Insects

24 pages, 5200 KB

Open AccessArticle

A Taxonomic Revision of the East Mediterranean Species of the Crematogaster scutellaris Complex (Hymenoptera: Formicidae)

by Sándor Csősz, Laura El-Ghor and Herbert C. Wagner

Insects 2026, 17(6), 658; https://doi.org/10.3390/insects17060658 - 22 Jun 2026

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Abstract

The taxonomy of the East Mediterranean species of the Crematogaster scutellaris complex, Crematogaster schmidti (Mayr, 1853) and C. ionia Forel, 1911 sensu lato, has not yet been investigated via modern approaches like morphometric analyses. We collected morphometric data of 201 workers from 68 [...] Read more.

The taxonomy of the East Mediterranean species of the Crematogaster scutellaris complex, Crematogaster schmidti (Mayr, 1853) and C. ionia Forel, 1911 sensu lato, has not yet been investigated via modern approaches like morphometric analyses. We collected morphometric data of 201 workers from 68 nests of Crematogaster schmidti and C. ionia s. l. from Slovenia, Croatia, Montenegro, North Macedonia, the Greek mainland, Crete, Bulgaria, Samos, Karpathos, Rhodes, Turkish Thrace, and Anatolia. Nest-centroid clustering suggested four distinct entities with different geographic distributions: C. schmidti from Slovenia southwards to Greece and Turkish Thrace, and three species which have been so far summarized under C. ionia: one from the Greek mainland and North Macedonia, one from Crete, and one from Samos, Karpathos, Rhodes, and Anatolia. We describe two new species: the Cretan entity as Crematogaster ariadnae sp. n. and the Balkan mainland entity as Crematogaster graeca sp. n. A key and (re)descriptions for the East Mediterranean members of the Crematogaster scutellaris complex are provided. The four species show different geographic distribution patterns, do not occur together at the same localities, and most likely speciated through long-term geographic isolation. Full article

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

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21 pages, 16570 KB

Open AccessArticle

Structural Characteristics for the Interaction of 1-Benzyl-2-Methylbenzimidazoles as Insect Growth Regulators and Juvenile Hormone Binding Protein

by Udawaththa Kankanamge Don Sahan Suganda Gunasekara, Konatsu Inoue, Zui Fujimoto, Shuhei Henmi, Wataru Tsuchiya, Rintaro Suzuki, Keisuke Kutsuwada, Izumi Ikeda, Toshimasa Yamazaki and Takahiro Shiotsuki

Insects 2026, 17(6), 657; https://doi.org/10.3390/insects17060657 - 22 Jun 2026

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Abstract

The authors previously reported that 2-methylbenzimidazole derivatives (MBIs) exhibit insect growth-regulating activity against the silkworm, Bombyx mori. However, despite their unique effects on juvenile hormone (JH)-related endocrine pathways, the precise mode of action of MBIs remained unclear. In the present study, the [...] Read more.

The authors previously reported that 2-methylbenzimidazole derivatives (MBIs) exhibit insect growth-regulating activity against the silkworm, Bombyx mori. However, despite their unique effects on juvenile hormone (JH)-related endocrine pathways, the precise mode of action of MBIs remained unclear. In the present study, the interactions between MBIs and the lepidopteran hemolymph JH-binding protein (JHBP), a key regulator of JH transport and activity, were investigated using multiple approaches, including in vitro binding affinity assays, X-ray crystallography, and molecular docking simulations. A series of MBIs bearing a 1-(4-alkoxybenzyl) group, which exhibited potent insect growth-regulating activity, showed high binding affinity and structural compatibility with the JH-binding pocket of JHBP. In contrast, 1-(4-alkylbenzyl) MBIs, which displayed weak or negligible insect growth-regulating activity, exhibited low affinity for JHBP. These findings suggest that the insect growth-regulating activity of MBIs is mediated through inhibition of JHBP function, likely by disrupting the precise regulation of JH concentration in the hemolymph during larval development and pupal metamorphosis. Full article

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

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19 pages, 4132 KB

Open AccessArticle

Structure of Epigeic and Arboreal Ant Communities in Forest Fragments Within Agricultural Landscapes of the Brazilian Cerrado

by Helivelton H. M. Araújo, Vagner S. Vale, Flávio G. Jesus, Ednaldo C. Rocha, Carlos de M. Silva-Neto, André C. S. Almeida, Matheus C. Heinzelmann and Márcio S. Araújo

Insects 2026, 17(6), 656; https://doi.org/10.3390/insects17060656 - 22 Jun 2026

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Abstract

A large portion of the Brazilian Cerrado vegetation currently exists as small, disturbed, and isolated fragments. Evaluating the degree of anthropogenic disturbance in certain environments has been successfully achieved using bioindicator insects, particularly ants. This study aims to characterize the epigeic and arboreal [...] Read more.

A large portion of the Brazilian Cerrado vegetation currently exists as small, disturbed, and isolated fragments. Evaluating the degree of anthropogenic disturbance in certain environments has been successfully achieved using bioindicator insects, particularly ants. This study aims to characterize the epigeic and arboreal ant communities in Cerrado fragments in the southeastern region of Goiás, bordered by agricultural crops, during both the dry and wet seasons, and to correlate these ant communities with the structural characteristics of the forest fragments. Morphospecies richness and ant community structure across the different environments were compared, and bioindicator species were proposed using the Indicator Value (IndVal) method. The ant community structure under the evaluated conditions was significantly altered, indicating effects that extend beyond fragment-specific variables and are associated with the surrounding agricultural landscape. The IndVal analysis suggested two environmental quality indicator species for the ground stratum: Pheidole cf. radoszkowskii and Crematogaster stollii. However, it did not point to any significant indicator species for the arboreal stratum. Ants mediate various functional roles and shifts in the structure of local communities, reinforcing the importance of these insects as bioindicators of environmental quality. Full article

(This article belongs to the Special Issue Hymenoptera in Agroecosystems: Functions, Risks, and Management)

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30 pages, 7112 KB

Open AccessReview

Insects as an Alternative Protein Source: A Sustainable Approach to Future Food Security

by Mohd Suhail Banday, Ambashree Dubey, Neha Thakur, Saima Banday, Jyoti Jawla, Jameel Ahmad, Esteban Pérez-García, Ariana Saraiva, Hmidan A. Alturki and António Raposo

Insects 2026, 17(6), 655; https://doi.org/10.3390/insects17060655 - 22 Jun 2026

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Abstract

Edible insects are increasingly recognized as a viable alternative protein source, offering a potentially sustainable approach to addressing global food security challenges. This narrative review critically examines the nutritional composition, environmental advantages, techno-functional attributes, and potential applications of insect-based proteins within human food [...] Read more.

Edible insects are increasingly recognized as a viable alternative protein source, offering a potentially sustainable approach to addressing global food security challenges. This narrative review critically examines the nutritional composition, environmental advantages, techno-functional attributes, and potential applications of insect-based proteins within human food systems. Edible insects are characterized by high protein content, favourable essential amino acid profiles, and appreciable levels of key micronutrients, rendering them nutritionally comparable to conventional livestock-derived proteins. Moreover, insect production systems generally require substantially lower inputs of land, water, and feed, resulting in comparatively lower greenhouse gas emissions and reduced overall environmental burden. Despite these advantages, broader adoption remains constrained by challenges related to regulatory heterogeneity, food safety concerns, and limited consumer acceptance. Overall, the available evidence suggests that edible insects can function as a nutritionally adequate and environmentally sustainable complementary protein source; however, significant variability in nutrient composition, limitations in standardized safety assessment, and socio-cultural barriers currently restrict their large-scale integration into mainstream food systems. In addition, inconsistencies in analytical methodologies and reliance on in vitro data further complicate cross-study comparisons and translational relevance. Future research should focus on standardization of rearing and processing conditions, harmonization of evaluation frameworks (e.g., protein quality indices), comprehensive safety assessments, and well-designed clinical studies to validate nutritional and functional benefits, alongside the development of effective strategies to improve consumer acceptance and support regulatory alignment across regions. Full article

(This article belongs to the Special Issue Insects as Food: Advances in Edible Insect Research and Applications)

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16 pages, 3214 KB

Open AccessArticle

Carpet Beetle Species (Coleoptera: Dermestidae) in Austrian Heritage Interiors and Their European Distributions

by Peter Brimblecombe, Graham Holloway and Pascal Querner

Insects 2026, 17(6), 654; https://doi.org/10.3390/insects17060654 - 22 Jun 2026

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Abstract

Museum collections are at risk from insects. A changing climate or increased amounts of imported materials, exhibition loans and international travel, can increase exotic species. Heritage properties are often monitored for pests, so we used trapping data from 31 Austrian museums, libraries and [...] Read more.

Museum collections are at risk from insects. A changing climate or increased amounts of imported materials, exhibition loans and international travel, can increase exotic species. Heritage properties are often monitored for pests, so we used trapping data from 31 Austrian museums, libraries and storerooms. The carpet beetles Anthrenus spp. and Attagenus spp. studied here, showed that the catch of these two species in buildings was correlated. Unheated libraries show high catch rates for Anthrenus spp., Attagenus spp. seemed more often caught in heated/urban museums. Anthrenus verbasci, Anthrenus olgae and Anthrenus museorum account for almost 98% of our catch. Anthrenus verbasci and Anthrenus olgae are commonly found occurring together suggesting they form a core ecological pair, found in most buildings. Rarer Anthrenus fuscus appears typically at locations lacking winter heating. Attagenus smirnovi and Attagenus unicolor accounted for 95% of this genus in the buildings. There are notable differences in the types of carpet beetle across European heritage environments. Anthrenus olgae, often trapped in Austria, is uncommon elsewhere, while Anthrenus sarnicus, fairly common in the UK, is rare elsewhere. Not enough is known about the range of heritage insects across Europe, which is increasingly relevant to management under a changing climate. Full article

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

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14 pages, 1278 KB

Open AccessArticle

Can Trapping Abundance Data Be Used to Identify Persistent Target Areas for Culicoides Biting Midge Control Efforts?

by Aaron M. Lloyd, Daniel L. Kline, Karen E. McKenzie and Daniel A. Hahn

Insects 2026, 17(6), 653; https://doi.org/10.3390/insects17060653 - 20 Jun 2026

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Abstract

Florida mosquito control districts are increasingly confronted with severe Culicoides biting midge problems in coastal areas. Yet, there is no clear guidance for integrating Culicoides management into mosquito-focused operations. This study describes population abundance and distribution trends for the biting midge Culicoides furens [...] Read more.

Florida mosquito control districts are increasingly confronted with severe Culicoides biting midge problems in coastal areas. Yet, there is no clear guidance for integrating Culicoides management into mosquito-focused operations. This study describes population abundance and distribution trends for the biting midge Culicoides furens on a residential island in Cedar Key, Florida. We use multi-year adult trapping data to help develop strategies that may be used by mosquito control districts to target C. furens populations where they are nuisance pests. Trap data from 2005 and 2007 identified seasonal peaks, high spatial heterogeneity, and substantial year-to-year variation, with an 88.3% reduction in trap captures between 2005 and 2007. These findings provide a foundation for integrated Culicoides management strategies where legal mandates, emerging pathogen risks, and taxpayer-driven nuisance complaints may justify expanded Culicoides control activities by Florida’s Mosquito Control Districts. Full article

(This article belongs to the Special Issue Advances in Applied Science Technologies for Surveillance and Management of Arthropods of Public Health Importance)

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21 pages, 3911 KB

Open AccessArticle

Time-Resolved Whole-Transcriptome Analysis Suggests Candidate Non-Coding RNA Regulatory Networks Associated with PBAN-Induced Pheromone Biosynthesis in Ostrinia furnacalis

by Hanbo Zhao, Lei Liu, Bin Yang and Guirong Wang

Insects 2026, 17(6), 652; https://doi.org/10.3390/insects17060652 - 20 Jun 2026

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Abstract

The biosynthesis of sex pheromones in lepidopteran pheromone glands is tightly regulated by pheromone biosynthesis-activating neuropeptide (PBAN) signaling; yet the contribution of non-coding RNA-mediated post-transcriptional regulation remains largely unclear. This study aimed to characterize temporal transcriptomic changes, candidate non-coding RNA-mediated regulatory associations, and [...] Read more.

The biosynthesis of sex pheromones in lepidopteran pheromone glands is tightly regulated by pheromone biosynthesis-activating neuropeptide (PBAN) signaling; yet the contribution of non-coding RNA-mediated post-transcriptional regulation remains largely unclear. This study aimed to characterize temporal transcriptomic changes, candidate non-coding RNA-mediated regulatory associations, and temporal molecular dynamics underlying transcriptional remodeling after PBAN treatment in Ostrinia furnacalis. First, we performed comprehensive whole-transcriptome sequencing (WTS) on 18 biologically independent samples collected at six time points (0, 20, 40, 60, 90, and 120 min) after PBAN injection. Then, we systematically identified and quantified the dynamic expression patterns of differentially expressed (DE) mRNAs, miRNAs, lncRNAs, and circRNAs in response to PBAN stimulation. By integratively analyzing these multidimensional omics datasets and inferring sequence-based interaction relationships, we inferred a dynamic candidate competing endogenous RNA (ceRNA) like regulatory network. The candidate ceRNA network anchored four core node genes: the PBAN receptor (PBANR), the rate-limiting enzyme acetyl-CoA carboxylase (ACC), and the terminal biosynthetic enzymes desaturase (DES) and fatty acyl-CoA reductase (FAR). The qRT-PCR results further support the temporal expression pattern of key genes during the PBAN response, suggesting that this network can provide a valuable resource for further functional studies. Full article

(This article belongs to the Special Issue Insect Transcriptomics)

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13 pages, 2362 KB

Open AccessArticle

The Effects of Thiacloprid on Essential Components of Navigation and Pollination in Bumble Bees: A Laboratory Approach

by Inga Fuchs and Randolf Menzel

Insects 2026, 17(6), 651; https://doi.org/10.3390/insects17060651 - 20 Jun 2026

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Abstract

We developed a laboratory-based setup to perform behavioral tests of the effect of the neonicotinoid insecticide Thiacloprid in the CALYPSO^® formulation on bumblebees. This setup simulates essential components of navigation and pollination under natural conditions. The behavioral components are exploration, exploratory learning, [...] Read more.

We developed a laboratory-based setup to perform behavioral tests of the effect of the neonicotinoid insecticide Thiacloprid in the CALYPSO^® formulation on bumblebees. This setup simulates essential components of navigation and pollination under natural conditions. The behavioral components are exploration, exploratory learning, learning of a rewarded local cue in the context of a specific panorama, and retrieving the memory for this association. The walking bumblebees navigated under their own motivation between a fully functional colony and a training/test arena. They explored the arena and learned the association of a rewarded local cue in the context of a panorama. The rule of association was that the local cue was bound to a particular part of the panorama irrespective of where it appeared in its spatial relation to the entrance gate through which the animal came from the colony. Extinction tests were performed for two conditions, match and mismatch. The match condition resembled the training condition. In the mismatch condition the local cue appeared in a different part of the panorama. Solving this task requires the learning and remembering of a rule under variable conditions, mimicking the cognitive requirements faced by bumblebees under natural conditions. The control animals solved this task, whereas animals treated with Thiacloprid 400 ng CALYPSO^® diluted in 4 µL per animal were significantly compromised, as shown by several parameters of the walking trajectories under the match and mismatch conditions. No dose–response functions were established, but a volume of 800 ng CALYPSO^® diluted in 8 µL per animal did not show any significant differences from a volume of 4 µL CALYPSO^®. The setup and the experimental paradigm are suitable for routine quantitative tests on the effects of insecticides on the cognitive faculties of insects during navigation and pollination. Full article

(This article belongs to the Special Issue Experimental and Field Approaches Using Pollinating Insects as Model Systems)

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14 pages, 4328 KB

Open AccessArticle

Efficacy of Mating Disruption Treatments Against Spongy Moth (Lymantria dispar dispar) Applied Using Unmanned Aerial Vehicles

by Ksenia S. Onufrieva, Andrea D. Hickman and Tom W. Coleman

Insects 2026, 17(6), 650; https://doi.org/10.3390/insects17060650 - 20 Jun 2026

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Abstract

Unmanned aerial vehicles (UAVs) are increasingly used in precision pest management, yet their performance in operational forest settings remains underexplored. We evaluated the efficacy of SPLAT^® SM-O mating disruptant applied using a UAV at a dosage of 14.8 for control of the [...] Read more.

Unmanned aerial vehicles (UAVs) are increasingly used in precision pest management, yet their performance in operational forest settings remains underexplored. We evaluated the efficacy of SPLAT^® SM-O mating disruptant applied using a UAV at a dosage of 14.8 for control of the spongy moth, Lymantria dispar dispar L. (Lepidoptera: Erebidae). One treatment plot received 11.4 g AI/ha because of a calibration deviation during application. Both treatments reduced trap catches by >90% for 10 weeks following the application, meeting the efficacy requirement set by the USDA’s National Slow the Spread (STS) Program. One year after the application, trap catches continued to be reduced by 28% and 67% in plots treated with 14.8 and 11.4 g AI/ha, respectively. These levels of trap catch reduction in the year of treatment and one year after the treatment application are comparable to those reported following fixed-wing aerial treatments. These results indicate that UAV-applied SPLAT^® SM-O meets STS requirements for operational use and is suitable for integration into the program for treating small or isolated blocks. These findings also have broader implications for the use of unmanned aerial vehicles to deploy SPLAT^® formulations in forest pest management programs. Full article

(This article belongs to the Special Issue Integrated Pest Management in Agricultural Crops and Forest Ecosystems—2nd Edition)

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13 pages, 19998 KB

Open AccessArticle

Two New Species of the Genus Meleonoma (Lepidoptera, Autostichidae) from China, Revealed by Morphological and Phylogenetic Evidence

by Xiaoju Zhu, Xiuxiu Zhu and Shuxia Wang

Insects 2026, 17(6), 649; https://doi.org/10.3390/insects17060649 - 19 Jun 2026

Viewed by 367

Abstract

Meleonoma belonging to the subfamily Periacminae is one of the most species-rich genus in the family Autostichidae. In this study, we described two new species: M. latizona sp. nov. and M. serrulata sp. nov. A phylogenetic analysis of these and closely related species [...] Read more.

Meleonoma belonging to the subfamily Periacminae is one of the most species-rich genus in the family Autostichidae. In this study, we described two new species: M. latizona sp. nov. and M. serrulata sp. nov. A phylogenetic analysis of these and closely related species was conducted based on mitochondrial genes to achieve a better understanding of their taxonomic status of the two new species. Full article

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

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21 pages, 8004 KB

Open AccessArticle

Comparative Transcriptomic Analysis of Detoxification Enzyme Gene Families in Parent and Offspring Riptortus pedestris After Sublethal Thiamethoxam Treatment

by Sizhu Zhao, Zijie Wang, Simeng Chen, Ruirui Li, Zhengxiao Du, Xing Huang, Haibin Yuan, Shusen Shi, Yuxin Zhou and Yu Gao

Insects 2026, 17(6), 648; https://doi.org/10.3390/insects17060648 - 19 Jun 2026

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Abstract

Thiamethoxam is the main neonicotinoid insecticide used for controlling Riptortus pedestris (Fabricius) (Hemiptera: Alydidae). However, sublethal concentration stress may induce intergenerational transcriptional memory, leading to transcriptional patterns that may contribute to the intergenerational accumulation of metabolic tolerance, and evaluating only the toxicity of [...] Read more.

Thiamethoxam is the main neonicotinoid insecticide used for controlling Riptortus pedestris (Fabricius) (Hemiptera: Alydidae). However, sublethal concentration stress may induce intergenerational transcriptional memory, leading to transcriptional patterns that may contribute to the intergenerational accumulation of metabolic tolerance, and evaluating only the toxicity of the current generation would underestimate the long-term risk. Therefore, this study investigated the effect of parental exposure on the expression of detoxification enzyme genes in offspring. Using transcriptome sequencing, we systematically identified three detoxification enzyme gene families (cytochrome P450 monooxygenases (CYPs), carboxylesterases (CCEs), and glutathione S-transferases (GSTs)) in R. pedestris and compared their differential expression patterns between the parental and filial generations after thiamethoxam treatment at three sublethal concentrations (LC₁₀, LC₃₀, and LC₅₀). In the parental generation, a Theta family GST was consistently upregulated, while in the filial generation, detoxification genes were predominantly downregulated, and the genes upregulated in the parents were not also upregulated in the offspring. Comparisons of parents and offspring at the same concentration revealed that the medium concentration induced the highest number of intergenerationally upregulated genes, exhibiting a non-linear response pattern. These results indicate that parental exposure to sublethal thiamethoxam leaves an intergenerational transcriptional imprint in the offspring, and the transmission pattern involves transcriptional reprogramming rather than simple replication of the parental response, the mechanism of which remains to be determined. This study provides transcriptomic evidence for understanding the metabolic adaptation and intergenerational resistance evolution of R. pedestris to thiamethoxam, offering important reference value for field resistance monitoring and rational insecticide application. Full article

(This article belongs to the Special Issue Advances in the Effects of Insecticides on Pests)

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17 pages, 6760 KB

Open AccessArticle

Diversity and Host Blood Meal Analysis of Culicoides (Diptera: Ceratopogonidae) from Laos

by Ronnalit Mintara, Wannachai Wannasingha, Chavanut Jaroenchaiwattanachote, Waraporn Jumpato, San Namtaku, Khamla Inkhavilay, Isara Thanee and Pairot Pramual

Insects 2026, 17(6), 647; https://doi.org/10.3390/insects17060647 - 18 Jun 2026

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Abstract

Many biting midge species of the genus Culicoides Latreille are significant pests and vectors that transmit diverse parasites to humans and other animals. However, knowledge of these hematophagous insects in Laos remains limited, with the most recent information reported more than four decades [...] Read more.

Many biting midge species of the genus Culicoides Latreille are significant pests and vectors that transmit diverse parasites to humans and other animals. However, knowledge of these hematophagous insects in Laos remains limited, with the most recent information reported more than four decades ago. In this study, we investigated Culicoides species diversity, DNA barcoding and host blood sources using specimens collected across seven provinces in northern, central, and southern Laos. A total of 4592 specimens were collected, comprising 3095 females and 1497 males. Morphological identification, complemented by DNA barcode analysis, revealed 26 species (24 named and 2 unnamed), including five (three named and two unnamed) new country records. Culicoides peregrinus was the most abundant species, representing 25.7% (1179 individuals), followed by C. oxystoma at 23.8% (1093 individuals), and C. arakawae/C. mahasarakhamense, which together comprised 18.5% (849 individuals) of the total specimens. DNA barcode analysis demonstrated that this genetic marker is effective for species identification of Culicoides in Laos. Of the 115 COI sequences, 103 (89.6%) were successfully matched with conspecifics in the BOLD database. Cryptic genetic diversity was detected in three species, C. clavipalpis, C. palpifer, and C. huffi, with two, two, and three divergent lineages, respectively. Host blood meal analysis revealed that chickens and domestic water buffalo were the most common blood sources for the investigated Culicoides species. These findings provide important baseline information for future studies on the pest and vectorial roles of Culicoides in Laos. Full article

(This article belongs to the Special Issue DNA Barcoding for Insect Biodiversity and Pest Monitoring)

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17 pages, 1628 KB

Open AccessReview

Insight into the Prospects of RNA Interference for Honey Bee Pathogens and Parasite Control

by A-Tai Truong, Mi-Sun Yoo, Khanh Linh Ha Tran, So Youn Youn, Hyang-Sim Lee and Yun Sang Cho

Insects 2026, 17(6), 646; https://doi.org/10.3390/insects17060646 - 18 Jun 2026

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Abstract

Honey bee populations face significant threats from viral pathogens, Nosema ceranae, Varroa destructor, and the small hive beetle (Aethina tumida), all of which contribute to colony losses worldwide. RNA interference (RNAi) has emerged as a promising molecular tool for [...] Read more.

Honey bee populations face significant threats from viral pathogens, Nosema ceranae, Varroa destructor, and the small hive beetle (Aethina tumida), all of which contribute to colony losses worldwide. RNA interference (RNAi) has emerged as a promising molecular tool for controlling these pathogens and pests through sequence-specific gene silencing. This review summarizes current advances in RNAi applications against major honey bee diseases and parasites, including antiviral strategies, suppression of Nosema development, interference with Varroa reproduction, and RNAi-based control of small hive beetles. Particular attention is given to recent developments in delivery technologies, including oral administration, nanoparticle-assisted formulations, and symbiont-mediated RNAi systems. The opportunities, limitations, and future challenges associated with large-scale implementation, environmental safety, regulatory approval, and field deployment are also discussed. Collectively, these advances highlight the potential of RNAi as a valuable component of sustainable honey bee health management and integrated pest management programs. Full article

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

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16 pages, 3273 KB

Open AccessArticle

Selectively Targeting of Gardeners and Symbiotic Fungus in Leaf-Cutting Ant Colonies Using Essential Oils

by Andressa Graebin, Patrícia F. Pinheiro, Karina D. Amaral, Vinicius F. Santos, Tarciza F. Nascimento, Marcela V. de S. Vilela, Yenara K. M. Silva, Thais D. Marcelino and Raul Narciso C. Guedes

Insects 2026, 17(6), 645; https://doi.org/10.3390/insects17060645 - 18 Jun 2026

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Abstract

Social insect pests such as leaf-cutting ants challenge conventional pest management because effective control must disrupt colony-level organization rather than target individual insects. Colony persistence depends on the mutualistic association between gardener workers and their cultivated fungus, Leucoagaricus gongylophorus. Compounds that selectively [...] Read more.

Social insect pests such as leaf-cutting ants challenge conventional pest management because effective control must disrupt colony-level organization rather than target individual insects. Colony persistence depends on the mutualistic association between gardener workers and their cultivated fungus, Leucoagaricus gongylophorus. Compounds that selectively impair these components while preserving forager-mediated bait transport may therefore offer strategic advantages. We evaluated the essential oils of weeping willow (Salix babylonica), Surinam cherry (Eugenia uniflora), weeping bottlebrush (Melaleuca viminalis), ginger (Zingiber officinale), and black pepper (Piper nigrum) against two leaf-cutting ant species, Atta sexdens and Acromyrmex subterraneus, after characterizing their chemical composition by GC–MS. The oils displayed distinct terpenoid profiles: bottlebrush oil, for instance, was dominated by 1,8-cineole and α-pinene, while ginger oil was rich in camphene and β-phellandrene. Forager and gardener workers were tested separately, along with their symbiotic fungus. Responses were generally concentration-dependent, although effects varied among oils and biological targets. Ginger oil exhibited strong fungicidal activity, but only at the highest concentration tested (100 mg mL⁻¹). Bottlebrush oil showed marked toxicity to A. sexdens gardeners at concentrations as low as 0.10 mg mL⁻¹, while effects on foragers were comparatively low. The remaining oils produced limited or inconsistent responses. These findings indicate that caste-selective toxicity and fungal suppression are achievable but not widespread among essential oils. Bottlebrush oil emerges as a promising candidate for further investigation, particularly regarding its constituent compounds and potential synergistic interactions for toxic bait development. Full article

(This article belongs to the Special Issue An Eco-Friendly Approach for Pest Management)

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16 pages, 5497 KB

Open AccessArticle

Analysis of Midgut Microbial Diversity and Hemolymph Metabolomics in Silkworm (Bombyx mori L.) Varieties with Different Artificial Diet Feeding Habits

by Shengxiang Zhang, Yating Liu, Wenhui Song, Chunjiu Ren, Junwen Ai, Bing Han, Huiju Gao and Bing Wang

Insects 2026, 17(6), 644; https://doi.org/10.3390/insects17060644 - 18 Jun 2026

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Abstract

As important silkworm varieties reared on artificial diet, Youshi No. 1 (YS) and Guangshi No. 1 (GS) showed remarkable differences in physiological characteristics. GS had significantly better performance than YS in body weight, cocooning ability, food intake, feed utilization efficiency, and digestive enzyme [...] Read more.

As important silkworm varieties reared on artificial diet, Youshi No. 1 (YS) and Guangshi No. 1 (GS) showed remarkable differences in physiological characteristics. GS had significantly better performance than YS in body weight, cocooning ability, food intake, feed utilization efficiency, and digestive enzyme activities. We further performed metabolomics and 16S rRNA high-throughput sequencing to analyze their metabolic profiles and midgut microbiota. More than 40 differential metabolites were screened out, and four metabolic pathways related to feeding divergence were determined via KEGG enrichment, among which L-valine was enriched in multiple pathways. Significant structural differences were also observed in midgut microbiota, and Bacillus was positively correlated with pantothenic acid and valine metabolism. These correlational results disclosed that differential metabolites and gut microbiota might underlie the phenotypic variations between the two varieties. Integrated analysis combined with functional verification experiments demonstrated that supplementation of 1% L-valine or specific Bacillus strains in an artificial diet was associated with the improvement of the growth performance, cocoon quality, and feed utilization efficiency of the YS silkworm variety. Full article

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

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14 pages, 5124 KB

Open AccessArticle

Identification and Characterization of the Detoxification Genes from the Transcriptome of Plagiodera versicolora

by Xiao-Long Liu, Hai-Dong Sun, Yi-Wen Pei, Min Lu and Hai-Nan Zhang

Insects 2026, 17(6), 643; https://doi.org/10.3390/insects17060643 - 18 Jun 2026

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Abstract

Plagiodera versicolora (Coleoptera: Chrysomelidae), the willow leaf beetle, is a leaf-eating pest that generally occurs on salicaceous trees. However, there is a blank of identification and phylogenetic relationship of the detoxification genes in P. versicolora. Here, we identified four detoxification gene families [...] Read more.

Plagiodera versicolora (Coleoptera: Chrysomelidae), the willow leaf beetle, is a leaf-eating pest that generally occurs on salicaceous trees. However, there is a blank of identification and phylogenetic relationship of the detoxification genes in P. versicolora. Here, we identified four detoxification gene families (glutathione S-transferases: GSTs, UDP-glycosyltransferases: UGTs, cytochrome P450 monooxygenases: CYPs and carboxylesterases: COEs) from the adult antennal transcriptome data. In all, 146 candidate detoxification genes including 22 GSTs, 20 UGTs, 60 CYPs, and 44 COEs were identified. We used quantitative real-time PCR technology to explore the tissue expression patterns of 12 PvGSTs in P. versicolora. The results showed that 7 PvGSTs have significantly high expression in antennae, indicating these PvGSTs may play an important role in degrade and/or inactivate the sex pheromones and host volatiles. The identification and phylogenetics of the detoxification genes in P. versicolora extended the database in Coleoptera and contributed to the subsequent in-depth research for function about detoxification genes. Full article

(This article belongs to the Special Issue Insect Transcriptomics)

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22 pages, 4752 KB

Open AccessArticle

Integrated Morphological and Transcriptomic Analyses of Gene Regulatory Mechanisms in Different Intra-Puparial Developmental Stages of Phormia regina

by Jiani Yang, Ruonan Zhang, Rui Zhu, Lan Gao, Chenbin Wang, Zhiya Gu and Yu Wang

Insects 2026, 17(6), 642; https://doi.org/10.3390/insects17060642 - 17 Jun 2026

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Abstract

Phormia regina (Meigen, 1826) (Diptera: Calliphoridae), a necrophagous blow fly of significant forensic value, plays a crucial role in postmortem interval (PMI) estimation. The intra-puparial period of this species constitutes approximately half of its entire immature developmental duration. Therefore, precise aging of intra-puparial [...] Read more.

Phormia regina (Meigen, 1826) (Diptera: Calliphoridae), a necrophagous blow fly of significant forensic value, plays a crucial role in postmortem interval (PMI) estimation. The intra-puparial period of this species constitutes approximately half of its entire immature developmental duration. Therefore, precise aging of intra-puparial specimens is essential to improve the accuracy of PMI estimation. This study was performed at a constant 25 °C, examining intra-puparial morphology, histological sections, and body weight across different developmental stages. Additionally, full-length transcriptome profiling was conducted via a hybrid sequencing strategy combining PacBio single-molecule real-time (SMRT) sequencing and Illumina short-read next-generation sequencing (NGS). Morphological studies revealed the intra-puparial morphological characteristics, the reconstruction process of tissues and organs, and the continuous body weight loss during the intra-puparial period. Transcriptomic research identified a total of 425,349 full-length non-chimeric (FLNC) sequences. After redundancy removal, 84,852 transcript sequences were obtained, of which 46,325 transcripts were annotated. Using day-0 puparia (D0) as the control, differentially expressed gene (DEG) analysis was performed on samples from subsequent developmental stages (D1–D5), identifying 4242, 7964, 9509, 10,526, and 10,011 DEGs, respectively. Results from GO enrichment and KEGG pathway analyses provided reasonable explanations for the behavioral traits of different developmental stages. Eight candidate genes for intra-puparial development were screened, most of which were highly expressed at different time points during the intra-puparial period. Quantitative real-time PCR (qRT-PCR) results showed consistent gene expression trends with the RNA-seq data, confirming the reliability of the RNA-seq results. This study provides key morphological and molecular markers for P. regina in forensic PMI estimation. Full article

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

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15 pages, 3967 KB

Open AccessArticle

Behavioral and Electrophysiological Evidence for Repellency of Phytolacca americana (Pokeweed) Fruit Extract in Plutella xylostella

by Yang Liu, Yong-Hao Zhai, Chen-Han Sun, Jia-Yi Yin, Li-Xia Liu, Tian-Bo Ding, Chun-Hong Yang, Guy Smagghe and Yan Shi

Insects 2026, 17(6), 641; https://doi.org/10.3390/insects17060641 - 17 Jun 2026

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Abstract

Phytolacca americana L. (pokeweed) is an invasive alien plant in China that experiences little herbivore or disease pressure, suggesting the presence of effective chemical defenses. Although insecticidal activity of P. americana tissues has been reported, its potential repellent effects against the diamondback moth, [...] Read more.

Phytolacca americana L. (pokeweed) is an invasive alien plant in China that experiences little herbivore or disease pressure, suggesting the presence of effective chemical defenses. Although insecticidal activity of P. americana tissues has been reported, its potential repellent effects against the diamondback moth, Plutella xylostella (L.), remain unexplored. In this study, we further optimized distillation conditions to obtain fruit extract (FE) from P. americana. Subsequently, its chemical composition was analyzed. behavioral repellency, and antennal olfactory activity against P. xylostella adults. Gas chromatography-mass spectrometry (GC-MS) tentatively identified 11 compounds, accounting for 96–99% of the total distillate composition. The major constituents in the final distillate were palmitic acid ethyl ester (26.00%), 6,10,14-trimethyl-2-pentadecanone (25.75%), and ethyl oleate (14.19%). Behavioral assays using a Y-tube olfactometer demonstrated that the FE, as well as diethyl phthalate, palmitic acid ethyl ester, and ethyl oleate, exhibited strong repellent activity against adult P. xylostella, whereas 6,10,14-trimethyl-2-pentadecanone showed moderate repellency only at high concentrations (10 μg/μL). Electroantennogram (EAG) recordings revealed robust antennal responses to the three highly repellent compounds, with ethyl oleate eliciting the strongest response (0.58 mV at 100 μg/μL). Furthermore, Diethyl phthalate shows moderate repellency to P. xylostella. These results indicate that P. americana FE mediates repellency primarily through olfactory perception and that its major constituents contribute substantially to this effect. Overall, this study provides the first laboratory evidence that P. americana FE functions as an effective olfactory repellent against P. xylostella. The findings offer preliminary proof-of-concept for developing phytogenic repellents. Full article

(This article belongs to the Special Issue Lepidoptera: Behavior, Ecology, and Biology)

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15 pages, 3438 KB

Open AccessArticle

Leaf Age-Dependent Volatile Cues Influence Host Location and Oviposition Preference of Obolodiplosis robiniae on Robinia pseudoacacia

by Weihan Xu, Jiaqiang Zhao, Qike Wang, Zhashenjiacan Bao, Yuan Xu, Haiwei Wu and Juan Shi

Insects 2026, 17(6), 640; https://doi.org/10.3390/insects17060640 - 17 Jun 2026

Viewed by 383

Abstract

Obolodiplosis robiniae (Haldeman) is a specialist herbivore of Robinia pseudoacacia L., and its infestation is closely associated with tender leaf tissues. The ability of gravid females to recognize suitable host tissues is essential for successful oviposition and subsequent population development. Here, we assessed [...] Read more.

Obolodiplosis robiniae (Haldeman) is a specialist herbivore of Robinia pseudoacacia L., and its infestation is closely associated with tender leaf tissues. The ability of gravid females to recognize suitable host tissues is essential for successful oviposition and subsequent population development. Here, we assessed whether leaf age affects the host-selection behavior of O. robiniae and whether volatile organic compounds are associated with this process. Laboratory oviposition assays were used to compare egg deposition on tender leaves and mature leaves of R. pseudoacacia, and Y-tube olfactometer bioassays were performed to evaluate female responses to odors from the two leaf ages. Volatiles released from healthy tender leaves and mature leaves were collected using dynamic headspace sampling and characterized by thermal desorption–gas chromatography–mass spectrometry. Principal component analysis, orthogonal partial least squares discriminant analysis, and variable importance in projection scores were used to compare volatile profiles between leaf ages. Gravid females deposited significantly more eggs on tender leaves than on mature leaves in both choice and no-choice assays. Females also showed a significant olfactory preference for tender-leaf odors when directly offered a choice between volatiles from tender leaves and mature leaves, with 76.47% of responding individuals selecting tender-leaf odors and 23.53% selecting mature-leaf odors. Chemical profiling identified 28 volatile compounds across the two leaf ages, and their composition and relative abundance differed markedly. Among shared compounds, (Z)-3-hexen-1-ol and α-farnesene differed significantly between tender leaves and mature leaves. Multivariate analyses further identified several candidate compounds contributing to leaf age-related volatile differences. These results indicate that leaf age influences both oviposition behavior and odor-mediated host location in O. robiniae. Leaf age-dependent volatile blends may serve as important chemical cues associated with host selection by gravid females and provide a basis for future studies on volatile-mediated management strategies. Full article

(This article belongs to the Special Issue Emerging Trends in Chemical Ecology: Towards Sustainable and Scalable Pest Management Solutions)

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15 pages, 4411 KB

Open AccessFeature PaperArticle

Reference Genes for Expression Analyses by RT-qPCR in Hyblaea puera (Lepidoptera: Hyblaeidae)

by Xinan Li, Ruiyang Qin, Wen Zhang, Fengfan Wang, Ganyu Zhu, Xiaopeng Wang, Hengyu Zhang, Menghui Liu, Liangjian Qu and Hao Yu

Insects 2026, 17(6), 639; https://doi.org/10.3390/insects17060639 - 17 Jun 2026

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Abstract

Hyblaea puera is a major pest of teak and mangroves. Reliable RT-qPCR normalization requires stable reference genes, none of which have been validated in H. puera. In this study, we assessed the expression stability of ten candidate reference genes under different [...] Read more.

Hyblaea puera is a major pest of teak and mangroves. Reliable RT-qPCR normalization requires stable reference genes, none of which have been validated in H. puera. In this study, we assessed the expression stability of ten candidate reference genes under different experimental conditions. Stability was evaluated using the ΔCt method, BestKeeper, NormFinder, and geNorm, and a comprehensive stability ranking was generated using the RefFinder online tool. Our results indicated that amplification efficiencies ranged from 91.67% to 100.82%, with R² values exceeding 0.9901. The optimal reference gene combinations varied by condition: Ribosomal Protein L27 (RPL27) and Ribosomal Protein L10 (RPL10) for temperature treatments; Actin and RPL10 for larval instars; Ribosomal protein S5 (RPS5) and Elongation factor-1α (EF-1a) for adult sexes; RPL10 and EF-1a for tall developmental stages; RPL10 and RPS5 for tissues; as well as EF-1α and Actin for all combined conditions. Finally, the expression profiles of target gene Lethal were evaluated, and the outcomes further confirm the importance of selecting fitting reference genes for normalization of qRT-PCR data. These results provide the evaluated reference gene sets for H. puera, facilitating more accurate RT-qPCR normalization in future molecular studies of host plant adaptation (teak vs. mangroves), temperature tolerance, and larval development in this pest. Full article

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

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12 pages, 5783 KB

Open AccessArticle

Effects of Microplastics and Cadmium on the Leptinotarsa decemlineata (Coleoptera: Chrysomelidae): An Evaluation Using a Two-Sex Life Table

by Boling Liu, Yunhui Liu, Yi Zhang, Bingyu He, Yulin Gao and Chao Li

Insects 2026, 17(6), 638; https://doi.org/10.3390/insects17060638 - 17 Jun 2026

Viewed by 338

Abstract

This study utilized the age-stage, two-sex life table method to evaluate the toxic effects of polyethylene microplastics (PE, 300 mg/kg) and cadmium (Cd, 30 mg/kg), both individually and combined, on Leptinotarsa decemlineata. Compared to controls, all treatments significantly prolonged larval development and [...] Read more.

This study utilized the age-stage, two-sex life table method to evaluate the toxic effects of polyethylene microplastics (PE, 300 mg/kg) and cadmium (Cd, 30 mg/kg), both individually and combined, on Leptinotarsa decemlineata. Compared to controls, all treatments significantly prolonged larval development and reduced survival, lifespan, and fecundity. The combined exposure (PE + Cd) exerted the strongest inhibition: the total pre-adult developmental duration (TPOP) increased by 18.8% (38.00 days), while the intrinsic growth rate (

r

) dropped by 59.0% to 0.0273 d⁻¹. Additionally, the net reproduction rate (

R_{0}

) and fecundity fell to their lowest levels (5.08 and 19.06, respectively), significantly lower than in single-treatment groups. Age-stage life expectancy analysis confirmed severe survival pressure in the combined group, evidenced by a 30% reduction in first-instar survival and a 14-day shortened adult lifespan. These findings demonstrate the synergistic toxicity of PE and Cd co-contamination, providing critical data for ecological risk assessment in the “soil–plant–herbivore” system and integrated pest management strategies. Full article

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

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14 pages, 921 KB

Open AccessArticle

Potential Effect of Magnetic Field on Spodoptera littoralis (Lepidoptera: Noctuidae): Development, Malform, Reproductivity and DNA Mutagenicity

by Wael Elmenofy, Abd-Elkhalik M. Husseen, Mervat A. Kandil, Hossam S. El-Beltagi, Hosny H. Kesba and Mohamed A. M. Atia

Insects 2026, 17(6), 637; https://doi.org/10.3390/insects17060637 - 17 Jun 2026

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Abstract

Spodoptera littoralis (Boisduval, 1833) is one of the most destructive insect pests in Egypt and worldwide. This study was conducted to investigate the impact of exposure to a magnetic field (MF) of 180 milliTesla on the developmental phases of S. littoralis, as [...] Read more.

Spodoptera littoralis (Boisduval, 1833) is one of the most destructive insect pests in Egypt and worldwide. This study was conducted to investigate the impact of exposure to a magnetic field (MF) of 180 milliTesla on the developmental phases of S. littoralis, as well as malform, reproductivity, and genomic DNA mutagenicity. The obtained results concluded that the exposure of S. littorelis to MF significantly affected the malformation and mortality rates in both larvae and pupae. The MF extended the duration of the pupal stage from approximately 0.8 to 5.9 days compared to the untreated pupae. The adult emergence percentages decreased to 68.0 and 74.0% upon exposure to a magnetic field for 60 and 40 min, respectively. The female fecundity decreased by increasing the exposure duration, yielding (7–10), (6–10), and (3–8) mass eggs per female upon exposure intervals of 20, 40, and 60 min, respectively. Meanwhile, the hatchability percentage diminished with prolonged exposure time, recording 77%, 60%, and 53% for MF exposure durations of 20, 40, and 60 min, respectively, compared to 91% hatchability in the control trial. The genetic characterization employing inter-simple sequence repeat (ISSR) markers disclosed genetic mutagenicity, exhibiting a similarity matrix range from 61.6% to 74.1% for larvae, 59.8% to 68.5% for adults, and 36.2% to 49% for pupae, indicating genetic alteration in treated insects. Hence, these findings highlight the implications and prospective application of a magnetic field of 180 milliTesla as a unique approach in integrated S. littoralis control frameworks. Full article

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

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19 pages, 1422 KB

Open AccessSystematic Review

A Systematic Review of Biological Control Agents, Plant Extracts and Cover Crops or Intercropping for the Control of Leucoptera coffeella (Lepidoptera: Lyonetiidae)

by Maguintontz Cedney Jean-Baptiste, Flávio Roberto Mello Garcia, Beatriz Sousa Coelho, Maria Aparecida Castellani, Mateus Pereira dos Santos and Aldenise Alves Moreira

Insects 2026, 17(6), 636; https://doi.org/10.3390/insects17060636 - 16 Jun 2026

Viewed by 403

Abstract

The leaf miner Leucoptera coffeella Guérin-Méneville & Perrottet, 1842 (Lepidoptera: Lyonetiidae), is a major pest of coffee plants (Coffea spp.) worldwide. It is recognized for its widespread occurrence in coffee plantations and the quantitative and economic losses it causes to coffee production, [...] Read more.

The leaf miner Leucoptera coffeella Guérin-Méneville & Perrottet, 1842 (Lepidoptera: Lyonetiidae), is a major pest of coffee plants (Coffea spp.) worldwide. It is recognized for its widespread occurrence in coffee plantations and the quantitative and economic losses it causes to coffee production, especially in regions with higher temperatures and greater water deficits. We evaluated historical and current research approaches to leaf miner management, establishing current knowledge through a systematic review of research on biological control agents (BCAs), plant extracts and cover crops or intercropping for L. coffeella control, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We conducted a systematic review of research findings from 1980 to 2025, developing a set of a priori criteria for subsequent replication of the review process. This review covers 130 publications, of which 28 met the inclusion criteria. The selected studies were conducted in five countries, although 75.00% of the studies were from Brazil. The BCAs accounted for 60.71%, followed by plant extracts (32.17%) and cover crops or intercropping (7.15%). Field studies were predominant, prioritizing diagnostic studies, surveys, studies on alternative control methods, and finally studies on BCAs, providing an effective solution. The limitations and prospects for their management were analyzed, and we highlighted recommendations that will improve future studies. Full article

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

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19 pages, 12412 KB

Open AccessArticle

Climate Change Impacts on Suitable Habitats of the Endangered Parnassius imperator, an Alpine Butterfly Endemic to China

by Keshi Ma, Yongli Wang, Weili Ding, Yiran Ma, Xiaojiao Tang, Jing Han, Junting Li, Xinru Li, Suqin Shang and Mingsheng Yang

Insects 2026, 17(6), 635; https://doi.org/10.3390/insects17060635 - 16 Jun 2026

Viewed by 244

Abstract

Climate change and habitat loss pose severe threats to the survival of alpine butterflies worldwide. Parnassius imperator is a rare, endemic, and endangered butterfly in China, yet the spatiotemporal dynamics of its suitable habitats under climate change remain largely unknown. In this study, [...] Read more.

Climate change and habitat loss pose severe threats to the survival of alpine butterflies worldwide. Parnassius imperator is a rare, endemic, and endangered butterfly in China, yet the spatiotemporal dynamics of its suitable habitats under climate change remain largely unknown. In this study, we applied ensemble species distribution models to simulate the shifts of its current and future suitable habitats, incorporating bioclimatic variables, elevation, normalized difference vegetation index, and human footprint. Results showed that the current suitable habitats cover 185.87 × 10⁴ km² and are concentrated in western China, mainly regulated by elevation, temperature seasonality (BIO4), precipitation of the wettest month (BIO13), precipitation of the warmest quarter (BIO18), and precipitation of the driest month (BIO14). Under future climate change scenarios, suitable habitats will shrink drastically, even to only 82.16 × 10⁴ km² under SSP585 in the 2070s, with nearly a complete loss of highly suitable habitats. In addition, centroid shift analyses reveal that the distribution centroid will shift eastward. Our findings indicate that suitable habitats will contract significantly, and P. imperator will face a sharply increasing risk of extinction in the future. Considering the overlap between suitable habitats and existing nature reserves, we recommend implementing integrated conservation strategies, including expanding protected areas, establishing long-term monitoring programs, restoring habitats, and strengthening law enforcement and public education. This study provides a scientific basis for the climate-adaptive conservation of P. imperator and other vulnerable alpine insects. Full article

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

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28 pages, 708 KB

Open AccessReview

Major Honey Bee Diseases and Possibilities to Control Them with Essential Oils

by Yordan V. Hristov, Koycho Koev, Tsvetan Tsvetanov and Ralitsa Balkanska

Insects 2026, 17(6), 634; https://doi.org/10.3390/insects17060634 - 16 Jun 2026

Viewed by 394

Abstract

Honeybee colonies are affected by bacterial, fungal, viral, microsporidian, and parasitic diseases that impair brood viability, adult survival, productivity, and beekeeping sustainability. Conventional control relies on sanitary measures, antibiotics where permitted, and synthetic acaricides, but these approaches are constrained by residues, resistance, regulation, [...] Read more.

Honeybee colonies are affected by bacterial, fungal, viral, microsporidian, and parasitic diseases that impair brood viability, adult survival, productivity, and beekeeping sustainability. Conventional control relies on sanitary measures, antibiotics where permitted, and synthetic acaricides, but these approaches are constrained by residues, resistance, regulation, and variable field performance. This narrative review critically evaluates essential oils as alternative or complementary tools against American foulbrood, European foulbrood, varroosis, nosemosis, chalkbrood, and mite-associated viral pressure. Evidence indicates that thymol, carvacrol, eugenol, cinnamaldehyde, and related constituents can show marked antibacterial, antifungal, acaricidal, antioxidant, and host-supportive activity under controlled conditions. However, most bacterial, fungal, and nosemosis data remain laboratory-based, and direct antiviral applications against honeybee viruses are not field validated. The strongest practical evidence concerns thymol-based control of Varroa destructor, where efficacy depends on formulation, release rate, temperature, colony status, and safety margins. Essential oils should therefore be considered components of integrated honeybee health management, not substitutes for established measures. Future studies should prioritize chemical standardization, dose–response testing, colony-level trials, brood and queen safety, sublethal behavior and physiology, gut microbiota, residues, and reproducible delivery systems. Full article

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

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30 pages, 16931 KB

Open AccessArticle

Mechanisms Underlying Male Reproductive Toxicity Induced by Sublethal β-Cypermethrin Exposure in Antheraea pernyi (Guérin-Méneville, 1855) (Saturniidae)

by Xin Chen, Tianyi Zhang, Liang Xu, Junshan Chen, Peifeng Liu, Fengquan Liu, Shiwen Zhao, Miaomiao Chen and Xisheng Li

Insects 2026, 17(6), 633; https://doi.org/10.3390/insects17060633 - 15 Jun 2026

Viewed by 357

Abstract

Pyrethroid insecticides are widely used in agriculture, but their sublethal effects on male reproduction in Antheraea pernyi (Guérin-Méneville, 1855) (Saturniidae) remain largely unknown. Here, we evaluated the effects of sublethal β-cypermethrin exposure (LC₂₀ = 0.0074 mg/L) on gonadal development, testicular morphology, sperm [...] Read more.

Pyrethroid insecticides are widely used in agriculture, but their sublethal effects on male reproduction in Antheraea pernyi (Guérin-Méneville, 1855) (Saturniidae) remain largely unknown. Here, we evaluated the effects of sublethal β-cypermethrin exposure (LC₂₀ = 0.0074 mg/L) on gonadal development, testicular morphology, sperm quantity and function, mating behavior, and post-mating egg traits from the larval to adult stages and investigated the molecular mechanisms using transcriptome sequencing. Insecticide stress impaired testicular development and disrupted spermatogenesis, leading to a 25% reduction in eupyrene sperm bundles, a 10.72% decrease in acrosin activity, and a 16.75% decrease in the curvilinear velocity of apyrene sperm. Mating willingness decreased by 17.78 percentage points, and females mated with treated males produced 20.45% fewer eggs. Transcriptome analysis identified 1193 differentially expressed genes (|log₂FC| > 1, FDR < 0.01). Detoxification and stress response genes (e.g., CYP3A27, GSTD1, ABCB1, and Hsp70) were predominantly up-regulated, while reproduction-related genes (e.g., dnal1, tubb1, ATPsynbeta, far1, JHAMT, mei-41, and dna2) were down-regulated. This study demonstrates that sublethal β-cypermethrin exposure induces male reproductive toxicity in A. pernyi through a “dual-hit” mechanism: persistently activating the detoxification system (leading to energy depletion) while directly suppressing reproductive genes, ultimately resulting in impaired germ cell development, defective sperm function, and reduced fertility. Full article

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

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34 pages, 4346 KB

Open AccessArticle

Metabolic and Gut Microbiome Responses to Paraquat Exposure in Apis mellifera Under Laboratory Conditions

by Natasha Mills, Nantana Mills, Patcharin Phokasem, Giatgong Konguthaithip, Rujipas Yongsawas, Chanon Saksunwiriya, Chainarong Sinpoo, Sahutchai Inwongwan, Sasiprapa Krongdang, Ji-Ho Lee, Churdsak Jaikang and Terd Disayathanoowat

Insects 2026, 17(6), 632; https://doi.org/10.3390/insects17060632 - 15 Jun 2026

Viewed by 1008

Abstract

Paraquat is a widely used herbicide known to adversely affect honeybee physiology; however, its impact on gut-associated biological processes remains poorly understood. Therefore, intricate effects of paraquat on honeybees highlight the need for a comprehensive understanding of its specific biological consequences. This study [...] Read more.

Paraquat is a widely used herbicide known to adversely affect honeybee physiology; however, its impact on gut-associated biological processes remains poorly understood. Therefore, intricate effects of paraquat on honeybees highlight the need for a comprehensive understanding of its specific biological consequences. This study aimed to evaluate the gut microbiome composition and metabolomic profiles of honeybees following oral exposure to sublethal (LD₂₅) and toxic (LD₅₀) doses of paraquat, assessed 48 h post-exposure to represent acute exposure. Survival rate and sucrose consumption were monitored to assess toxicity. Honeybee gut samples were analyzed using 16S rRNA gene amplicon sequencing and metabolomic approaches. Both paraquat treatments resulted in increased mortality (p < 0.0001) and reduced sucrose consumption (p = 0.00503). In contrast, gut bacterial community composition remained largely unchanged (p > 0.05). Metabolomic analysis revealed dose-dependent alterations, particularly in metabolites associated with carbohydrate and energy metabolism, including oxaloacetic acid and pyruvic acid. This study provides the first integration of 16S rRNA gene amplicon sequencing and metabolomic analyses to evaluate the effects of paraquat exposure in honeybees. The findings indicate that paraquat-induced stress primarily exhibits as host metabolic reprogramming rather than changes in microbiome composition. These results provide insights into the mechanisms underlying honeybee responses to herbicide stress and may contribute to the development of strategies for honeybee protection. Full article

(This article belongs to the Special Issue Bees: Physiology, Immunity and Developmental Biology)

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14 pages, 3029 KB

Open AccessArticle

Differential Performance of Vector and Non-Vector Planthoppers on Virus-Infected vs. Mock-Infected Plants

by Guangchao Cui, Pei Li, Somkhit Sengsay, Artisack Seesomphone, Laythong Sisongkham, Kongkham Akhavongsa, Huai Liu and Maolin Hou

Insects 2026, 17(6), 631; https://doi.org/10.3390/insects17060631 - 15 Jun 2026

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Abstract

The southern rice black-streaked dwarf virus (SRBSDV) is transmitted by the white-backed planthopper (WBPH), Sogatella furcifera, but not by the co-occurring brown planthopper (BPH), Nilaparvata lugens. Understanding the influence of virus infection of host plants on the performance of close-related vector [...] Read more.

The southern rice black-streaked dwarf virus (SRBSDV) is transmitted by the white-backed planthopper (WBPH), Sogatella furcifera, but not by the co-occurring brown planthopper (BPH), Nilaparvata lugens. Understanding the influence of virus infection of host plants on the performance of close-related vector and non-vector species is an interesting topic for exploring virus–plant–herbivore interactions. This study investigates how SRBSDV infection of rice plants affects the performance of WBPH and BPH and the plant defense responses. Differential performance of the two planthopper species was observed. On infected plants, WBPH displayed prolonged male nymphal development, increased adult longevity, enhanced feeding, and reduced fecundity, which contrasts the reduced nymph survival and fecundity in BPH. SRBSDV infection triggered an increase in salicylic acid (SA) levels and upregulated the expression of SA-related genes (ICS1 and NPR1) in response to WBPH feeding, but not to BPH feeding. These results show that SRBSDV reshapes the host plant defense in a manner that alters key vector traits favoring virus transmission while impairing the fitness of a competing non-vector, which advances current understanding of virus–plant–herbivore interaction. Full article

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

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16 pages, 10132 KB

Open AccessArticle

Effects of Carbon Dioxide on Hemolymph and Brain Proteomes in Honey Bee Workers (Apis mellifera L.)

by Ying Wang, Beibei Ma and Yu Fang

Insects 2026, 17(6), 630; https://doi.org/10.3390/insects17060630 - 15 Jun 2026

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Abstract

Carbon dioxide (CO₂) is essential in beekeeping practices but its optimal dosage and physiological effects on honey bees remain unclear. This study examined CO₂ tolerance and molecular responses across three developmental stages: newly emerged, nurse, and forager bees, using gradient [...] Read more.

Carbon dioxide (CO₂) is essential in beekeeping practices but its optimal dosage and physiological effects on honey bees remain unclear. This study examined CO₂ tolerance and molecular responses across three developmental stages: newly emerged, nurse, and forager bees, using gradient exposure and proteomic analysis. Newly emerged bees demonstrated the highest CO₂ tolerance. Hemolymph and brain exhibited distinct responses: the cytochrome P450 pathway dominated in hemolymph, while the brain displayed stage-specific strategies. Newly emerged bees activated metabolic reorganization and clearance pathways. Nurse bees strengthened antioxidant defenses, while foragers enhanced amino acid metabolism to produce antioxidant precursors. All stages showed role-specific energy metabolism reprogramming to meet increased post-exposure demands. These findings provide critical data and theoretical foundations for honey bee colony management, transportation, and handling practices. The results also contribute valuable insights to the fundamental biology of other insects. Full article

(This article belongs to the Special Issue Bees: Physiology, Immunity and Developmental Biology)

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20 pages, 2038 KB

Open AccessArticle

Stage-Dependent Predation by Scymnus (Scymnus) folchinii Against Myzus persicae: Functional Response and First-Instar Prey Sharing

by Yu-Cheng Fang, Xiao-Li Mao, Yang Zhang, Xin-Yi Wang, Tong-Xian Liu and Yi Feng

Insects 2026, 17(6), 629; https://doi.org/10.3390/insects17060629 - 15 Jun 2026

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Abstract

Small scymnine coccinellids, including many Scymnus species, are common aphid predators, but stage-specific feeding data are still limited for many species. We investigated feeding behavior, first-instar prey sharing, stage-specific consumption, and functional responses of Scymnus (Scymnus) folchinii (Canepari) on third-instar Myzus persicae nymphs [...] Read more.

Small scymnine coccinellids, including many Scymnus species, are common aphid predators, but stage-specific feeding data are still limited for many species. We investigated feeding behavior, first-instar prey sharing, stage-specific consumption, and functional responses of Scymnus (Scymnus) folchinii (Canepari) on third-instar Myzus persicae nymphs on chili pepper seedlings. Larvae showed feeding behavior consistent with extra-oral digestion, whereas adults consumed aphids by direct mastication. In the single-prey first-instar assay, prey sharing occurred in all 15 arenas; the period during which two or more larvae fed on the same aphid lasted a median of 31.0 min and accounted for 84.8% of the observed feeding period. Aphid consumption varied with predator stage, exposure time, and initial aphid density. At the highest tested density of 16 aphids, third- and fourth-instar larvae and adults left few aphids alive after 24 h in the seedling micro-arena. Logistic regression diagnosed Type II responses only for adults at 1 h, whereas AIC-based model comparison selected Rogers’ Type II in 15 of 18 stage-by-duration combinations. Short exposures indicated higher attack rates and shorter handling times in fourth instars and adults, whereas longer exposures were affected by prey depletion and satiation. These results show clear stage dependence in aphid consumption by S. folchinii and justify further testing on larger plants and under field conditions. Full article

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

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