechanoreceptors and gustatory receptors. Beyond mechanoreceptors, we also identified thermo-hygroreceptors—sensilla ampullacea (SA) and sensilla coeloconica (SCo)—as well as a potential olfactory sensilla type, namely, sensilla placodea multilobated (SPM). These findings suggest that Notonectidae leg sensilla play an important role in the perception of aquatic environments and prey localization. Full article

(This article belongs to the Special Issue Aquatic Insects Biodiversity and eDNA Monitoring)

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16 pages, 7361 KB

Open AccessArticle

Integrated Transcriptomic and Metabolomic Insights into “I See You” (ISY) Defensive Behavior in Apis cerana Against Vespa velutina

by Yijie Chen, Xueling Xu, Yingjiao Li, Ning Ji, Yiwei Ruan, Mei Yang, Hongji Huang, Liulin Yang, Xiaoyu Cao and Jianghong Li

Insects 2025, 16(10), 1047; https://doi.org/10.3390/insects16101047 - 13 Oct 2025

Abstract

Vespa velutina (V. velutina) is a globally widespread predator of honeybees, posing a serious threat to them. Apis cerana (A. cerana) has acquired the ability to partially thwart the predation of the wasps, but the molecular mechanism by which [...] Read more.

Vespa velutina (V. velutina) is a globally widespread predator of honeybees, posing a serious threat to them. Apis cerana (A. cerana) has acquired the ability to partially thwart the predation of the wasps, but the molecular mechanism by which it responds to V. velutina attacks is unknown. Here, both transcriptomic and metabolomic analyses were integrated to decipher what happened in the brain tissues of A. cerana exposed to V. velutina attacks. Transcriptomic analysis revealed 296 differentially expressed genes (DEGs) that were significantly enriched in neural signaling pathways (particularly serotonin and dopamine transmission), the cAMP signaling pathway, and energy metabolism. Metabolomic results showed that V. velutina attacks affected 38 metabolic pathways involving 86 differentially expressed metabolites (DEMs), primarily including amino acids, nucleotides, and carbohydrates. Several metabolites, such as isocitrate, xanthine, and adenosine, were upregulated in response to the hornet presence. Combined pathway analysis indicated an upregulation of the purine and tyrosine metabolism pathways, highlighting their critical role in A. cerana against invasive hornets. The results of this study will help to understand the molecular mechanisms of A. cerana in response to V. velutina attacks and provide valuable insights for enhancing collective defensive behavior against V. velutina in honeybees. Full article

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

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27 pages, 4953 KB

Open AccessArticle

Genome-Wide Analysis and Functional Correlation of Tomato JAZ Genes Under Tuta absoluta Infestation and Nanoparticle-Induced Defense

by Inzamam Ul Haq, Abdul Basit, Moazam Hyder, Mirza Naveed Shahzad, Asim Abbasi, Yasir Sharif, Muhammad Adeel Ghafar, Xiangyun Cai, Nazih Y. Rebouh and Youming Hou

Insects 2025, 16(10), 1046; https://doi.org/10.3390/insects16101046 - 13 Oct 2025

Abstract

Tomato (Solanum lycopersicum) production is increasingly threatened by Tuta absoluta, a destructive pest that compromises yield and quality. To explore sustainable alternatives to conventional insecticides, we investigated the jasmonate-mediated defense pathway by performing a genome-wide characterization of the JAZ gene [...] Read more.

Tomato (Solanum lycopersicum) production is increasingly threatened by Tuta absoluta, a destructive pest that compromises yield and quality. To explore sustainable alternatives to conventional insecticides, we investigated the jasmonate-mediated defense pathway by performing a genome-wide characterization of the JAZ gene family in S. lycopersicum. A total of 39 SlJAZ genes were identified and mapped to 12 chromosomes. Detailed analysis revealed conserved motifs, diverse exon–intron structures, four major phylogenetic groups, and the presence of multiple MeJA- and stress-responsive cis-elements. Synteny analysis indicated gene duplication events and evolutionary conservation with Arabidopsis and potato. Small RNA predictions suggested that 33 SlJAZ genes are targeted by 69 microRNAs, implying multilayered regulation. Transcriptome analysis under four treatment conditions—mesoporous silica nanoparticles (MSNs) ± pest infestation—revealed 21 differentially expressed SlJAZ genes. SlJAZ1, SlJAZ19, SlJAZ20, and SlJAZ22 were notably upregulated under the combined MSN and pest treatment, with expression patterns validated by qRT-PCR (R² = 0.92). Phenotypic assessment of leaf damage index, larval survival rate, and number of leaf mines showed reduced pest activity in MSN-treated plants. Regression analysis demonstrated significant negative correlations between expression levels of SlJAZ20, SlJAZ26, and SlJAZ29 and pest-related damage traits. These findings indicate that MSNs function as effective elicitors of JA-responsive defense in tomato and modulate the expression of specific JAZ genes linked to enhanced resistance. The study provides a valuable foundation for integrating nanotechnology with molecular defense strategies to promote sustainable pest management. Full article

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

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10 pages, 833 KB

Open AccessArticle

Behavioral Suppression and Rapid Lethality: Beauveria bassiana B4 Targets Adult Monochamus alternatus for Sustainable Management of Pine Wilt Disease

by Yaqi Zhang, Xuejie Zhang, Liudi An, Dongfeng Gong, Jinsheng Wang, Huitao Bi, Yi Zheng, Lei Cao and Shaohui Lu

Insects 2025, 16(10), 1045; https://doi.org/10.3390/insects16101045 - 12 Oct 2025

Abstract

Pine wilt disease, transmitted primarily by Monochamus alternatus (Hope, 1842) adults, causes severe ecological and economic losses globally. Conventional chemical controls face challenges of resistance and non-target toxicity. This study identified Beauveria bassiana (Bals.-Criv.) Vuill. strain B4 as a high-virulence biocontrol agent against [...] Read more.

Pine wilt disease, transmitted primarily by Monochamus alternatus (Hope, 1842) adults, causes severe ecological and economic losses globally. Conventional chemical controls face challenges of resistance and non-target toxicity. This study identified Beauveria bassiana (Bals.-Criv.) Vuill. strain B4 as a high-virulence biocontrol agent against adult M. alternatus. Laboratory bioassays compared four strains (B1–B4), with B4 exhibiting rapid lethality (LT₅₀ = 6.61 days at 1 × 10⁸ spores/mL) and low median lethal concentration (LC₅₀ = 9.63 × 10⁵ spores/mL). Critically, B4 infection induced significant behavioral suppression, including reduced appetite and mobility prior to death. In forest trials, pheromone-enhanced nonwoven fabric bags impregnated with B4 spores reduced trap catches by 66.4% within one month, with effects persisting for over a year without reapplication. The slow-release carrier system enabled continuous spore dissemination and sustained population suppression. These results demonstrate that B4’s dual action—rapid lethality and behavioral disruption—provides an effective, eco-friendly strategy for sustainable pine wilt disease management. Full article

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

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21 pages, 2715 KB

Open AccessArticle

Comparative Transcriptome Analysis of Rhynchophorus ferrugineus (Coleoptera: Curculionidae) Reveals Potential Mechanisms Involved in the Toxication and Detoxification of the External Immune Compound p-Benzoquinone Present in Oral Secretions

by Juan Chen, Yu-Chen Pu, Wen-Qing You, Ya-Nan Ji, Can-Hui Ding, Zong-Wei Zheng, Yi-Fan Wang and You-Ming Hou

Insects 2025, 16(10), 1044; https://doi.org/10.3390/insects16101044 - 11 Oct 2025

Abstract

p-Benzoquinone (PBQ), a highly toxic compound, is the main active component in larval oral secretions of red palm weevil (RPW), Rhynchophorus ferrugineus, playing critical roles in external immunity and pathogen defense. In this study, we demonstrated that pathogens effectively induce RPW larval [...] Read more.

p-Benzoquinone (PBQ), a highly toxic compound, is the main active component in larval oral secretions of red palm weevil (RPW), Rhynchophorus ferrugineus, playing critical roles in external immunity and pathogen defense. In this study, we demonstrated that pathogens effectively induce RPW larval external immune responses. On this basis, the toxicity of PBQ to third-instar larvae was determined, with poisoning symptoms observed. The differences in gene expression between larvae before and after treatment with PBQ were analyzed by transcriptome sequencing to potentially involve the mechanisms of PBQ toxicity on larvae and the mechanisms of detoxification in the infected larvae. The results indicated that PBQ exposure was associated with altered expression of chitinase (CHI) and phenoloxidase (PO) genes in RPW larvae, which not only affects the digestion and degradation of the old cuticle but also activates phenoloxidase, further oxidizing tyrosine for its conversion into DOPA and dopamine, resulting in the generation of melanin and different degrees of cuticular melanization. The transcriptional changes further suggest that RPW larvae may employ metabolic processes to counteract the external immune-active compound PBQ toxicity by regulating the expression levels of detoxifying enzyme-encoding genes, such as cytochrome P450 (CYP450), glutathione S-transferase (GST), and ATP-binding cassette transporter (ABC). Our research provides potential novel strategies for pest control by targeting insect metabolic detoxification systems. Full article

(This article belongs to the Special Issue Invasive Pests: Bionomics, Damage, and Management)

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11 pages, 1342 KB

Open AccessArticle

Drylands Under Pressure: Responses of Insect Density to Land-Use Change in a Tropical Desert

by Anshuman Pati, Indranil Paul and Sutirtha Dutta

Insects 2025, 16(10), 1043; https://doi.org/10.3390/insects16101043 - 11 Oct 2025

Abstract

Habitat alteration due to agricultural expansion and heavy livestock grazing is a major threat for open natural ecosystems (ONEs). Within the Indian Thar Desert, such land-use transformations are altering native grassland habitats, with consequential effects on insect communities that perform vital ecological functions [...] Read more.

Habitat alteration due to agricultural expansion and heavy livestock grazing is a major threat for open natural ecosystems (ONEs). Within the Indian Thar Desert, such land-use transformations are altering native grassland habitats, with consequential effects on insect communities that perform vital ecological functions and support higher trophic levels. Between 2020 and 2022, we surveyed a 641 km² area, using belt transect and visual detection methods, to quantify insect densities at the order level across different seasons. Linear mixed-effect (LME) models revealed that the orthopteran insect densities, primarily grasshoppers, were significantly higher in grasslands compared to agriculture and barren lands and were lower in the presence of livestock grazing. Orthopteran densities were higher and showed strong seasonal dependencies, likely driven by rainfall-mediated vegetation growth during monsoons. Intense grazing and agricultural expansion reduced vegetation biomass and resource availability, which affected the insect populations negatively. These research findings underscore the urgent need to implement ecologically sensitive land management practices, including sustainable grazing regimes and grassland conservation, to maintain insect biodiversity and the broader ecological network. Given the role of insects in ecosystem functioning and their importance to conservation dependent species of, such as the critically endangered Great Indian Bustard (Ardeotis nigriceps), these findings underscore the ecological significance of preserving native grassland habitats in the Thar Desert landscape. Full article

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

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13 pages, 5128 KB

Open AccessArticle

Influence of Host’s Plant Diet on Gut Microbial Communities and Metabolic Potential in Spodoptera frugiperda

by Wan-Ying Dong, Muhammad Hafeez, Sheng-Yuan Zhao, Jin-Ming Zhang, Muhammad Imran, Farman Ullah, Xiao-Wei Li and Yao-Bin Lu

Insects 2025, 16(10), 1042; https://doi.org/10.3390/insects16101042 - 10 Oct 2025

Abstract

The gut microbiota of insects, shaped by extensive coevolution, plays a crucial role in host adaptability and ecological expansion. The fall armyworm (Spodoptera frugiperda J.E. Smith), a highly polyphagous and migratory invasive pest, infests more than 350 plant species worldwide, resulting in [...] Read more.

The gut microbiota of insects, shaped by extensive coevolution, plays a crucial role in host adaptability and ecological expansion. The fall armyworm (Spodoptera frugiperda J.E. Smith), a highly polyphagous and migratory invasive pest, infests more than 350 plant species worldwide, resulting in substantial crop losses and increased reliance on pesticide applications. In this study, we employed 16S rRNA high-throughput sequencing to investigate diet-induced alternations in the gut microbial communities of larvae fed corn, rice, or an artificial diet. The results showed that diet significantly influenced microbial diversity, with rice-fed larvae exhibiting the highest richness. Firmicutes, Proteobacteria, and Cyanobacteria were the predominant bacterial phyla. Genus-level analysis revealed notable diet-dependent shifts, with Enterobacter and other genera (e.g., Ochrobactrum and Allorhizobium–Neorhizobium–Pararhizobium–Rhizobium) only detected in plant-fed groups. Additionally, current findings suggest that gut microbial genera are more prevalent when S. frugiperda larvae feed on rice plants than on corn plants or an artificial diet and are closely linked to their metabolic activities. Dominant microbial genera are expected to support essential metabolic processes and exhibit increased abundance on rice. These results indicate that the gut microbiome of S. frugiperda is diet-driven reorganization, potentially facilitating its polyphagy. This study extends the current understanding by elucidating the specific gut microbial taxa and their putative metabolic associations that are responsive to diet in S. frugiperda, thereby providing a theoretical basis for its polyphagous capability and underscoring microbiota-based strategies for sustainable pest management. Full article

(This article belongs to the Special Issue Invasive Pests: Bionomics, Damage, and Management)

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14 pages, 1815 KB

Open AccessArticle

The Defensin NldefB as a Potential Target for Brown Planthopper Control Based on the Combination of RNA Interference and Fungal Insect Pathogen

by Chen-Ping Lan, Zhi-Guo Hu, Xiao-Ping Yu and Zheng-Liang Wang

Insects 2025, 16(10), 1041; https://doi.org/10.3390/insects16101041 - 10 Oct 2025

Abstract

Defensins are a class of small cysteine-rich cationic antimicrobial peptides (AMPs) that play vital roles in immune-regulating insect–microbe interaction, offering great potential for developing pest control approaches using RNA interference (RNAi) and insect pathogens. However, the biocontrol potential of defensins from the destructive [...] Read more.

Defensins are a class of small cysteine-rich cationic antimicrobial peptides (AMPs) that play vital roles in immune-regulating insect–microbe interaction, offering great potential for developing pest control approaches using RNA interference (RNAi) and insect pathogens. However, the biocontrol potential of defensins from the destructive rice pest Nilaparvata lugens (brown planthopper, BPH) remains largely unexplored. Here, we identified and functionally characterized a defensin-encoding gene NldefB in BPH. The open reading frame (ORF) of NldefB is 315 bp in length, encoding 104 amino acids with a conserved Knot1 domain. The qRT-PCR results showed that the transcription level of NldefB went upward with the increasing developmental stages, with the highest expressions in the female adults and their fat body. The expression of NldefB was continuously induced by bacterial pathogens but exhibited a pattern of initial increase followed by a decrease when challenged by a fungal pathogen Metarhizium anisopliae. RNAi-mediated silencing of NldefB significantly decreased the host survival rate, egg production and hatchability, as well as the capability to resist fungal infection. Additionally, NldefB suppression resulted in a significant increase in microbial loads. Our findings underscored that NldefB plays essential roles in regulating host development, pathogen defense, and microbial maintenance, providing a potential target for RNAi- and microbe-mediated BPH biocontrol. Full article

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

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16 pages, 2801 KB

Open AccessArticle

Temporal Dynamics of Bacterial Communities in Ectropis grisescens Following Cryogenic Mortality

by Xinxin Zhang, Zhibo Wang, Guozhong Feng, Qiang Xiao and Meijun Tang

Insects 2025, 16(10), 1040; https://doi.org/10.3390/insects16101040 - 9 Oct 2025

Abstract

Ectropis grisescens (Lepidoptera: Geometridae) is a destructive pest in tea plantations, leading to significant economic losses through defoliation. Existing control strategies, including chemical insecticides and biological agents, are often limited by environmental concerns, resistance, and variable efficacy. Recent evidence suggests [...] Read more.

Ectropis grisescens (Lepidoptera: Geometridae) is a destructive pest in tea plantations, leading to significant economic losses through defoliation. Existing control strategies, including chemical insecticides and biological agents, are often limited by environmental concerns, resistance, and variable efficacy. Recent evidence suggests that bacteria influence insect physiology and could be leveraged for pest management, but the postmortem microbial ecology of E. grisescens remains uncharacterized. In this study, we employed 16S rRNA sequencing to investigate temporal changes in the bacterial communities of E. grisescens cadavers at 0, 7, and 21 days following cryogenic mortality. Our results indicate a time-dependent decline in microbial diversity, while species richness initially increased before subsequent reduction. The dominant endosymbiont Wolbachia gradually diminished after host death, whereas Enterobacter remained abundant. Notably, non-dominant genera including Lysinibacillus and Sporosarcina exhibited a transient increase in abundance at day 7 before reverting to control levels by day 21. This study presents the first comprehensive analysis of postmortem microbial succession in a lepidopteran system, highlighting dynamic shifts in bacterial composition and offering potential avenues for microbiome-based pest management strategies. Full article

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

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11 pages, 5596 KB

Open AccessArticle

A New Species of Orthosyntexis (Hymenoptera: Anaxyelidae) from Mid-Cretaceous Burmese Amber

by Xiao Li, Gengyun Niu and Meicai Wei

Insects 2025, 16(10), 1039; https://doi.org/10.3390/insects16101039 - 9 Oct 2025

Abstract

Anaxyelidae, a relict lineage of sawflies, are represented by a single extant species today but displayed remarkable Mesozoic diversity. Here, we describe the Orthosyntexis mascula sp. nov. from mid-Cretaceous Burmese amber. The new species can be readily distinguished by its forewing, with a [...] Read more.

Anaxyelidae, a relict lineage of sawflies, are represented by a single extant species today but displayed remarkable Mesozoic diversity. Here, we describe the Orthosyntexis mascula sp. nov. from mid-Cretaceous Burmese amber. The new species can be readily distinguished by its forewing, with a normally sized, uniformly sclerotized pterostigma; 1-Rs shorter than 1-M; cell 1M more than twice as long as wide; absence of 1r-rs; 1-Cu, distinctly shorter than 2-Cu; 3-Cu shorter than 4-Cu; 2m-cu shorter than 1m-cu; and 3rs-m twice as short as 4-M. In the hind wing, abscissa 2-M+Cu present, 1-M shorter than 2-M, crossvein m-cu absent, and cell R1 closed. Mesotibia with two apical spurs. Examination of high-resolution photographs of Kempendaja jacutensis enables a revised interpretation of its venation, confirming its placement in Anaxyelinae. Comparative analysis of syntexine taxa further reveals that variation in the forewing crossvein 1r-rs consistently corresponds with hind wing venation, suggesting that multiple evolutionary trajectories may have existed within Syntexinae. These findings not only expand the known diversity of Cretaceous Anaxyelidae but also provide new evidence for reconstructing the evolutionary history and internal diversification of Anaxyelidae. Full article

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

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12 pages, 1621 KB

Open AccessArticle

Fitness Trade-Offs and Potential Metabolic Resistance Mechanisms in Geographically Distinct Strains of Trichogramma dendrolimi: Implications for Imidacloprid Resistance Management

by Yu-Tong Li, Xiang-Xin Kong, Wu-Nan Che, Jin-Cheng Zhou, Shu-Qi Wang and Hui Dong

Insects 2025, 16(10), 1038; https://doi.org/10.3390/insects16101038 - 9 Oct 2025

Abstract

The widespread use of neonicotinoid insecticides has led to increasing resistance in non-target organisms, including the egg parasitoid Trichogramma dendrolimi, a crucial biological control agent. Film-residue bioassays on 17 geographic strains revealed striking inter-strain variability in susceptibility to imidacloprid, with mortality at [...] Read more.

The widespread use of neonicotinoid insecticides has led to increasing resistance in non-target organisms, including the egg parasitoid Trichogramma dendrolimi, a crucial biological control agent. Film-residue bioassays on 17 geographic strains revealed striking inter-strain variability in susceptibility to imidacloprid, with mortality at a discriminating dose of 0.1 mg/L ranging from 25.7% to 87%. The most tolerant (FS) and least tolerant (HA) strains were subsequently selected for evaluation of biological parameters and comparative transcriptomics. Tolerant strains (FS) showed adaptive trade-offs: extended longevity (5.47 ± 0.57 d) and emergence (93.6 ± 1.9%), but reduced fecundity (54.6 ± 4.9 eggs) compared to HA. Transcriptome analysis revealed 2115 differentially expressed genes, with GO enrichment highlighting metabolic and detoxification pathways. KEGG analysis the most enriched pathways were “Protein digestion and absorption” and “Neuroactive ligand-receptor interaction”. RT-qPCR confirmed overexpression of CYP4C1, CYP6K1, and GstS1 in FS, indicating their potential roles in metabolic resistance if present. This study presents preliminary evidence of potential fitness trade-offs and molecular mechanisms that could underly imidacloprid resistance in T. dendrolimi, which may lead to important insights for resistance monitoring and more sustainable integrated pest management strategies. Full article

(This article belongs to the Special Issue The Role of Beneficial Insects in Pest Control)

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16 pages, 9701 KB

Open AccessArticle

The Parasitoid Complex of Aleurothrixus floccosus (Hemiptera: Aleyrodidae) in the Citrus Groves of Central–Southern Italy

by Gianluca Melone, Lucia Andretta, Valentino Maria Guastaferro, Eleonora Romito, Giorgio Formisano, Massimo Giorgini and Stefania Laudonia

Insects 2025, 16(10), 1037; https://doi.org/10.3390/insects16101037 - 9 Oct 2025

Abstract

The woolly whitefly, Aleurothrixus floccosus, is likely a Neotropical origin species that has spread globally. Introduced to France in 1969, it became a pest in southern European citrus groves, first reported in Italy in 1974. Integrated management using biological control agents is [...] Read more.

The woolly whitefly, Aleurothrixus floccosus, is likely a Neotropical origin species that has spread globally. Introduced to France in 1969, it became a pest in southern European citrus groves, first reported in Italy in 1974. Integrated management using biological control agents is crucial due to the low efficacy of chemical controls. Nymphs produce waxy filaments and honeydew, limiting insecticide contact. Natural enemies, especially from Neotropics, have been documented. The parasitoids Amitus spiniferus and Cales noacki were released in France in 1970 and later observed in Liguria, Italy. In the Campania region, C. noacki was first found on Aleurotuba jelineki in 1984 and this finding preceded the first report of A. floccosus in the same area. Subsequently, C. noacki was also introduced in other regions where it showed better adaptation throughout the Italian territory, reaching high parasitization levels on the woolly whitefly nymphs. After many years since the last field investigations, surveys in 2024–2025 in organic citrus groves in central and southern Italy identified additional parasitoids. Besides C. noacki and A. spiniferus, Eretmocerus paulistus and Signiphora xanthographa were found for the first time in Italy. Both species were originally described from the Neotropical ecozone. The aphelinid finding represents its first documented establishment in Italy, while the signiphorid one represents a new record for the European fauna. E. paulistus is a primary parasitoid, while S. xanthographa is a hyperparasitoid that can limit the effectiveness of other parasitoids. The interaction of these parasitoids resulted in high parasitism rates for A. floccosus nymphs. Preserving the current complexity of parasitoids in integrated pest management (IPM) programs could effectively control the woolly whitefly in central and southern Italy. Full article

(This article belongs to the Special Issue Insects Ecology and Biological Control Applications)

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20 pages, 2101 KB

Open AccessArticle

Culicidae Fauna (Diptera: Culicomorpha) of the Municipality of Mazagão, Amapá, in the Brazilian Amazon

by Rafael Espíndola do Nascimento, Daniel Damous Dias, Bruna Lais Sena do Nascimento, Tiago Silva da Costa, Raimundo Nonato Picanço Souto, Livia Medeiros Neves Casseb, Joaquim Pinto Nunes Neto and Valeria Lima Carvalho

Insects 2025, 16(10), 1036; https://doi.org/10.3390/insects16101036 - 9 Oct 2025

Abstract

The Amazon hosts one of the richest diversities of mosquitoes in the family Culicidae, which are key both as arbovirus vectors and as environmental bioindicators. However, the state of Amapá remains poorly studied regarding its mosquito fauna. This study aimed to characterize the [...] Read more.

The Amazon hosts one of the richest diversities of mosquitoes in the family Culicidae, which are key both as arbovirus vectors and as environmental bioindicators. However, the state of Amapá remains poorly studied regarding its mosquito fauna. This study aimed to characterize the diversity and seasonal composition of Culicidae in the municipality of Mazagão, Eastern Amazon, within a rural landscape influenced by human activity and extreme climatic events. Three sampling campaigns were conducted between 2023 and 2024, covering rainy, intermediary, and dry periods. Mosquitoes were collected using Protected Human Attraction (PHA) and CDC light traps at both ground and canopy strata. A total of 3500 specimens were obtained, representing 38 species across 15 genera. The intermediary period yielded the highest abundance and richness, whereas the dry season presented very low diversity, probably because of severe drought and forest fires. Dominant species included Coquillettidia (Rhy.) venezuelensis, Cq. albicosta, and Mansonia titillans. There were significant differences in community diversity between dry and wetter periods, underscoring the strong role of seasonality in shaping mosquito populations. These findings represent the entomofaunistic survey of the region, contributing to biodiversity knowledge and highlighting potential public health risks, thus reinforcing the need for continuous entomological monitoring. 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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13 pages, 1714 KB

Open AccessArticle

Mating Disruption with Biodegradable Dispensers Complemented with Insecticide Sprays Allows an Effective Management of Tuta absoluta in Greenhouse Tomatoes

by Luigi Sannino, Giovanni Benelli, Giulio Piccirillo, Angelo Canale and Andrea Lucchi

Insects 2025, 16(10), 1035; https://doi.org/10.3390/insects16101035 - 9 Oct 2025

Abstract

IPM approaches based on pheromone-based techniques for the management of the South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), are of great interest. We evaluated the effectiveness of mating disruption (MD) experiments against T. absoluta using a biodegradable pheromone dispenser (Isonet-T TT [...] Read more.

IPM approaches based on pheromone-based techniques for the management of the South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), are of great interest. We evaluated the effectiveness of mating disruption (MD) experiments against T. absoluta using a biodegradable pheromone dispenser (Isonet-T TT BIOX234) in greenhouse-grown tomatoes over two years in southern Italy. A base treatment alternating the most used insecticides for the pest, i.e., the farmer treatment schedule (FTS), was assigned as a reference, and two MD dispenser densities (i.e., 300 and 500 dispensers/ha) were compared with the MD commercial product Isonet T at 1000 units/ha. We conducted two trials on crops at a density of 37,000 plants/ha. Pest flights were monitored in summer–autumn 2023 and 2024 with pheromone-baited Delta traps. The FTS ensured a generally low level of T. absoluta attacks (about 1 leaflet/leaf and 1/300 fruits). Even so, mating disruption resulted in further appreciable reductions in the presence and attacks of the target pest: 89%, 76% and 52% fewer catches; 61%, 45% and 37% fewer mined leaflets; and 76%, 59% and 54% fewer attacked fruits, for Isonet-T TT 500, Isonet-T TT 300 and Isonet T 1000, respectively. Overall, MD biodegradable dispensers could be a valuable tool for controlling T. absoluta in greenhouse-grown tomatoes, while also reducing plastic waste in the agricultural setting. Full article

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

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31 pages, 15340 KB

Open AccessArticle

Integrative Description and Redescription of Black Fly (Diptera: Simuliidae) Species in the Simulium (Gomphostilbia) ceylonicum Species-Group from Thailand

by Sorawat Thongsahuan, Kittipat Aupalee, Afham Yakoh, Domechai Kaewnoi, Wanchai Maleewong, Wichai Srisuka, Anchalee Wannasan, Atiporn Saeung and Hiroyuki Takaoka

Insects 2025, 16(10), 1034; https://doi.org/10.3390/insects16101034 - 8 Oct 2025

Abstract

Utilizing the COI barcoding approach, cryptic diversity has previously been detected within the morphologically recognized Simulium (Gomphostilbia) trangense Jitklang, Kuvangkadilok, Baimai, Takaoka & Adler, 2008 and S. (G.) sheilae Takaoka & Davies, 1995, of the S. (G.) [...] Read more.

Utilizing the COI barcoding approach, cryptic diversity has previously been detected within the morphologically recognized Simulium (Gomphostilbia) trangense Jitklang, Kuvangkadilok, Baimai, Takaoka & Adler, 2008 and S. (G.) sheilae Takaoka & Davies, 1995, of the S. (G.) ceylonicum species-group. Here, an unknown black fly species belonging to the S. ceylonicum species-group from southern Thailand was discovered and described as a new species, S. (G.) sipoense sp. nov. In addition, S. (G.) trangense is herein fully redescribed based on specimens collected from its type locality. Based on an integrative taxonomic approach combining morphological and molecular data, the validity of the newly described S. sipoense sp. nov. and the redescribed S. trangense is confirmed. Comparative morphological characteristics and phylogenetic analysis, inferred from COI sequences, suggest that the new species is conspecific with the species redescribed as S. trangense, using specimens collected from Malaysia, and is morphologically and phylogenetically closely related to S. sheilae, particularly to the specimens from Indonesia. The redescribed S. trangense is genetically highly similar or even identical to the species that was apparently misidentified as S. sheilae from southern and western Thailand, and is morphologically very similar to the new species, from which it is clearly distinguished by the relative length of the female claw tooth, shape of the male ventral plate, and color of the larval body. A detailed information on the morphological characteristics separates the new species, and the redescribed S. trangense from all other known species of the same species-group in Thailand and neighboring countries is provided. Further studies are warranted to clarify the taxonomic status of several cryptic species recognized within the morphologically defined S. trangense and S. sheilae. Full article

(This article belongs to the Special Issue Diptera Diversity: Systematics, Phylogeny and Evolution)

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31 pages, 10340 KB

Open AccessArticle

Silencing the cyp314a1 and cyp315a1 Genes in the Aedes albopictus 20E Synthetic Pathway for Mosquito Control and Assessing Algal Blooms Induced by Recombinant RNAi Microalgae

by Xiaodong Deng, Changhao He, Chunmei Xue, Dianlong Xu, Juncai Li and Xiaowen Fei

Insects 2025, 16(10), 1033; https://doi.org/10.3390/insects16101033 - 7 Oct 2025

Abstract

As one of the key vectors for the transmission of Dengue fever, Aedes albopictus is highly ecologically adaptable. The development of environmentally compatible biological defence and control technologies has therefore become an urgent need for vector biological control worldwide. This study constructed and [...] Read more.

As one of the key vectors for the transmission of Dengue fever, Aedes albopictus is highly ecologically adaptable. The development of environmentally compatible biological defence and control technologies has therefore become an urgent need for vector biological control worldwide. This study constructed and used double-stranded RNA (dsRNA) expression vectors targeting the cyp314a1 and cyp315a1 genes of Ae. albopictus to transform Chlamydomonas reinhardtii and Chlorella vulgaris, achieving RNA interference (RNAi)-mediated gene silencing. The efficacy of the RNAi recombinant algal strain biocide against Ae. albopictus was evaluated by administering it to Ae. albopictus larvae. The results showed that the oral administration of the cyp314a1 and cyp315a1 RNAi recombinant C. reinhardtii/C. vulgaris strains was lethal to Ae. albopictus larvae and severely affected their pupation and emergence. The recombinant algal strains triggered a burst of ROS (Reactive Oxygen Species) in the mosquitoes’ bodies, resulting in significant increases in the activities of the superoxide dismutase (SOD), peroxiredoxin (POD) and catalase (CAT), as well as significant upregulation of the mRNA levels of the CME pathway genes in larvae. In the simulated field experiment, the number of Ae. albopictus was reduced from 1000 to 0 in 16 weeks by the RNAi recombinant Chlorella, which effectively controlled the population of mosquitoes. Meanwhile, the levels of nitrogen (N), phosphorus (P), nitrate, nitrite, ammonia and COD (Chemical Oxygen Demand) in the test water decreased significantly. High-throughput sequencing analyses of 18S rDNA and 16S rDNA showed that, with the release of RNAi recombinant Chlorella into the test water, the biotic community restructuring dominated by resource competition caused by algal bloom, as well as the proliferation of anaerobic bacteria and the decline of aerobic bacteria triggered by anaerobic conditions, are the main trends in the changes in the test water. This study is an important addition to the use of RNAi recombinant microalgae as a biocide. Full article

(This article belongs to the Special Issue RNAi in Insect Physiology)

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17 pages, 1534 KB

Open AccessArticle

Improving Telenomus remus (Hymenoptera: Scelionidae) Adoption: Contribution of Different Egg Parasitoid Densities, Fed Adults, and Their Storage for Successful Biological Control of Spodoptera frugiperda (Lepidoptera: Noctuidae)

by Weidson P. Sutil, Adeney de F. Bueno, Leonardo Roswadoski, Rafael S. Iasczczaki, Gabriel S. Carneiro and Yelitza C. Colmenarez

Insects 2025, 16(10), 1032; https://doi.org/10.3390/insects16101032 - 6 Oct 2025

Abstract

Egg parasitoids, such as Telenomus remus (Hymenoptera: Scelionidae), face significant challenges after release, as their pupae are exposed to various mortality factors that reduce the efficiency of biological control programs. Therefore, this study aimed to evaluate a honey-solid diet that can feed adults [...] Read more.

Egg parasitoids, such as Telenomus remus (Hymenoptera: Scelionidae), face significant challenges after release, as their pupae are exposed to various mortality factors that reduce the efficiency of biological control programs. Therefore, this study aimed to evaluate a honey-solid diet that can feed adults still inside the capsules without sticking the wasps on its surface, enabling parasitoid storage and later field release. Three independent bioassays were performed, each with 20 completely randomized replications. The first bioassay evaluated the acceptance of a solid feed—honey soaked in cotton thread—compared to the traditional form—honey droplets. In the second bioassay, the storage periods after emergence of adults in capsules with honey-solid food were analyzed at 2, 4, 6, and 8 days post-emergence, and the third bioassay studied the efficacy of different release densities of fed adults under field conditions. Parasitoids fed on the honey-solid diet exhibited a 13.3% reduction in parasitism compared to honey droplets. However, the sticky, viscous nature of honey can lead to parasitoids becoming glued, potentially leading to their death. T. remus feeding on the honey-solid diet resulted in low mortality inside the capsules, living up to six days with only 22.2% reduction in parasitism capacity, making it a viable alternative to release and transport fed adult parasitoids, with an increase of around 30% in the released density of parasitoids compared with the parasitoids fed on honey droplets. This flexibility of releasing T. remus up to six days after emergence provided valuable knowledge to establish T. remus as a biocontrol agent. Furthermore, the highest tested parasitoid density of 20,000 parasitoids per hectare obtained the highest parasitism of Spodoptera frugiperda (Lepidoptera: Noctuidae) eggs. However, future studies are still required with higher releasing densities and less expensive methods of mass rearing the parasitoid for those higher densities to be economically viable. Full article

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

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