Search Results (2,460)

Juvenile hormone (JH) analog insecticides are widely used in pest management because of their ability to disrupt insect growth and metamorphosis; however, the molecular mechanisms linking endocrine disruption to metabolic dysregulation remain incompletely understood. In addition to their established roles in diapause and developmental regulation, JH signaling pathways have also been implicated in carbohydrate and lipid metabolism. In the present study, we investigated the effects of two JH analogs, pyriproxyfen and hydroprene, on the migratory locust, Locusta migratoria, with particular emphasis on lipid metabolic regulation and the function of midgut-enriched fatty acid-binding protein gene (Mg-FABP). Bioassays were performed to evaluate insecticidal activity, and transcriptomic analyses were conducted to identify differentially expressed genes associated with endocrine signaling and lipid metabolism. Functional characterization of Mg-FABP was further performed using RNA interference (RNAi) and Oil Red O staining assays. In addition, the tertiary structure of LmMg-FABP was predicted using AlphaFold 3, and molecular docking analyses were carried out to investigate its interactions with fatty acid ligands. Both pyriproxyfen and hydroprene caused approximately 70% mortality in locust nymphs and induced significant transcriptional changes in pathways related to hormone signaling and lipid metabolism. Transcriptomic analysis revealed pronounced downregulation of Mg-FABP following JH analog exposure. RNAi-mediated silencing of Mg-FABP significantly reduced lipid droplet accumulation in the fat body, indicating that Mg-FABP plays an essential role in lipid transport and metabolic homeostasis in L. migratoria. Structural analyses further demonstrated that LmMg-FABP possesses a conserved tertiary structure highly similar to FABP homologs from other insect species. Molecular docking identified key amino acid residues involved in fatty acid binding and suggested that hydrophobic interactions are critical for ligand stabilization within the binding cavity. Collectively, our findings demonstrate that pyriproxyfen and hydroprene disrupt insect development not only through endocrine imbalance but also through perturbation of Mg-FABP-associated lipid metabolic pathways. This study provides new mechanistic insight into the coordinated interaction between hormonal signaling and lipid metabolism during JH analog exposure and identifies FABP-mediated lipid transport as a potential molecular target for the development of more selective insect growth regulators. Full article

Insect larvae are naturally part of the diet of farmed animals, for instance poultry, pigs, and fish. Thus, the black soldier fly, Hermetia illucens (Linnaeus, 1758) (Diptera: Stratiomyidae) has been grown for use as a source of protein in animal feed. Black soldier fly larvae (BSFL) feed on various organic materials and bioaccumulate the nutrients obtained from the organic materials. This results in BSFL with protein content ranging from 25 to 60% depending on the type of organic material fed. Feeding strategies customized for optimizing BSFL growth and protein deposition are essential for sustainably increasing the production of BSFL to meet the growing demand for their use in animal feed. Feeding strategies for sustainable BSFL production should: ensure nutrient utilization efficiency to optimize BSFL growth and protein deposition; use readily available local organic material of good nutritional quality, safe, and acceptable for use in the animal feed industry; ensure economic and environmental sustainability; and adhere to existing legislature. While substantial information on feeding BSFL is available in different data sources, the literature mainly focuses on increasing BSFL production without integrating sustainability issues, especially economic and environmental sustainability. The objective of this review was to synthesize and consolidate existing information on feeding strategies for BSFL production from different sources and point out sustainable feeding strategies, existing knowledge gaps, and aspects that require further research. The purpose of the review is to provide information on feeding practices for the sustainable production of BSFL to meet the growing demand for BSFL in animal feed. This will contribute to improved food security, environmental management, and job creation. BSFL can feed on mixed organic material food sources more efficiently, reducing the volume of the food by up to 72%, while bioaccumulating the nutrients better than when feeding on individual organic sources such as fruit or vegetable waste. Full article

Choriogenesis, the final stage of oogenesis in insects, is a highly coordinated developmental process responsible for the formation of the chorion (eggshell), a specialized multilayered extracellular matrix that protects the embryo and mediates essential physiological functions. Despite its fundamental importance for reproductive success and species survival, the mechanisms underlying chorion biogenesis remain incompletely understood across insect taxa. This review provides an updated synthesis and integrated view of choriogenesis, including cellular, molecular, biochemical, and structural perspectives. We examine the role of follicle cells in chorion formation, the regulatory mechanisms governing chorion gene expression, and the biochemical composition of the eggshell, including proteins, lipids, and carbohydrates. In addition, we compare the structural diversity of the chorion across insect taxa, highlighting both conserved multilayered organization and lineage-specific adaptations in surface morphology and internal architecture. Full article

Aphis craccivora is a major piercing–sucking insect pest in faba bean (Vicia faba L.) production and severely restricts yield and quality. To identify aphid-resistant genetic resources and clarify the key physiological and biochemical mechanisms underlying resistance and susceptibility, 937 faba bean germplasm accessions were evaluated using a stepwise strategy comprising natural field screening, precise net-house re-screening, laboratory validation based on aphid life-table parameters, and physiological and biochemical characterization of representative resistant and susceptible accessions. After final laboratory validation, three resistant and three susceptible accessions were selected and subjected to aphid feeding for 0 h (CK), 36 h, and 72 h. Eleven physiological and biochemical traits were dynamically analyzed, including the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and phenylalanine ammonia-lyase (PAL), as well as the contents of soluble protein, soluble sugar, free amino acids, tannins, total phenolics, flavonoids, and lignin. Three stable aphid-resistant accessions were ultimately identified. Laboratory life-table analysis showed that the net reproductive rate of aphids on resistant accessions was significantly lower than that on susceptible accessions, with R₀ decreasing from 53.63 to 25.08, representing a reduction of 53.2%. The intrinsic rate of increase decreased by 26.7%, whereas the mean generation time increased by 10.7%, confirming the reliability of the screening results. Physiological and biochemical analyses showed that aphid feeding induced significant and time-dependent increases in SOD, POD, CAT, and PAL activities and in tannin, total phenolic, flavonoid, and lignin contents in resistant accessions, whereas these defense responses were weak in susceptible accessions. In contrast, susceptible accessions showed abnormal accumulation of soluble sugars and free amino acids, whereas resistant accessions maintained these nutrients at low levels. Lignin exhibited both constitutive and inducible defense characteristics in resistant accessions and emerged as a prominent candidate indicator for aphid resistance in faba bean. This study establishes an effective technical pipeline for screening aphid-resistant faba bean germplasm and reveals a coordinated defense network involving antioxidant enzymes, phenylpropanoid metabolism, secondary metabolites, and physical barriers. These findings provide elite parental germplasm and theoretical support for aphid-resistance breeding in faba bean. Full article

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

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

Agri-food by-products (BP) and BP-derived fractions are increasingly recognized as sources of functional and nutritional compounds (e.g., dietary fibers, proteins, waxes, phytosterols, phenolics, carotenoids) that can be upcycled into high-value food ingredients, to improve the sustainability of agri-food chains. This review provides a wide-ranging vision of the potential use of BP and BP-derived fractions in OG formulations, emphasizing the roles they can play (e.g., structuring agents, stabilizers, surfactants, physical scaffolds, fillers, sources of antioxidants), while offering mechanistic insights and science-based perspectives to support the rational design of tailor-made OGs for specific food applications. Particular attention is given to emerging areas including plant-based and hybrid products, and the valorization of insect BP and co-products. Finally, key gaps limiting BP-based OG design and application (e.g., effects on crystallization, interfacial phenomena, dispersion, scaffold/filler behavior, etc.) are identified and translated into a research roadmap and design guidelines for the formulation of tailor-made, scalable BP-based OGs. Full article

The use of insect-based protein sources in aquaculture is gaining increasing attention with Hermetia illucens (black soldier fly, BSF) larvae meal representing a promising substitute to fishmeal (FM). This study evaluated the effect of partial dietary inclusion of BSF meal (BSF0, BSF2.5, BSF5, BSF10%) on the volatilome of rainbow trout (Oncorhynchus mykiss) fillets, before and after cooking, using gas chromatography–mass spectrometry (GC–MS) and a metal oxide sensor-(MOX)-based device. Fish were fed diets with increasing BSF inclusion, and both raw and cooked fillets were analyzed to assess changes in volatile organic compounds (VOCs). GC–MS enabled the identification and semi-quantitative analysis of VOC classes, while MOX sensor responses were processed using Linear Discriminant Analysis (LDA) to assess discrimination among dietary treatments. Results showed that BSF inclusion influenced the volatile profile, with clearer separation at higher inclusion levels (BSF5–BSF10%), especially in cooked fillets. Thermal processing enhanced these differences. GC–MS analysis revealed a reduction in aldehydes and ketones and an increase in carboxylic acids with higher BSF inclusion. Key compounds such as hexanal and heptanal decreased, indicating changes in lipid-derived volatile pathways. Overall, the integration of GC–MS and MOX sensors proved effective in detecting diet-induced changes, supporting their application as effective and reliable tools for quality assessment in aquaculture products, with potential implications for sensory quality that should be further confirmed through dedicated sensory studies. Full article

Mitochondrial genomes are widely used in insect taxonomy and phylogenetics, but their signals may conflict with morphology and nuclear genomic evidence because the mitochondrial genome represents a single maternally inherited locus. Here, we assembled complete mitochondrial genomes of four pygmy grasshoppers, Zhengitettix transpicula, Formosatettix sp., Gibbotettix parvipulvillus, and Bolivaritettix sp., using PacBio HiFi reads. The four mitogenomes ranged from 15,152 to 17,976 bp and contained the typical 37 mitochondrial genes. Mitochondrial phylogenies inferred by maximum likelihood and Bayesian methods were topologically identical and recovered several well-supported tetrigid relationships, including a close relationship between Formosatettix sp. and Bolivaritettix sp. However, Z. transpicula was unexpectedly placed near Macromotettixoides rather than close to other Zhengitettix representatives. In contrast, a morphology-based tree recovered Z. transpicula with Z. triangularis, and comparison with a published nuclear single-copy ortholog tree based on 1962 loci supported a non-mitochondrial placement of Zhengitettix inconsistent with the anomalous mitochondrial position of Z. transpicula. Independent assembly from the original HiFi reads, read-depth inspection, protein-coding gene checks, and nuclear-genome screening for NUMT-like sequences supported the authenticity of the assembled Z. transpicula mitogenome. These results document mito–nuclear and cyto-morphological discordance in Tetrigidae and highlight the need for integrative interpretation of mitochondrial phylogenies in taxonomically complex insect groups. Full article

The cell envelope of Gram-positive bacteria is a primary target of host immune defenses and antibiotics, and its stability is influenced by environmental factors, including the availability of the divalent cations Mg²⁺ and Ca²⁺. Alanine also plays a critical role in cell envelope integrity, contributing to peptidoglycan cross-linking, D-alanine modification of teichoic acids, and protein synthesis. However, how these factors functionally interact to maintain envelope stability in S. aureus remains unclear. Here, we demonstrate that growth of S. aureus under Mg²⁺-limited and Ca²⁺-limited conditions requires increased alanine uptake mediated by the transporter AapA. Loss of AapA results in increased cell lysis and impaired growth under cation-limited conditions, and removing alanine from the growth medium phenocopies these aapA mutant defects. Alanine limitation increases susceptibility to the detergent Triton X-100 and the membrane-targeting antibiotic daptomycin, consistent with defects in envelope stability. Furthermore, aapA function contributes to bacterial fitness in insect and murine infection models. Together, these findings indicate that Mg²⁺, Ca²⁺, and alanine play overlapping roles in stabilizing the S. aureus cell envelope, pointing to AapA as a target that may leveraged to enhance antimicrobial efficacy. Full article

Balancing of macronutrient intake assumes that animals change their food preferences to increase consumption of the deficient nutrients and/or decrease consumption of nutrients in excess. Harvestmen are generalist predators that consume mostly soft-bodied insects, but they supplement this with plant-derived food such as berries (omnivory). In spite of this, they are often carbohydrate-limited in their natural habitats. As aphids have higher sugar content than most other insect prey, they are a potential source of sugar. We hypothesized that sugar-deficient harvestmen have increased preference for aphids relative to other insect prey (fruit flies) and consume more aphids than sugar-satiated harvestmen. Likewise, we hypothesized that protein-deficient harvestmen would show increased consumption of aphids relative to a pure sugar source (dried grape pulp). The former hypothesis was confirmed but the latter was not. Carbohydrate-deprived harvestmen (Leiobunum gracile) consumed 1.9 times more aphids than nutritionally balanced ones (p = 0.0004). Consumption of dried grape was increased in carbohydrate-deficient harvestmen, while protein deficiency did not increase consumption of aphids. These results indicate that aphids may be used as a carbohydrate source if no better alternative is available, but they are unable to relieve a deficiency in protein. We suggest that carbohydrate deprivation in predators may enhance aphid control. Full article

Aging-associated dyslipidemia and chronic low-grade inflammation contribute to atherosclerosis and cardiovascular risk. As a blend of long-chain aliphatic alcohols, policosanol from insect wax (PIW) has been documented to regulate lipid metabolism. However, the effects of PIW on atherosclerosis remain insufficiently characterized. In this study, ApoE^−/− mice fed a high-fat diet were concurrently administered PIW (75 and 150 mg/kg) for eight weeks. PIW was associated with weight gain reduction and improvement in lipid profile, particularly a decrease in triglycerides and total cholesterol. PIW also lowered circulating inflammatory biomarkers (IL-6, TNF-α, and C-reactive protein). Histopathological analyses revealed attenuated hepatic injury and reduced aortic lipid deposition and lesion features. In parallel, PIW reduced serum endothelin-1 and oxidized LDL levels and modulated aortic ET-1, MMP-9/TIMP-1 balance, and LOX-1/NF-κB-related protein signals. Notably, as PIW was administered concurrently with high-fat diet induction, these findings should be interpreted within a preventive intervention framework. Collectively, PIW help attenuate HFD-associated atherosclerotic features and hold promise as a functional food ingredient for cardiovascular health and healthy aging. Full article

In many parasitoid insects, especially hymenopteran parasitoids, venom is delivered around oviposition to override host physiology. Once viewed as a narrowly immunosuppressive secretion, parasitoid venom is now recognized as a multifunctional effector system targeting host immunity, development, metabolism, and behavior. This review synthesizes the venom apparatus, identification strategies, mechanisms of host manipulation, evolutionary processes, and biocontrol prospects, drawing primarily on Hymenoptera. A consistent pattern emerges: comparable host phenotypes arise from divergent molecular scaffolds, indicating functional rather than molecular convergence. Mechanistic evidence is strongest along six interlocking axes: inhibition of the prophenoloxidase cascade and melanization, disruption of cellular and humoral immunity, developmental arrest, metabolic reprogramming, and neuromuscular or behavioral manipulation. Outside Hymenoptera, the coleopteran ectoparasitoid Dastarcus helophoroides offers one of the clearest comparative cases: parasitization inhibits host melanization, alters phenoloxidase activity, and reduces antibacterial activity and circulating hemocyte abundance. As of today, fifty putative venom-like candidate proteins have been identified from larval whole-body proteomics, yet the secretory tissue remains anatomically unresolved, and no individual effector has been functionally validated. The central challenge is therefore the transition from candidate catalogs to mechanistically resolved repertoires, particularly outside Hymenoptera. Closing this gap will be important for evolutionary inference and the rational development of venom-based biocontrol tools. Full article

Holotrichia parallela is a globally distributed soil-dwelling pest that poses a major threat to peanut cultivation in China. Neuropeptides, as critical signaling molecules, regulate multiple physiological and behavioral processes in insects and represent highly promising targets for pest management. To date, the functional characteristics of neuropeptides in H. parallela remain unreported. In this study, we isolated and cloned one NPF and one NPFR gene, respectively. Bioinformatics analysis revealed that alternative splicing of the NPF gene produces two transcript variants, NPFa (255 bp) and NPFb (369 bp). The NPFR gene spans a length of 1188 bp, encoding 395 amino acids that contain seven α-helical transmembrane domains, indicating that it belongs to the family A G protein-coupled receptor (GPCR) family. Spatiotemporal expression profiles demonstrated that NPF was most abundant in the adult brain, whereas NPFR was highly enriched in the brain and antennae. NPF expression peaked in second-to-third-instar larvae, while NPFR was highly expressed in eggs. Starvation stress significantly upregulated the expression of both genes. RNA interference (RNAi)-mediated silencing of NPF and NPFR significantly reduced food intake, female fecundity, and glycogen content in adults. These findings enhance our understanding of insect neuropeptides signaling networks and support the development of behavior-based pest control strategies. Full article

Sungaya inexpectata is a tropical stick insect endemic to the Philippines, providing a useful system for investigating cold responses in tropical ectotherms. In this study, we exposed individuals to low temperature (8 °C) and normal temperature (25 °C) and characterized their transcriptomic responses. A total of 1656 differentially expressed genes were identified, including those involved in energy metabolism, cuticular proteins (CPs), and heat shock proteins. Since CP-related genes were notably enriched, we focused on this family. qPCR assessment provided preliminary expression profiles for selected candidate CP genes. Using comparative transcriptomics with eight New Zealand alpine stick insect species, we reconstructed the phylogeny of major CP families and annotated their conserved domains. Clade analysis revealed significant positive selection in the CPAP3-3 gene. In summary, this study reveals the transcriptional response of cuticular protein genes in S. inexpectata under cold exposure at 8 °C. These findings provide preliminary transcriptional data for understanding how this species responds to low temperature. Full article