Genetic modification via gene editing has become a widely adopted and demonstrably effective method in functional gene research within entomology. However, the optimal efficiency and simplicity of delivering exogenous guide RNA-clustered regularly interspaced short palindromic repeats-associated protein 9 complexes into target tissues are crucial for successful gene editing. The Receptor-Mediated Ovary Transduction of Cargo (ReMOT) strategy, which simplifies the delivery process, target-site selection, technical requirements, and delivery cost compared with embryonic microinjection, enabling efficient editing at the germline level, is gaining increasing attention. Although the feasibility and advantages of this technique have been demonstrated in various insect species, further optimization of operational details and the overcoming of further bottlenecks are still required. This review focuses on advances in developing ReMOT as a valuable technology, exploring its applicability, rationale for selecting the ovary as a delivery target site, factors influencing its efficiency, and improvement recommendations. The versatility and effectiveness of ReMOT make it a promising method for researchers looking to make precise genetic modifications with greater ease and efficiency.

The escalating demand for sustainable and eco-friendly pest management strategies has raised interest in harnessing the pathogenic potential of microorganisms. Serratia marcescens, a Gram-negative bacterium, has emerged as a potential biological control agent for sustainable pest management. This review critically examines the history, biology, identification, and pathogenicity of S. marcescens strain with their potential application in pest management. The diverse mechanisms employed by the strain to exert control over pests, including the production of metabolites and the induction of systemic resistance in plants, are examined. The review also summarizes the ecological significance and global distribution of S. marcescens associated with the use of S. marcescens in biological control strategies. Furthermore, the usage efficacy of S. marcescens over other conventional chemicals is discussed. A comprehensive understanding of the pathogenic potential of S. marcescens strains as biological control agents is crucial for developing effective and sustainable pest management strategies. This review consolidates current research advances on S. marcescens, and provides insights into the prospects and challenges of using S. marcescens for integrated pest management.

Many animals display physiological and behavioral activities limited to specific times of the day. Certain insects exhibit clear daily rhythms in their mating activities that are regulated by an internal biological clock. However, the specific genetic mechanisms underlying this regulation remain largely unexplored. Mating in the fruit fly Bactrocera dorsalis exhibits a daily rhythm and is dependent on sex pheromones produced in the male rectum. We used transcriptome sequencing and clustered regularly interspaced short palindromic repeats (CRISPR) / CRISPR-associated nuclease 9 techniques to understand whether the daily rhythmicity of mating in B. dorsalis and sex pheromone production in the rectum are regulated by clock genes. The results showed that the production of sex pheromones by B. dorsalis males is rhythmic (low during the day and high at night) and is influenced by clock genes. Knockout of the clock genes cryptochrome 1 (cry1) and timeless (tim) reduced the production of sex pheromones and significantly impaired mating ability in males. In addition, quantitative polymerase chain reaction results from 5 different tissues showed cry1 was highly expressed in the head, whereas tim was highly expressed in both the head and rectum (a key site for male sex pheromone production). Transcriptome analysis confirmed that cry1 (head) and tim (head and rectum) exhibit rhythmic expressions consistent with sex pheromone rhythmicity. These results suggest that cry1 may be related to a central clock neuron (like the suprachiasmatic nucleus), whereas the rhythmic expression of tim in the rectum indicates the potential presence of peripheral oscillators. Our study reveals new targets and ideas for improved control of the fruit fly.

Arthropod melanization is a crucial defense mechanism mediated by a complex cascade of CLIP domain serine proteases (CLIPs). In this study, it was confirmed that microRNA-11903a (miR-11903a) targets Aedes-CLIPB9 (AeCLIPB9) by bioinformatics prediction and dual-luciferase reporter assays. Following intrathoracic injection of miR-11903a agomir and antagomir, Real-time quantitative polymerase chain reaction confirmed that AeCLIPB9 is negatively regulated by miR-11903a. Spatiotemporal expression analysis revealed that miR-11903a is most abundant in 4th instar larvae, followed by pupae and adults, and highly expressed in the wings, head, and midgut of female adults. Following pathogen infection, AeCLIPB9 and miR-11903a exhibited opposite expression trends, indicating their potential roles in mosquito innate immunity. To further investigate the relationship between AeCLIPB9 and miR-11903a, double-strand CLIPB9 was synthesized and RNA interference was performed. Seven-d survival assays revealed that both AeCLIPB9 and miR-11903a were crucial immune factors in fighting pathogens. Finally, longevity assays demonstrated that miR-11903a influenced mosquito lifespan.

Wings are important organs of insects involved in flight, mating, and other behaviors, and are therefore prime targets for pest control. The formation of insect wings is a complex process that is regulated by multiple pathways. The Hedgehog (Hh) pathway regulates the distribution of wing veins, while the Hippo pathway modulates wing size. Any interventions that can manipulate these pathways have the potential to disrupt wing development and could be used for pest control. In this study, we find that overexpression of miR-7 in Drosophila results in smaller wings with disordered veins. Mechanistically, miR-7 directly targets both ci and yki via different mature miRNAs (miR-7-5p and miR-7-3p), thereby disrupting the Hh and Hippo pathways. Importantly, this regulatory mechanism is also observed in another insect species, Helicoverpa armigera. Finally, by utilizing a nanocarrier delivery system, we show that introducing miR-7 via star polycation (SPc) leads to wing defects in H. armigera. In conclusion, these findings uncover that miR-7 inhibits wing formation by targeting both the Hippo and Hh pathways, indicating its potential for use in pest control strategies.

RNA N⁶-methyladenine (m⁶A) modification represents a pivotal epigenetic modification that facilitates the remodeling of gene expression and regulates a variety of biological processes via certain post-transcriptional mechanisms. However, the specific function of RNA m⁶A modification in insect male reproduction remains unclear. In this study, we explored the molecular mechanism by which METTL3/METTL14-mediated RNA m⁶A modification regulates male reproduction in the invasive pest Bactrocera dorsalis. The results showed that BdMettl3 and BdMettl14 were highly expressed in fat body (FB) and male accessory glands (MAGs). Knockout of BdMettl3 or BdMettl14 decreased the expression level of m⁶A in B. dorsalis, resulting in testicular deformities and a significant reduction of viable sperm number. Specifically, BdMettl3 or BdMettl14 knockout reduced the titer of 20-hydroxyecdysone (20E, the active form of ecdysone) in males. The messenger RNA (mRNA) of Disembodied, one of the 20E synthesis genes, was modified by m⁶A, and its expression increased the titer of 20E. The mRNA m⁶A level of Disembodied obviously decreased after the knockout of BdMettl3 or BdMettl14, suggesting that RNA m⁶A modification regulates testis development and fecundity by modulating 20E synthesis. Taken together, this study indicates that METTL3/METTL14-mediated RNA m⁶A modification presents a new regulatory mechanism for male reproduction in B. dorsalis, serving as a potential target for the control of B. dorsalis.

Reproductive diapause is an insect survival strategy in which reproduction temporarily halts in response to adverse environmental changes. This process is characterized by arrested ovarian development and lipid accumulation in females. A reduction in juvenile hormone (JH) biosynthesis is known to initiate reproductive diapause, but its regulatory mechanism remains unclear. Seven up (Svp), a transcription factor from the nuclear receptor family, plays a crucial role in various developmental processes in insects. In this study, using the cabbage beetle Colaphellus bowringi as a model, we observed higher expression of Svp in the heads of female adults under reproductive photoperiodic conditions (short-day [SD]) compared to diapause conditions (long-day [LD]). RNA interference-mediated knockdown of Svp in SD females induced typical diapause phenotypes, including ovarian arrest and lipid accumulation. The application of methoprene (ME), a JH receptor agonist, reversed these diapause phenotypes and restored reproduction, indicating that Svp’s regulation of reproductive diapause is dependent on JH signaling. Additionally, Svp knockdown led to the downregulation of JH pathway genes and a reduction in JH titers. Further evidence suggested that Svp regulates the expression of JHAMT1, a critical gene in JH biosynthesis, which determines diapause entry in C. bowringi. These findings suggest that diapause-inducing photoperiods suppress Svp expression, blocking JH production and triggering diapause. This work reveals a critical transcription factor that regulates reproductive diapause initiation through modulating JH production, providing a potential target for controlling pests capable of entering reproductive diapause.

The Drosophila melanogaster (fruit fly) misexpression suppressor of Ras 4 (MESR4) gene encodes a potential transcription factor and plays critical roles in various biological processes, including embryonic development, lipid metabolism, eye–antennal development, and germline stem cell differentiation. However, whether it is involved in modulating intestinal homeostasis remains elusive. In this study, we provide compelling evidence demonstrating that MESR4 is a bona fide regulator in preventing age-onset intestinal leakage and dysbiosis in adult flies. Mechanistically, MESR4 is predominantly located at the nucleus of intestinal cells and controls the expression of bag-of-marbles (bam), thereby restricting the excessive activation of immune deficiency signaling during aging. The silencing of Relish (Rel), which encodes a key transcription factor of the immune deficiency signaling pathway, reverses the beneficial effects of MESR4 in mediating intestinal barrier function and fly lifespan. Collectively, our studies uncover an undescribed function of Drosophila MESR4 in the maintenance of intestinal homeostasis and overall organismal fitness.

As a gene required for sexual development, intersex (ix), functions in concert with the female-specific product of doublesex (dsx) at the end of the hierarchy to facilitate the sex-specific differentiation of sexually dimorphic characters in female Drosophila melanogaster. In the present study, we initially identified the ix homolog in Gryllus bimaculatus, with the detection of a single isoform expressed in both sexes. Phylogenetic analyses and multiple sequence alignment revealed that Gbix exhibited conservation. Here we employed RNA interference (RNAi) and clustered regularly interspaced short palindromic repeats (CRISPR) / CRISPR-associated nuclease 9 (Cas9), respectively, to analyze the functions of Gbix. Our findings indicated that Gbix played a crucial role in the normal development of the embryo and nymph, as well as in the regulation of wing morphogenesis in both sexes. RNAi-mediated knockdown of Gbix resulted in poorly developed ovaries, whereas testicular development was not significantly affected. Nevertheless, CRISPR/Cas9-mediated knockout of Gbix resulted in internal genital defects in both sexes, which ultimately led to a reduction in reproductive capacity in female and male individuals. Our results provide insights into the pleiotropic functions of Gbix in embryogenesis and sexual development, while also advancing our comprehension of sex determination in a hemimetabolous insect species.

Insects represent one of the most evolutionarily successful groups, with their diversity hypothesized to be related to the regulatory roles of Hox genes, a set of related genes encoding homeodomain transcription factors determining the identity of segments along the anterior-posterior axis of the embryo. However, functional insights into the roles of Hox genes in primitive ametabolous insects, which represent the critical transition from aquatic crustaceans to winged insects, have been limited. In this study, we identified complete protein-coding sequences of 10 Hox genes in the Zygentoma Thermobia domestica, and applied clustered regularly interspaced short palindromic repeats (CRISPR) / CRISPR-associated nuclease 9 (Cas 9) mediated gene knockout (KO) to decipher their functions. We found that the roles of pb, Dfd, and Scr are vital in specifying the appendages of the head in T. domestica, and these roles are relatively conserved in crustaceans and winged insects. Antp is essential for the development of the prothorax segment and the first pair of legs in T. domestica. Ubx and abd-A fully repress appendage development in the abdomen of T. domestica, which implies a functional switch from crustaceans to insects. Additionally, the role of ftz in segmenting the abdomen of T. domestica suggests it has acquired new functions in primitive insects, beyond its traditional Hox-like roles. Although KOs of lab, Hox3, and Abd-B did not result in obvious external phenotypic changes, they led to a significant decrease in hatching rates and substantial deviations in daily survival numbers compared to the negative control. These findings underscore the indispensable roles of all Hox genes during the embryonic development of T. domestica. Our study sheds new light on the functional evolution of Hox genes in ametabolous insects and enhances our understanding of the genetic underpinnings of insect development and diversification.

Host expansion facilitates tephritid flies to expand their ranges. Unraveling the mechanisms of host expansion will help to efficiently control these pests. Our previous works showed mitochondrial complex I genes Ndufs1, Ndufs3, and Ndufa7 being upregulated during host expansion of Bactrocera tau (Walker), one of the highly hazardous species of tephritids. However, their roles in the host expansion of B. tau remain unknown. Here, using clustered regularly interspaced short palindromic repeats (CRISPR) / CRISPR-associated nuclease 9 (Cas9) editing system for the first time, a stable homozygous Ndufa7 strain (Btndufa7^−/−), heterozygous Ndufs1 (Btndufs1^+/−), and Ndufs3 strains (Btndufs3^+/−) were obtained from F3 generation of B. tau, after gene knockout. Reduced sizes of larvae and pupae of the Ndufa7 knockout strain were first observed. Notably, the mean values of fitness estimation (pupal numbers, single-pupal weight and emergence rate) and Ndufa7 gene expression in the Ndufa7 knockout strain were slightly reduced on 2 native hosts (summer squash and cucumber), while it sharply decreased on the novel host banana and the potential host pitaya, compared with those of the wild-type strain. Furthermore, the Ndufa7 knockout strain did not survive on the novel host guava. These results suggested that Ndufa7 disturbs the survival on native hosts, expansion to novel hosts, and further expansion to potential hosts of B. tau. Homozygous lethality occurred after the knockout of Ndufs1 or Ndufs3, suggesting that these 2 genes play a role in the early development of B. tau. This study revealed that Ndufa7 is a target gene for the management of tephritids and opens a new avenue for pest control research.

Feeding and molting are particularly important physiological processes for insects, and it has been reported that neuropeptides are involved in the nervous regulation of these 2 processes. Sulfakinin (SK) is an important neuropeptide that is widely distributed among insects and plays a pivotal role in regulating feeding, courtship, aggression, and locomotion. In this study, we investigated the involvement of SK in feeding and molting on a highly notorious pest insect, the fall armyworm, Spodoptera frugiperda. SK transcript levels were found in all larval stages and there was a predominant expression of SK in the brain of 5th instar larvae. By immunostaining, SK was detected in 2 pairs of cells in the median protocerebrum. But during prolonged periods of starvation, there was a significant reduction in SK messenger RNA levels; however, subsequent refeeding led to a notable increase. To investigate the role of SK in feeding and molting, SK was silenced in S. frugiperda larvae through RNA interference. This resulted in a significant increase in food intake, weight gain, and the molting process happened more rapidly in the double-stranded SK-treated larvae compared to the controls. Conversely, injection of sulfated SK peptide (sSK) caused opposite effects. Interestingly, SK-knockdown in larvae resulted in increased levels of 20-hydroxyecdysone and also of the expression of some of it signaling pathway genes. Altogether, this study highlights the important role played by SK in regulating feeding and molting in S. frugiperda.

Cuticular proteins are essential for cuticle formation, molting, and survival in insects. However, functional analysis of cuticular proteins in the melon aphid has been limited. In this study, we identified an endocuticle structural glycoprotein (ESG) AgSgAbd-2-like in the melon aphid Aphis gossypii, which is a member of the RR-1 subfamily of the CPR (cuticular protein containing the conserved Rebers–Riddiford motif) chitin-binding proteins. When double-stranded RNA is delivered epidermally, AgSgAbd-2-like is knocked down, resulting in molting defects and mortality. The expression of AgSgAbd-2-like is comparatively low prior to molting and increases following molting. Ecdysone signaling consistently suppresses AgSgAbd-2-like. Histologically, the endocuticle and whole cuticle are thinner in AgSgAbd-2-like RNA interference (RNAi) aphids, which is a leading cause of molting defects and mortality. Furthermore, knockdown of any other homolog of ESGs, including AgSgAbd-4, AgSgAbd-4-like, AgSgAbd-8-like, and AgSgAbd-9-like, results in molting defects and death, like that by AgSgAbd-2-like RNAi. These results indicate that the melon aphid ESGs are conserved in cuticle formation and could be potential targets for RNAi-based pest management.

Serpins (serine protease inhibitors) constitute a superfamily of proteins with functional diversity and unusual conformational flexibility. In insects, serpins act as multiple inhibitors, by forming inactive acyl-enzyme complexes, in regulating Spätzles activation, phenoloxidases (POs) activity, and other cytokines. In this study, we present the cloning and characterization of Octodonta nipae serpin2 (OnSPN2), a 415 residues protein homologous to Tenebrio molitor 42Dd-like. Notably, OnSPN2 features an arginine residue (R364) at the P1 position, and additional arginine residues (R362, R367) at the P3 and P3′ positions, respectively which is crucial for protease inhibition. Immunohistochemistry (IHC) and Western blot analyses revealed that OnSPN2 is primarily synthesized in plasmatocytes and then released into the plasma to exert its function. RNA interference results indicated that OnSPN2 knockdown may depress serine protease in melanization and remarkably increase the transcript level of Attacin in hemolymph, but its messenger RNA levels were not changed upon immune induction. Reciprocal co-immunoprecipitation assay results confirmed that OnSPN2 binds to OnPPAF1 and OnSP8, indicating its role as a negative regulator in the PO and AMP pathway. Intriguingly, several cathepsin-L isoforms were identified in the OnSPN2 immunoprecipitated samples. The cathepsin-L inhibition assays and protein–protein docking results, identified cathepsin-L as a potential target of OnSPN2. These results indicate that OnSPN2 is produced as an intracellular resident and additionally is associated with the PO and AMP pathway. OnSPN2 represents a multiple defense tool that may provide multiple antiproteolytic functions.

Diapause is a programmed developmental arrest process in insects. Diapause can occur at various stages of insect development and is frequently restricted to a specific developmental stage within a single species. In Bombyx mori, embryonic diapause is elicited by the diapause hormone (DH) and DH receptor (DHR) in diapause strains. Nevertheless, the regulatory mechanism through which BmDHR functions as a G protein-coupled receptor (GPCR), to exert other physiological functions in nondiapause silkworms, remains unclear. In this study, we found that BmDHR had 7 alternative splice isoforms. A knockout experiment confirmed that BmDHR mediated the transduction of diapause signals. Interestingly, the loss of BmDHR caused partial precocious metamorphosis and an embryo-lethal phenotype in nondiapause silkworms. An assessment of global transcriptional patterns revealed that BmDHR knockout affected physiological responses induced by manifold cellular processes, including the Toll/immune deficiency (Imd), Wnt, insulin-like growth factor, Hedgehog and P38/mitogen-activated protein kinase (MAPK) signaling pathways. This study expands our knowledge of the physiological roles for DHR in insect growth and development.

Black soldier fly larvae (BSFL) were reared on mixtures of swine manure and circulating fluidized bed fly ash (CFA) in different ratios. The aim was to evaluate the impacts of insoluble inorganic matter on BSFL and larval frass. The growth performance and nutrient composition of the BSFL were measured under different treatments. The intestinal microbiota structure, morphological characteristics, and total proteolytic activity of the gut were analyzed. The larval frass was tested for nutrients and analyzed using energy-dispersive spectroscopy and scanning electron micrographs. In particular, the surface areas of microparticles from the larval frass (diameter < 0.0074 mm) were measured using Brunauer–Emmett–Teller method. It was found that CFA addition prolonged larval development and reduced the maximum larval weights. The mean larval length, crude protein, and highest larval weight showed negative regression with an increase in the CFA ratio (P < 0.05). Morphological images indicated that physical clogging might be the main influencing factor on larval growth. Moreover, the microbial diversity and complexity in the larval gut increased with CFA addition, but CFA addition had little effect on the composition of dominant phyla or genera (P > 0.05). Finally, the nutrient composition revealed that the frass met the organic fertilizer standard when the CFA addition ratio was less than 7.5%. The optimal addition ratio was 5%, at which the larvae had a more stable and healthier gut environment, but there was less of an effect on larval growth and nutrient composition. Moreover, particles from 5% CFA mixture had the highest surface area.

The gut microbiota has been linked to the pathophysiology of inflammatory bowel disease (IBD). Current animal models are limited in the generation of germ-free animals to evaluate the roles of gut bacteria in intestinal health. Here, we used the honeybee (Apis mellifera) as a model animal to develop colitis-like gut permeability induced by dextran sodium sulfate (DSS) treatment. We found that DSS could increase gut permeability and compromise the mucosal barrier in honeybees, resulting in decreased survival rates, midgut elongation, and intestinal edema. DSS treatment upregulated the expression of wnt-1 and rhomboid and downregulated the pathways of cytochrome P450 (CYP) and the peroxisome proliferator-activated receptor signaling. Moreover, DSS disrupted the structure and functional profiles of the gut microbiota. Our results showed that medications reduced mortality and moderated leaky gut syndrome in DSS-treated bees. Notably, 5-aminosalicylic acid (5-ASA) could attenuate gut permeability in honeybees through activating PPARγ signaling, which mimics the human. Honeybees offer a promising experimental model for investigating the etiology of intestinal diseases and disentangling the roles of gut symbionts in intestinal health.

Aedes albopictus (Ae. albopictus) is widely distributed and can transmit many infectious diseases, and insecticide-based interventions play an important role in vector control. However, increased insecticide resistance has become a severe public health problem, and the clarification of its detailed mechanism is a matter of urgence. This study found that target-site resistance and metabolic resistance could not fully explain insecticide resistance in field Ae. albopictus, and there were likely other resistance mechanisms involved. The 16S and internal transcribed spacer sequencing revealed significant differences in the species compositions of the cuticle surface symbiotic bacteria and fungi between deltamethrin (DM)-resistant (DR) and DM-susceptible (DS) Ae. albopictus. Additionally, the abundances of Serratia spp. and Candida spp. significantly increased after DM treatment. Furthermore, 2 fungi (Rhodotorula mucilaginosa and Candida melibiosica) and 3 bacteria (Serratia marcescens, Klebsiella aerogenes, and Serratia sp.) isolated from DR Ae. albopictus can use DM as their sole carbon source. After reinoculation onto the cuticle surface of DS Ae. albopictus, R. mucilaginosa and C. melibiosica significantly enhanced the DM resistance of Ae. albopictus. Moreover, transcriptome sequencing of the surviving Ae. albopictus after DM exposure revealed that the gene expression of cytochrome P450 enzymes and glutathione-S-transferases increased, suggesting that besides the direct degradation, the candidate degrading microbes could also cause insecticide resistance via indirect enhancement of mosquito gene expression. In conclusion, we demonstrated that the cuticle surface symbiotic microbes were involved in the development of insecticide resistance in Ae. albopictus, providing novel and supplementary insights into insecticide resistance mechanisms.

Ceratitis capitata (Wiedemann) is a cosmopolitan pest of economic importance. It is controlled by using the Sterile Insect Technique (SIT), which involves rearing and release of sterile males destined to mate with wild females, causing generation-to-generation suppression. Medflies are colonized by microorganisms, primarily the Enterobacteriaceae, with the genera Klebsiella and Enterobacter being the most common. Such microbiota contributes to host fitness. During the SIT, diet with antibiotics and irradiation for sterility of adults alter microbiota. We aimed to determine the role of Medfly microbiota on resistance to abiotic stress conditions, evaluating its function under: (i) starvation, (ii) elevated temperatures, and (iii) dry environments. These conditions simulate challenges Medfly may encounter after release, which differ from controlled rearing environments. We compared adult survival between symbiotic and aposymbiotic individuals, under starvation, two thermal regimes (25 and 30 °C) or two humidity regimes (20%–25% and 80%–90% R.H.). Aposymbiotic individuals were obtained after providing them with water containing a mixture of antibiotics and methylparaben. Treatment with antimicrobials effectively reduced the gut microbiota. While starvation had no significant effect on survival, a higher proportion of aposymbiotic individuals died earlier at 30 °C and under dry humidity, with the effect being more pronounced after 48 h. Our results suggest that microbiota plays a role in adaptation of Medfly under environmental stress. We report for the presence of a culturable yeast in the digestive tract of C. capitata, Zygosaccharomyces rouxii. Providing a probiotic adult diet with bacteria and Z. rouxii prior to release could improve SIT outcomes under adverse conditions.

Flower color serves as a key trait for pollinators to locate pollen and nectar, potentially influencing pollinator diversity and pollination effectiveness, which may subsequently increase crop productivity. Based on large-scale cultivation and popularization of colorful flower oilseed rape, we assessed the impact of its flower color variation on pollinator communities and pollination functions. The experiments were conducted with a randomized block design (6 different flower-colored varieties of oilseed rape, each with 5 replications) over 2 consecutive years (2021−2022). Results showed that colorful oilseed rape attracts a diverse array of pollinators and enhances pollination efficiency. Across the 2-year sampling period, we identified insect pollinators from 4 orders, 34 families, and 108 species, with Apis mellifera, Lasioglossum politum, and Delia platura emerging as dominant pollinators. No significant differences in pollinator attraction were observed across different flower colors of oilseed rape. Furthermore, the results revealed that insect pollination significantly enhanced the yield of colorful oilseed rape. However, this effect varied by year. In 2021, the fruit setting rate of the main branch and the fertilization rate of the main and lateral branches in open cages were significantly higher than those in closed cages, which excluded insect-pollinators. However, no significant yield differences were observed between flower colors in response to insect pollination in 2021. In conclusion, colorful oilseed rape can serve as a nectar resource and habitat for pollinators, aiding in the restoration of the diversity and abundance of wild pollinators, improving species turnover, and providing pollination services.

Water striders inhabit the elastic surface tension film of water, sharing their environment with other aquatic organisms. Their survival relies heavily on swift maneuverability and navigation around floating obstacles, which aids in the exploration of their habitat and in escaping from potential threats. Their high agility is strongly based on the ability to execute precise turns, enabling effective directional control. This paper investigates the intricate coordination of leg movements essential for initiating and sustaining turning maneuvers in water striders. We elucidate the distinct roles of each leg in modulating posture and stability during turns, with a focus on the pivotal role of the midlegs in maintaining directional movement. Through analysis of leg accelerations, decelerations, and load distribution, we unveil the spatiotemporal dynamics governing successful turns. Our findings reveal refined turning strategies employed by water striders in varying situations, from narrow to wide turns, characterized by adaptations in their locomotor system, particularly in the widening of the sculling field. Additionally, we report the phenomenon of reverse sculling, a novel escape tactic of water striders. By shedding light on the maneuverability of water striders, this study contributes to a deeper understanding of animal locomotion strategies in aquatic environments.

The fall armyworm (FAW), an important migratory pest native to the Americas, was first detected in a nonnative region (West Africa) in 2016. In the following years, it quickly spread to multiple regions worldwide. FAW exhibits long-distance seasonal migration in both the Americas and Asia, primarily to take advantage of suitable seasonal habitats as they appear along the migratory pathways. Tropical West Africa experiences minimal annual temperature variation and has widely distributed potential year-round habitats, leading us to hypothesize that the migration capacity of FAW populations in this region may be substantially reduced. To test our hypothesis, we assessed the flight performance of FAW collected from Ghana in West Africa with tethered flight mills and compared it to that of a FAW population from southern China. Additionally, we quantified the relationships between morphological characteristics and flight performance of the FAW from Ghana. Based on observed flight behaviors, we categorized FAW into migratory and non-migratory types. The flight capabilities of first-generation Ghanaian FAW bred in the laboratory were similar to that of the field population from Yunnan, Southwest China, with migrants making up the majority. However, after several generations of laboratory rearing, the flight capability of the Ghanaian population significantly declined, primarily due to a marked increase in the proportion of non-migratory individuals. The low correlation between morphological variables and flight duration suggests that genetic factors likely determine most variations in flight propensity. The results of this study indicate that FAW with high migratory capacity in West Africa is likely to pose a threat to crops in eradication zones and neighboring uninvaded areas and may possibly be capable of crossing the Sahara Desert and invading Europe. Therefore, it is crucial to establish comprehensive pest early warning and management systems.

Jewel beetles pose significant threats to forestry, and effective traps are needed to monitor and manage them. Green traps often catch more beetles, but purple traps catch a greater proportion of females. Understanding the function and mechanism of this behavior can provide a rationale for trap optimization. Jewel beetles possess UV-, blue-, green-, and red-sensitive photoreceptors, and perceive color differently from humans. Jewel beetle photoreceptor signals were calculated for tree leaf and tree bark stimuli, representing feeding and oviposition sites of adult jewel beetles respectively. Artificial neural networks (ANNs) were trained to discriminate those stimuli using beetle photoreceptor signals, providing in silico models of the neural processing that might have evolved to drive behavior. ANNs using blue-, green-, and red-sensitive photoreceptor inputs could classify these stimuli with very high accuracy (>99%). ANNs processed photoreceptor signals in an opponent fashion: increasing green-sensitive photoreceptor signals promoted leaf classifications, while increasing blue- and red-sensitive photoreceptor signals promoted bark classifications. Trained ANNs were fed photoreceptor signals calculated for traps, wherein they always classified green traps as leaves, but often classified purple traps as bark, indicating that these traps share salient features with different classes of tree stimuli from a beetle's eye view. A metric representing the photoreceptor opponent mechanism implicated by ANNs then explained catches of emerald ash borer, Agrilus planipennis, at differently colored traps from a previous field study. This analysis provides a hypothesized behavioral mechanism that can now guide the rational selection and improvement of jewel beetle traps.

Oviposition behavior in insects has received considerable attention, but studies have mainly focused on the antennae, neglecting the role of the ovipositor. In this study, we investigated the functional characteristics of the ovipositor in oviposition site selection by the fall armyworm (FAW) Spodoptera frugiperda, a destructive invasive pest of maize and other cereals. In oviposition choice assays females exhibited significant repellency to isothiocyanate (ITC), volatiles specific to non-preferred cruciferous plants. Females retained repellency to ITC or attraction to maize volatiles even after antennae removal. Scanning electron microscopy indicated the presence of olfactory-associated sensilla on the ovipositor. Comparative transcriptome analysis and in vitro functional studies showed that S. frugiperda odorant binding protein 30 (SfruOBP30), exclusively expressed in the ovipositor, displayed a broad sensitivity toward 18 maize volatiles and 10 ITC compounds. Site-directed mutant assay revealed that Ser71 and Ser85 were the key binding sites for SfruOBP30 interacting with ITCs and key maize volatiles, respectively. Silencing the expression of SfruOBP30 resulted in the loss of bias in oviposition of FAW, significantly inhibiting their ability to avoid ITCs and locate the maize substrate. Overall, we propose that the ovipositor does not just seek out advantageous conditions for immature stages but more importantly, avoids potential risks during the oviposition process. Apparently, the involvement of SfruOBP30 plays a critical role in detecting both beneficial and harmful substances during this intricate process.

Foraging behavior is a key factor associated with the success of social insect invasions. Vespula wasps show complex behavioral patterns and social mechanisms associated with foraging, which are directly related to their invasive success in several countries worldwide. Vespula vulgaris (Linnaeus) and Vespula germanica (Fabricius) are invasive wasps, coexisting in Patagonia, showing temporal and dietary overlap. As generalist, opportunistic predators and scavengers with broad diets, these sympatric wasps share similar niches and foraging habits. We analyzed their foraging strategies and interaction, observing the behavior of each species in the presence of workers of the same species, and the other species at a given resource, directly and indirectly. Directly, from a continuous visual record, we observed and recorded the frequency of wasp's behavior at a feeder for 30 min. Indirectly, we conducted pairwise choice tests to compare wasp preference for treated and untreated feeders with visual and olfactory cues simulating the presence of wasps of the same or different species. We found consistent differences between species in aggressiveness. V. vulgaris showed a greater degree of intraspecific agonistic behavior than toward V. germanica, while V. germanica was less aggressive, and intraspecific and interspecific interactions were similar. Also, V. vulgaris preferred landing on baits without visual and olfactory cues simulating wasps presence, while V. germanica preferred baits with cues simulating its own species over baits with cues representing V. vulgaris. Our results suggest that V. germanica prioritize social facilitation as foraging strategy, while for V. vulgaris aggression is the predominant strategy.

Succession is one of the most extensively studied ecological phenomena, yet debates persist about the importance of dispersal and external factors in driving this process. We aimed to quantify the influence of these factors by investigating how wing-related traits evolve across succession of blowfly (Diptera: Calliphoridae) communities in South Brazil. Rat carrion was placed in both forest and grassland habitats, and the associated blowfly communities were documented throughout the decomposition process. Using morphometric analysis, we measured wing and thorax traits and assessed trait changes over succession through mixed models. Our findings revealed that carrion succession follows distinct trajectories in forest and grassland environments. Specifically, we observed that Calliphora lopesi predominantly visited carcasses during the final phase of decomposition, resulting in significant differences in species composition and wing size between habitats. In forests, wing size increased toward the later stages of succession, whereas an opposite trend was observed in grasslands. Notably, these trait patterns were only evident at the species level, indicating that intraspecific trait variation is irrelevant. Stronger dispersers tend to arrive during the later stages of succession, suggesting that dispersal has a negligible role in shaping successional dynamics. Instead, environmental differences between habitats drive trait patterns throughout succession. Our results suggest that community composition in ephemeral resources is governed by deterministic processes and that successional stages can be predicted based on blowfly wing traits. Specifically, the presence of the large-winged C. lopesi indicates late decay, while the small-winged Chrysomia albiceps and Lucilia eximia are indicative of early decay

Polyphagous insect species develop using multiple host plants. Often considered beneficial, polyphagy can also be costly as host nutritional quality may vary. Drosophila suzukii (Matsumura) is an invasive species that can develop on numerous fruit species over the annual cycle. Here, we assessed the contribution of winter-available fruit to the development of seasonal populations of D. suzukii, under fluctuating late winter/early spring temperature regimes. We infested an artificial diet and three suitable fruit species available in winter/early spring (Aucuba japonica, Elaeagnus ×submacrophylla, Viscum album) with D. suzukii larvae under three temperature regimes: constant 20 °C, fluctuating controlled regime of 8–15 °C (12 h of light at 8 °C and 12 h of dark at 15 °C), and uncontrolled outdoor regime during spring. As expected, fly performance was impaired by early spring-like environmental conditions, whatever the development diet, and the winter fruit were suboptimal diets compared to the artificial diet, whatever the thermal regime. However, under cold fluctuating temperature regimes, the ranking of fruit supporting the best performance changed, highlighting the occurrence of physiological trade-offs. Winter-acclimated females preferentially oviposited in A. japonica and/or E. ×submacrophylla, whatever the thermal regime, which does not support the preference–performance hypothesis. This finding is also discussed in the context of D. suzukii management strategies.

The seasonality of Haemaphysalis longicornis in the United States comprises overlapping life stages in the spring and summer. This is partially attributed to the ability of all stages to survive the winter. Physiological condition in ticks refers to nutritional reserve levels and is often used to characterize tick populations. To determine if lipids were suitable for estimating the physiological condition in H. longicornis, lipid content was measured in unfed laboratory-reared ticks for up to 480 d. The results showed that lipids decrease significantly over time in adults (36% at 183 d), nymphs (33% at 63 d) and larvae (28% at 102 d) and could be used to study the population structure of field-collected H. longicornis. Lipids extracted from field-collected ticks (March to October) were measured to determine if different groups or cohorts could be identified during the season. The spring nymph population included high- and low-lipid groups that partially overlapped in April and May. In larvae, the lipid content of ticks in the spring was significantly higher than in the fall, suggesting that active larvae in the early fall do not overwinter. The analysis of lipids in adults showed that high- and low-lipid adults were present throughout the season, suggesting a continuous influx of recently molted adults until the end of the adult season, where only low-lipid ticks are found. The analysis of physiological condition in the Asian longhorned tick demonstrated a complex univoltine structure with some overlap in adults from different years.

The brown planthopper (BPH), Nilaparvata lugens (Stål), is the most important rice pest in China and other East Asian countries. Identifying their source areas and predicting their population dynamics are crucial for managing migratory pests. Northern South China (NSC) is one of the key regions for northward BPH migration and a direct source of BPH in the key rice-growing area of the Lower Yangtze River Valley (LYRV). Hence, this study aimed to explore the environmental drivers affecting the population dynamics of BPH in NSC, and develop models for predicting the immigration levels in the LYRV. Initially, the BPH immigrants in NSC were identified to have mostly originated from northern and north-central Vietnam, Laos, and northeastern Thailand (15°–22° N) in May by using a trajectory analysis approach. The population model showed that immigration size of BPH in NSC in May can be predicted by the temperature observed in February over these source areas combined with the probability of BPH from south-central Vietnam (their principal overwintering region) immigrating to these source areas in March. Subsequently, the immigration size of BPH in NSC in May combined with the onset time of the South China Sea Summer Monsoon (a sign of rain belt movement and arrival of the flood season in China), can be used to predict the immigration level of BPH in the LYRV in July. These 2 prediction models could forecast nearly 2 months in advance, allowing time for effective control measures to be implemented.

Bemisia tabaci is a complex of cryptic agro-economically important pest species characterized by diverse clades, substantial genetic diversity along with strong phylogeographic associations. However, a comprehensive phylogenomic analysis across the entire complex has been lacking, we thus conducted phylogenomic analyses and explored biogeographic patterns using 680 single-copy nuclear genes (SCNs) obtained from whole-genome sequencing data of 58 globally sourced B. tabaci specimens. We constructed both concatenation and coalescent trees using 680 SCNs, which produced highly supported bootstrap values and nearly identical topologies for all major clades. When comparing these concatenation trees with those constructed using mitochondrial cytochrome oxidase I (mtCOI) and mitochondrial genome, we found conflicting phylogenetic relationships, with the later trees recovering fewer major clades. In a separate comparison between concatenation and coalescent trees, particularly those generated using IQ-TREE, they were found to delineate population relationships more effectively than RaxML. In contrast, coalescent phylogenies were proficient in elucidating geographical dispersal patterns and the reorganization of biological species. Furthermore, we provided a strict consensus tree that clearly defines relationships within most clades, laying a solid foundation for future research on the evolution and taxonomy of B. tabaci. Ancestral range estimates suggested that the ancestral region of the complex is likely situated in equatorial Africa, the Middle East, and Mediterranean regions. Subsequently, the expansion occurred into part of the Palearctic and further into the Nearctic, Neotropical, Indomalayan, and Australasian regions. These findings challenge both previous classifications and origin hypotheses, offering a notably more comprehensive understanding of the global distribution, evolutionary history, diversification, and biogeography of B. tabaci.

Many insects and their relatives are renowned for sophisticated compound eyes, which are also preserved in the fossil record. Yet there are other types of eyes, notably the so-called stemmata of holometabolans, such as beetles, bees, and butterflies. Stemmata are not as effective as compound eyes, except in some predatory larvae. Here we report three lacewing larvae with large forward-directed stemmata from Cretaceous Kachin amber, Myanmar. The stemmata are large relative to those of other fossil lacewing larvae, comparable to the simple eyes of modern larvae capable of image formation. The head is very wide in one larva, representing a new type of morphology as demonstrated by a quantitative comparison of the head and stylets of over 400 fossil and extant lacewing larvae. The arrangement of the exceptionally large stemmata of the larvae reported here provides stereoscopic vision. These new specimens demonstrate the convergent evolution of highly developed simple eyes in at least two additional lineages of lacewings, showcasing the enormous diversity of lacewing larvae in the Cretaceous.