Insects

13 pages, 512 KB

Open AccessArticle

Synergistic Effects of Beauveria bassiana and Insecticides for Integrated Management of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)

by Xiaole Wang, Yunfei Li, Yuping Zha, Yubin Tian, Jing Wang, Hanbing Li, Zhihui Zhu and Wanlun Cai

Insects 2025, 16(10), 1067; https://doi.org/10.3390/insects16101067 (registering DOI) - 19 Oct 2025

Abstract

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is a significant agricultural pest that causes substantial economic losses globally. While chemical insecticides are commonly used for its management, increasing resistance and environmental concerns underscore the need for alternative control strategies. This study evaluated the potential of [...] Read more.

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is a significant agricultural pest that causes substantial economic losses globally. While chemical insecticides are commonly used for its management, increasing resistance and environmental concerns underscore the need for alternative control strategies. This study evaluated the potential of integrating the entomopathogenic fungus Beauveria bassiana strain Bb-33 (Hypocreales: Clavicipitaceae) with reduced doses of chemical insecticides for sustainable B. dorsalis management. The compatibility of B. bassiana Bb-33 with six commonly used insecticides—spinosad, emamectin benzoate, avermectin, thiamethoxam, beta-cypermethrin, and imidacloprid—was assessed. Among them, emamectin benzoate exhibited the least inhibitory effects on spore germination, mycelial growth, and sporulation of B. bassiana. Laboratory bioassays demonstrated synergistic interactions between B. bassiana Bb-33 and emamectin benzoate, particularly when the ratio of emamectin benzoate to B. bassiana exceeded 4:1, as indicated by co-toxicity coefficients greater than 100. However, greenhouse trials revealed that the combined formulation had lower efficacy in reducing B. dorsalis adult populations and pupal emergence rates compared to emamectin benzoate alone, though it was more effective than B. bassiana Bb-33 applied independently. Importantly, this composite formula reduces pesticide usage, which highlights its potential to mitigate environmental impacts. This study underscores the promise of integrating B. bassiana Bb-33 with reduced doses of emamectin benzoate as a viable strategy for managing B. dorsalis. Despite its current limitations in greenhouse trials, further optimization of formulation stability and application methods could enhance its field performance, offering an effective and environmentally friendly alternative to conventional chemical control methods. Full article

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

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13 pages, 888 KB

Open AccessArticle

Diet-Driven Variations in Longevity and Fecundity of the Endangered Tiger Beetle Cicindela anchoralis (Coleoptera: Carabidae)

by Deokjea Cha, Anya Lim and Jong-Kook Jung

Insects 2025, 16(10), 1066; https://doi.org/10.3390/insects16101066 (registering DOI) - 18 Oct 2025

Abstract

Diet is a key factor modulating the trade-off between fecundity and longevity, a cornerstone of life-history theory. While laboratory studies have demonstrated that high-protein-to-carbohydrate (P:C) ratio diets increase reproductive output at the cost of lifespan, it remains unclear how this trade-off operates in [...] Read more.

Diet is a key factor modulating the trade-off between fecundity and longevity, a cornerstone of life-history theory. While laboratory studies have demonstrated that high-protein-to-carbohydrate (P:C) ratio diets increase reproductive output at the cost of lifespan, it remains unclear how this trade-off operates in species exposed to natural dietary variability and prey choice. We tested whether diet-mediated trade-offs between fecundity and longevity are modulated by prey-insect type in the endangered tiger beetle, Cicindela anchoralis, a species with a short adult lifespan. Tiger beetles were offered a choice between a high-P:C diet (cricket) and low-P:C diet (ant). Tiger beetles consuming the high-P:C diet exhibited increased fecundity and reduced longevity, while those feeding on the low-P:C diet showed the opposite pattern. Despite these consequences, both sexes showed a consistent preference for the high-P:C diet, suggesting that beetles prioritize reproductive output over lifespan. These results suggest that prey-insect selection might be an adaptive way to boost reproductive success within a limited adult lifespan, which may raise tiger beetles’ intrinsic rate of natural increase. Our findings highlight the ecological relevance of diet-driven life-history trade-offs and offer practical guidance for mass propagation strategies to support endangered tiger beetle recovery. Full article

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

13 pages, 2670 KB

Open AccessArticle

Liu-pao Tea as a Source of Botanical Oviposition Attractants for Aedes Mosquitoes

by Li-Hua Xie, Tong Liu, Wen-Qiang Yang, Yu-Gu Xie, Si-Yu Zhao and Xiao-Guang Chen

Insects 2025, 16(10), 1065; https://doi.org/10.3390/insects16101065 - 17 Oct 2025

Abstract

Oviposition attractants can enhance both the surveillance and control of container-breeding Aedes mosquitoes. Although green tea has been reported to attract Ae. aegypti, the specific bioactive botanical compounds responsible remain unidentified. We evaluated teas across fermentation stages (non-fermented, fully fermented, and post-fermented) [...] Read more.

Oviposition attractants can enhance both the surveillance and control of container-breeding Aedes mosquitoes. Although green tea has been reported to attract Ae. aegypti, the specific bioactive botanical compounds responsible remain unidentified. We evaluated teas across fermentation stages (non-fermented, fully fermented, and post-fermented) at 5 g/L for gravid Ae. albopictus using dual-choice assays. The most attractive tea (Liu-pao) was further tested across concentrations (0.5–5 g/L) and infusion ages (1–28 days). Autoclaved vs. non-autoclaved infusions assessed microbial contributions, while headspace volatiles were analyzed via HS-SPME-GC-MS. Individual compounds (cedrol and linalool oxide) were bioassayed. Only Liu-pao tea consistently attracted Ae. albopictus (OAI ≥ 0.3), peaking at 5 g/L after 7–14 days (OAIs 0.73/0.67). A 0.5 g/L infusion aged 21–28 days also attracted Ae. aegypti (OAIs 0.89/0.63). Autoclaving did not reduce attraction, confirming volatile compounds, not live microbe-mediated effects. Cedrol (1 mg/L) elicited moderate attraction (OAI 0.29) in Ae. albopictus, while linalool oxide was inactive. Post-fermented Liu-pao tea acts as a potent botanical attractant for Aedes mosquitoes. Cedrol contributes partially, but whole tea infusions outperform single compounds. These findings support developing multi-volatile “attract-and-kill” strategies targeting gravid mosquitoes. 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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14 pages, 1818 KB

Open AccessArticle

The Mitochondrial Hsp90 Homolog PmTRAP1 Mediates Thermal Tolerance in the Papaya Mealybug, Paracoccus marginatus

by Yanting Chen, Xiaomin Zhao, Chenyu Lv, Jianwei Zhao, Mengzhu Shi, Jianwei Fu and Jianyu Li

Insects 2025, 16(10), 1064; https://doi.org/10.3390/insects16101064 - 17 Oct 2025

Abstract

The papaya mealybug, Paracoccus marginatus, a significant invasive pest in tropical and subtropical regions, exhibits a notable capacity to withstand high-temperature stress. To elucidate the molecular basis of this thermotolerance, we investigated the role of heat shock protein 90 (Hsp90) genes in [...] Read more.

The papaya mealybug, Paracoccus marginatus, a significant invasive pest in tropical and subtropical regions, exhibits a notable capacity to withstand high-temperature stress. To elucidate the molecular basis of this thermotolerance, we investigated the role of heat shock protein 90 (Hsp90) genes in this species. The full-length cDNA sequences of three Hsp90 genes—PmHsp90-1, PmHsp90-2, and PmTRAP1—were cloned, subjected to bioinformatic analysis, and their expression profiles under heat stress were detected. RNAi-mediated suppression of PmTRAP1 was conducted to evaluate survival under extreme high-temperature conditions. The open reading frames (ORFs) of PmHsp90-1, PmHsp90-2, and PmTRAP1 are 2175 bp, 2178 bp, and 2085 bp in length, encoding proteins comprising 724, 725, and 694 amino acids, respectively. Phylogenetic and structural analyses confirmed that PmHsp90-1 and PmHsp90-2 are cytosolic isoforms, each containing a characteristic C-terminal MEEVD motif, while PmTRAP1 was identified as the mitochondrial isoform. All three genes were significantly upregulated under heat stress. RNAi-mediated knockdown of PmTRAP1 markedly reduced the survival rate of P. marginatus under extreme high temperature. These findings demonstrate that PmTRAP1 is essential for heat tolerance in the papaya mealybug. This study provides crucial insights into the molecular mechanisms of thermal adaptation in insects and identifies PmTRAP1 as a potential target for future research on managing insect responses to environmental stress. Full article

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

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11 pages, 1599 KB

Open AccessArticle

Polyandry in Noctuid Moths: Taxonomic, Bionomic, and Evolutionary Implications

by Zoltán Varga, Antal Nagy, Csenge Lelle Kovács and Szabolcs Szanyi

Insects 2025, 16(10), 1063; https://doi.org/10.3390/insects16101063 - 17 Oct 2025

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Abstract

Polyandry influences sexual behaviour and supports sexual selection in moths, incl. Noctuids. In polyandry, a female mates with multiple males within a few days. Copulation is a multi-phase process, as sperm are packed into spermatophores and transferred to the female genitalia. This process [...] Read more.

Polyandry influences sexual behaviour and supports sexual selection in moths, incl. Noctuids. In polyandry, a female mates with multiple males within a few days. Copulation is a multi-phase process, as sperm are packed into spermatophores and transferred to the female genitalia. This process is costly, since spermatophore production and transfer is time-consuming. When this process is repeated, it results in sexual selection and enhances heterozygosity. Pest and migrating Noctuids are often polyandrous. Polyandry is common in the “pest clade” of Noctuidae (e.g., Euxoa, Dichagyris). We hypothesised that the asymmetric allocation of sensory and stimulating functions on the genitalia enhance sexual selection and promote speciation. In polyandrous species of the subtribe Poliina, we show that the evolution of the secondary asymmetry of male external genitalia is connected to an increase in species diversity. Some species inhabiting temperate forests were found to be moderately (Orthosia) or highly (Conistra) polyandrous, in connection with their different life cycles and despite similar reproductive timing. Based on fecundity data of some common species, we hypothesised that habitat generalists should be more polyandrous than habitat specialists. However, our data are insufficient to determine whether ecology and/or phylogeny influence the level of polyandry. Other factors, such as the connection between the sex ratio and the level of polyandry, should be surveyed in future studies, considering their relevance to plant protection. Full article

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

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17 pages, 1527 KB

Open AccessArticle

Intergenerational Effects of Gamma Radiation on Biology and Transcriptome of Invasive Tomato Leaf Miner, Tuta absoluta

by Yuhan Pan, Haixia Zhang, Qinghe Zhang, Farman Ullah, Yiming Pan, Yaru Wang, Limin Chen, Xiaowei Li, Jinming Zhang, Shuxing Zhou, Yaobin Lu and Youming Hou

Insects 2025, 16(10), 1062; https://doi.org/10.3390/insects16101062 - 17 Oct 2025

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Abstract

The tomato leaf miner, Tuta absoluta, is a major pest affecting economically important crops like tomatoes, causing significant global economic losses and exhibiting increasing resistance to pesticides. The sterile insect technique (SIT) is an environmentally friendly control method that is sustainable for [...] Read more.

The tomato leaf miner, Tuta absoluta, is a major pest affecting economically important crops like tomatoes, causing significant global economic losses and exhibiting increasing resistance to pesticides. The sterile insect technique (SIT) is an environmentally friendly control method that is sustainable for both ecosystems and human health. This study used age-stage, two-sex life tables, transcriptomics, and bioinformatics to analyze how irradiation affects the reproductive capacity of male T. absoluta. Compared to the control group, the irradiated offspring showed reduced total lifespan, pre-adult survival rate, net reproductive rate, and intrinsic growth rate. Transcriptomic analysis identified 232 differentially expressed genes (DEGs). GO and KEGG enrichment analyses revealed that irradiation impacted biological processes in male adults related to key biomolecules, hormone metabolism and synthesis, and immune responses. Of the 14 selected genes validated through RT-qPCR, 13 were identified as potential regulators of male reproductive capacity, offering possible targets for controlling T. absoluta using inherited sterility-based SIT strategies. Overall, this study provides a theoretical basis for applying SIT in field control and identifies potential genetic targets for managing T. absoluta populations through a genetic sterile insect technique. Full article

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

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14 pages, 578 KB

Open AccessSystematic Review

Systematic Review of Variable Selection Bias in Species Distribution Models for Aedes vexans (Diptera: Culicidae)

by Peter Pothmann, Helge Kampen, Doreen Werner and Hans-Hermann Thulke

Insects 2025, 16(10), 1061; https://doi.org/10.3390/insects16101061 - 17 Oct 2025

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Abstract

We conducted a systematic literature review, following PRISMA guidelines, to assess whether existing species distribution models for Aedes vexans reflect its known ecological requirements. This mosquito is closely associated with temporary floodwaters, making hydrological dynamics a critical factor for accurate modelling. From 28 [...] Read more.

We conducted a systematic literature review, following PRISMA guidelines, to assess whether existing species distribution models for Aedes vexans reflect its known ecological requirements. This mosquito is closely associated with temporary floodwaters, making hydrological dynamics a critical factor for accurate modelling. From 28 peer-reviewed studies, we extracted 477 environmental and ecological variables and organized them into a hierarchical classification scheme with four main categories: weather, land characteristics, water characteristics, and population. We analysed patterns in variable usage and the reported importance of each variable. Our results show that flood-related variables were largely absent, despite the species’ reliance on ephemeral water bodies for reproduction. This may possibly reduce the predictive utility of existing Aedes vexans species distribution models. In contrast, urban-landscape variables were frequently used and often ranked as highly predictive, but such results were primarily found in studies that did not account for sampling bias. Full article

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

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39 pages, 17068 KB

Open AccessArticle

Synopsis of Ant Genus Proceratium Roger, 1863 from China (Hymenoptera, Formicidae), with Description of Seven New Species

by Zhuojian Gu, Chen Zhang and Zhilin Chen

Insects 2025, 16(10), 1060; https://doi.org/10.3390/insects16101060 - 17 Oct 2025

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Abstract

The genus Proceratium comprises rare but ecologically significant cryptobiotic predators of temperate and tropical forest litter. The group is known for its abdomen which can curl dorsally >90° relative to the body axis. Proceratium includes 130 described species worldwide. In China, seven species [...] Read more.

The genus Proceratium comprises rare but ecologically significant cryptobiotic predators of temperate and tropical forest litter. The group is known for its abdomen which can curl dorsally >90° relative to the body axis. Proceratium includes 130 described species worldwide. In China, seven species have been recorded, yet recent surveys repeatedly reveal morphologically distinctive undescribed taxa, indicating a still-underestimated diversity of Proceratium. In this study, seven known Chinese species of the ant genus Proceratium Roger, 1863 are reviewed: P. bruelheidei, P. itoi, P. japonicum, P. kepingmai, P. longmenense, P. shohei and P. zhaoi. The species P. longigaster is removed from the ant fauna of China. Additionally, seven new species are described: P. crassopetiolum sp. nov., P. digitospinum sp. nov., P. planodorsum sp. nov., P. quandratinodum sp. nov., P. rugiceps sp. nov., P. shanyii sp. nov., and P. spinosubum sp. nov. An illustrated key to Chinese species based on workers is also provided. Full article

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

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17 pages, 1808 KB

Open AccessArticle

Selection Behavior of the Beet Armyworm, Spodoptera exigua (Hübner) Between Bt Maize and Conventional Maize Plants

by Cheng Song, Xianming Yang, Guodong Kang, Limei He, Wenhui Wang, Xiang Han, Yujiao Xie and Kongming Wu

Insects 2025, 16(10), 1059; https://doi.org/10.3390/insects16101059 - 17 Oct 2025

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Abstract

Establishing refuges is a primary strategy for managing resistance in target pests against Bt maize. The larval feeding and dispersal, and adult oviposition behaviors of Spodoptera exigua (Hübner) on Bt and non-Bt maize plants are critical factors in determining optimal refuge configurations. This [...] Read more.

Establishing refuges is a primary strategy for managing resistance in target pests against Bt maize. The larval feeding and dispersal, and adult oviposition behaviors of Spodoptera exigua (Hübner) on Bt and non-Bt maize plants are critical factors in determining optimal refuge configurations. This study employed laboratory and field experiments to evaluate the larval feeding and dispersal behaviors, as well as the oviposition preferences of S. exigua moths, on Bt (Cry1Ab + Vip3Aa19) and non-Bt maize plants. Results showed that as time of the choice test increased, the larval selection rate on Bt maize leaves declined progressively, with all instars (1st–5th) preferring to feed on non-Bt maize. After 48 h, the selection rates of larvae for non-Bt and Bt maize were 40.63–66.25% and 9.38–33.75%, respectively. Female moths exhibited no significant oviposition preference between Bt and non-Bt plants under undamaged conditions; however, when non-Bt maize was infested by the larvae, females preferentially oviposited on Bt maize plants (73.55%). Under the seed-mixture refuge pattern in field conditions, increasing the proportion of non-Bt maize significantly enhanced larval dispersal distances and facilitated larval transit damage between Bt and non-Bt plants. Our research clarifies the behavioral patterns of S. exigua on Bt and non-Bt maize, provides a scientific basis for optimizing refuge strategy to delay the development of resistance. Full article

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

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18 pages, 1618 KB

Open AccessArticle

Impact of Biogenic Structures of the Soil-Nesting Ants Lasius niger and Lasius flavus on the Soil Microarthropod Community in Urban Green Spaces

by Maria Sterzyńska, Dariusz J. Gwiazdowicz, Paweł Nicia, Paweł Zadrożny, Gema Trigos-Peral and Mohamed W. Negm

Insects 2025, 16(10), 1058; https://doi.org/10.3390/insects16101058 - 17 Oct 2025

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Abstract

Organisms that physically modify their environment, known as ecosystem engineers, can influence resource availability, species interactions and the structure of soil communities. However, the specific effect of ecosystem engineers like ants on the abundance and diversity of non-engineering soil organisms remains understudied. To [...] Read more.

Organisms that physically modify their environment, known as ecosystem engineers, can influence resource availability, species interactions and the structure of soil communities. However, the specific effect of ecosystem engineers like ants on the abundance and diversity of non-engineering soil organisms remains understudied. To address this knowledge gap, we conducted a survey of a multi-taxon belowground community of soil microarthropods—Collembola, Mesostigmata, Oribatida and Actinedida—in urban areas, comparing nest mounds of the ant species Lasius niger and Lasius flavus with areas without ant-nesting activity (control). We hypothesised differences in abundance and distribution patterns of different soil microarthropod taxa between ant mounds and the control soil. We also hypothesised that ant-induced soil disturbance is species-specific, and may result in different patterns of diversity and composition of soil microarthropod assemblages within trophic levels, such as among detritivores (e.g., Collembola) and predators (e.g., Mesostigmata). Our results reveal how ecological filters shape different soil microarthropod groups’ responses to ant-driven changes in their environment. As we expected, soil disturbance caused by ant nest-building activity significantly influenced the abundance, distribution patterns and diversity of soil microarthropods, especially in the assembly of detritivorous—but not predatory—guilds of soil microarthropods. Full article

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

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16 pages, 2210 KB

Open AccessArticle

Spatial and Temporal Distribution of Mosquito Species (Culicidae) in a Ramsar Site, Fetzara Lake (Annaba, Algeria)

by Amna Rouibi, Abdelhakim Rouibi and Rassim Khelifa

Insects 2025, 16(10), 1057; https://doi.org/10.3390/insects16101057 - 16 Oct 2025

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Abstract

Mosquito community composition can differ spatially and temporally within the same wetlands. Understanding this spatiotemporal variation is crucial, particularly in wetlands of conservation importance. Here, we examine the diversity and community composition of Culicidae (Diptera) across four sites within Fetzara Lake, a large [...] Read more.

Mosquito community composition can differ spatially and temporally within the same wetlands. Understanding this spatiotemporal variation is crucial, particularly in wetlands of conservation importance. Here, we examine the diversity and community composition of Culicidae (Diptera) across four sites within Fetzara Lake, a large Ramsar site in Northeast Algeria. For two years, we conducted monthly field surveys across four sites (Northeast, Northwest, Southeast, and Southwest) from April 2021 to March 2023. During these surveys, we used ovitraps to sample mosquitoes and assess species richness as well as alpha and beta diversity. We identified seven mosquito species (Aedes aegypti, Ae. albopictus, Ae. geniculatus, An. labranchiae, Culex perexiguus, Cx. pipiens, and Cs. longiareolata). There was a clear dominance of Culex pipiens (Usutu and West Nile virus vector), which accounted for 74.3% of all samples, whereas Aedes aegypti was the least abundant (<1%). Species richness varied between five and six across sites. The Shannon index and beta diversity revealed significant variation in species diversity across sites and seasons, likely driven by local differences in environmental conditions. This study emphasizes the importance of local variation in environmental conditions in shaping ecological communities in space and time. Full article

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

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18 pages, 3373 KB

Open AccessArticle

A DNA Barcode Inventory of Austrian Dragonfly and Damselfly (Insecta: Odonata) Species

by Lukas Zangl, Iris Fischer, Marcia Sittenthaler, Andreas Chovanec, Patrick Gros, Werner Holzinger, Gernot Kunz, Andrea Lienhard, Oliver Macek, Christoph Mayerhofer, Marija Mladinić, Martina Topić, Sylvia Schäffer, Kristina M. Sefc, Christian Sturmbauer, Elisabeth Haring and Stephan Koblmüller

Insects 2025, 16(10), 1056; https://doi.org/10.3390/insects16101056 - 16 Oct 2025

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Abstract

Dragonflies and damselflies are important indicator species for quality and health of (semi-)aquatic habitats. Hitherto, 78 species of Odonata have been reported for Austria. Ecological data, Red List assessments, and a dragonfly association index exist, but population- and species-level genetic data are largely [...] Read more.

Dragonflies and damselflies are important indicator species for quality and health of (semi-)aquatic habitats. Hitherto, 78 species of Odonata have been reported for Austria. Ecological data, Red List assessments, and a dragonfly association index exist, but population- and species-level genetic data are largely lacking. In this study, we establish a comprehensive reference DNA barcode library for Austrian dragonflies and damselflies based on the standard barcoding marker COI. Because of the increasing significance of environmental DNA (eDNA) analyses, we also sequenced a segment of the mitochondrial 16S rRNA gene, a marker often used in eDNA metabarcoding approaches. In total, we provide 786 new COI barcode sequences and 867 new 16S sequences for future applications. Sequencing success was >90 percent for both markers. Identification success was similar for both markers and exceeded 90 percent. Difficulties were only encountered in the genera Anax Leach, 1815, Chalcolestes Kennedy, 1920, Coenagrion Kirby, 1890 and Somatochlora Selys, 1871, with low interspecific genetic distances and, consequently, BIN (barcode index number) sharing. In Anax, however, individual sequences clustered together in species-specific groups in the COI tree. Irrespective of these challenges, the results suggest that both markers perform well within most odonate families in terms of sequencing success and species identification and can be used for reliably delimiting Austrian species, monitoring, and eDNA approaches. Full article

(This article belongs to the Special Issue Aquatic Insects: Ecology, Diversity and Conservation)

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13 pages, 3835 KB

Open AccessArticle

Biological Characteristics and Bacterial Community of Invasive Pest Corythucha ciliata (Hemiptera: Tingidae)

by Tong-Pu Li, Bing-Ren Hao, Chen-Hao Wang, Jing-Jing Xu, Xiao-Tong Wang, Jia-Chu Xie, Zhi-Heng Wang, Shu-Cheng Ye and Lv-Quan Zhao

Insects 2025, 16(10), 1055; https://doi.org/10.3390/insects16101055 - 16 Oct 2025

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Abstract

The sycamore lace bug Corythucha ciliata (Hemiptera: Tingidae), an invasive North American forest pest, owes its strong dispersal and adaptability to biological characteristics and symbiotic microbes, but the underlying mechanisms have not been fully elucidated. This study examined its outdoor-collected (LYGO) and indoor-reared [...] Read more.

The sycamore lace bug Corythucha ciliata (Hemiptera: Tingidae), an invasive North American forest pest, owes its strong dispersal and adaptability to biological characteristics and symbiotic microbes, but the underlying mechanisms have not been fully elucidated. This study examined its outdoor-collected (LYGO) and indoor-reared (LYGI) populations using morphological observation, biological parameter assessment, and 16S rRNA sequencing. Key findings include: (1) Nymphs develop through five instars, with body size increasing significantly across stages; growth accelerated during 4th and 5th instars, reflecting a pattern of “low-instar accumulation and high-instar acceleration”. (2) Adult survival differed by sex, with females outliving males after 30 days; nymphs develop in 14.81 days, and each adult pair produced an average of 17 eggs, demonstrating a concentrated reproductive strategy; (3) Both populations shared dominant bacterial taxa (including the phyla Bacteroidota and Proteobacteria and the genus Cardinium) but diverged in non-dominant taxa; core microbial functions were conserved, while specific functions (e.g., glutathione S-transferase activity) varied. These results suggest a potential synergy between the insect’s biological characteristics (efficient development, concentrated reproduction) and the adaptive functions of its associated microbes in enhancing its invasiveness. The study supplements its basic biological data and offers a new view of its ecological adaptability. Full article

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

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13 pages, 2486 KB

Open AccessArticle

RNAi of vATPasea Affects Survival and Larval-Pupal Development in Plutella xylostella

by Xuetao Yu, Jinhua Luo, Lin Lu, Li Zhu, Siyuan Wang, Kang Yang, Xia Wan, Yuhua Wu, Boboev Akmal, Gang Wu, Xiaohong Yan and Chenhui Shen

Insects 2025, 16(10), 1054; https://doi.org/10.3390/insects16101054 - 16 Oct 2025

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Abstract

The diamondback moth, Plutella xylostella, is a major pest of brassica vegetables and oilseed crops, posing a serious threat to China’s grain and oil production. RNA interference (RNAi) has been developed as an efficient strategy to control pests. In this study, the [...] Read more.

The diamondback moth, Plutella xylostella, is a major pest of brassica vegetables and oilseed crops, posing a serious threat to China’s grain and oil production. RNA interference (RNAi) has been developed as an efficient strategy to control pests. In this study, the effects of RNAi on P. xylostella were evaluated by injecting two doses of synthesized dsPxvATPasea. The transcripts of PxvATPasea were widely transcribed during different developmental stages from egg to adult. They were abundantly expressed in the hindgut and Malpighian tubules, compared with other tissue types. Introduction of 800 ng dsPxvATPasea in the fourth-instar larvae greatly reduced corresponding mRNA levels by 3.1 and 1.4 times on day 2 and 3, respectively, causing 66.6% mortality and 33.4% treated larvae pupated. Silencing PxvATPasea by injecting 1200 ng dsRNA significantly decreased the expression level by 5.0 and 2.0 times on the second and third day, leading to 79.2% larval lethality and 20.8% depleted larvae pupated. Moreover, introducing 800 ng or 1200 ng dsPxvATPasea finally reduced larval fresh weight by 22.1% and 28.8%, respectively. The results indicated that the silencing efficiency of PxvATPasea worked in a dose-dependent way. Consequently, PxvATPasea is a potential molecular target gene. Our findings will facilitate the application of RNAi technology to manage P. xylostella. Full article

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

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13 pages, 2986 KB

Open AccessArticle

Diversity, Distribution, and Host Blood Meals of Black Flies (Diptera: Simuliidae) in Laos

by San Namtaku, Wannachai Wannasingha, Waraporn Jumpato, Khamla Inkhavilay, Bhuvadol Gomontean, Komgrit Wongpakam, Chavanut Jaroenchaiwattanachote, Isara Thanee, Ronnalit Mintara, Peter H. Adler and Pairot Pramual

Insects 2025, 16(10), 1053; https://doi.org/10.3390/insects16101053 - 16 Oct 2025

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Abstract

Adult black flies were collected from diverse habitats in five provinces of Laos. In total, 4659 adults (4570 females and 89 males) were collected. Morphological identification, supplemented with the mitochondrial cytochrome c oxidase I gene, revealed 12 species. The most abundant taxa were [...] Read more.

Adult black flies were collected from diverse habitats in five provinces of Laos. In total, 4659 adults (4570 females and 89 males) were collected. Morphological identification, supplemented with the mitochondrial cytochrome c oxidase I gene, revealed 12 species. The most abundant taxa were Simulium khelangense/S. chumpornense and S. asakoae/S. myanmarense with 58% (2628 of 4476) and 38% (1720 of 4476) of the total specimens, respectively. Simulium asakoae/S. myanmarense was the most geographically widespread taxon (65% of sites) from 174 to 1219 m above sea level. The remaining species were far less abundant (<2%) and found in only one or a few locations. Molecular identifications of vertebrate blood meals indicated that most hosts (57 of 66) were chickens. Five taxa, S. asakoae, S. khelangense, S. myanmarense, S. aureohirtum, and S. striatum group, fed on chickens, representing the first hosts records for the latter three taxa. Simulium daoense fed on water buffalo, marking the first record of this species in Laos and the first report of its blood hosts. The abundance and frequent use of domestic chickens as hosts suggests that S. khelangense and S. asakoae could be significant pests and might serve as vectors of avian blood parasites in Laos. Full article

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

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19 pages, 2978 KB

Open AccessArticle

Transgenerational Cold Acclimation and Contribution of Gut Bacteria in Spodoptera frugiperda

by Yu Song, Guo-Yun Yu, Wei Gao, Yu-Tong Mai, Jin Xu, Wen Fu and Zhi-Xiao Zhang

Insects 2025, 16(10), 1052; https://doi.org/10.3390/insects16101052 - 16 Oct 2025

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Abstract

The study of cold stress and adaptability can provide a theoretical basis for predicting and controlling pests. Temperature shapes gut microbiota composition, and gut microbiota may affect insect temperature tolerance. However, the underlying mechanisms and bacteria species involved in insect temperature tolerance through [...] Read more.

The study of cold stress and adaptability can provide a theoretical basis for predicting and controlling pests. Temperature shapes gut microbiota composition, and gut microbiota may affect insect temperature tolerance. However, the underlying mechanisms and bacteria species involved in insect temperature tolerance through gut microbiota are still poorly known. In this study, using a multigenerational cold-acclimation design and 16S rDNA sequencing, we investigated the possible pattern of cold acclimation and the contribution of gut bacteria in Spodoptera frugiperda. Results show that during cold acclimation, larval mortality decreased and pupation rate increased with the increase of treating generations, exhibiting some sort of cold adaptation. Cold tolerance tests showed that cold-acclimated adults exhibited significantly higher survival rates under extreme cold stress than those of controls. Cold acclimation also leads to the cost of reproductive fitness, indicating some trade-offs between survival and reproduction. Antibiotic treatment significantly decreased fitness and cold tolerance not only in the un-acclimated lines but also in cold-acclimated lines. Biodiversity studies through 16S RNA sequencing suggested that antibiotic ingestion disrupted the homeostasis of gut microbes. Differential analysis at the genus and species levels further showed that there were nine genera and eight species that had remarkably higher abundance in cold-acclimated lines compared with controls. References-based functional annotation revealed that most of these bacteria may play essential roles in the cold adaptation of hosts. These results provide valuable insights into the contribution of microbiota to insect fitness and will be valuable for guiding the future development of sustainable pest management approaches. Full article

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

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15 pages, 3028 KB

Open AccessArticle

Stage-Specific Toxicity of Novaluron to Second-Instar Spodoptera frugiperda and Plutella xylostella and Associated Enzyme Responses

by Qing Feng, Jian Yang, Weikang Huang, Jingjing Jia, Jialing Wang, Fei Pan and Xuncong Ji

Insects 2025, 16(10), 1051; https://doi.org/10.3390/insects16101051 - 15 Oct 2025

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Abstract

To provide a scientific basis for pest control, this study evaluated the insecticidal activity of novaluron against the fall armyworm (Spodoptera frugiperda) and diamondback moth (Plutella xylostella). The leaf-dip method determined the toxicity of novaluron to second-instar larvae, while [...] Read more.

To provide a scientific basis for pest control, this study evaluated the insecticidal activity of novaluron against the fall armyworm (Spodoptera frugiperda) and diamondback moth (Plutella xylostella). The leaf-dip method determined the toxicity of novaluron to second-instar larvae, while corn leaves and cabbage treated with sublethal (LC₁₀) and median lethal concentrations (LC₅₀) of novaluron were used to feed the larvae. Enzyme-linked immunosorbent assays (ELISA) measured the activities of detoxifying enzymes [carboxylesterase (CarE), cytochrome P450 (P450), glutathione S-transferase (GST), and acetylcholinesterase (AChE)] and ecdysteroid (Ecd) levels in the pests after 24 and 48 h of treatment. Results indicated that after 24 h, AChE was involved in diamondback moth metabolism and CarE activity was inhibited. After 48 h, P450 and GST participated in fall armyworm detoxification, whereas P450 and GST were active in diamondback moth detoxification, with other enzyme activities normalizing. Novaluron also altered Ecd levels in both pests. These results demonstrate differing detoxification mechanisms in fall armyworm and diamondback moth, likely due to their unique physiological and ecological traits, and support the potential use of novaluron in pest management strategies. Full article

(This article belongs to the Special Issue Insecticide Resistance and Toxicology: Challenges in Pest Management and Basic Research—2nd Edition)

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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

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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

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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

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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

Viewed by 731

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

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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

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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

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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

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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

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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

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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

Viewed by 467

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

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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

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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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