Search Results (598)

Root-emitted volatile organic compounds (VOCs) play a critical role in below-ground ecological interactions by mediating communication between plants, pests, and their natural enemies. This study investigates the chemotactic behavior of three slug-parasitic nematode species—Phasmarhabditis papillosa, Oscheius myriophilus, and Oscheius onirici—in response to four carrot (Daucus carota) root-derived VOCs: α-pinene, terpinolene, bornyl acetate, and 2-ethyl-1-hexanol. Using a modified Petri dish assay, infective juveniles (IJs) were exposed to each compound across four concentrations (pure, 1000 ppm, 10 ppm, and 0.03 ppm), and their directional movement was quantified using a chemotaxis index (CI). The results revealed strong species-specific and concentration-dependent patterns. O. myriophilus exhibited the highest motility and repellency, particularly toward bornyl acetate and terpinolene, indicating its potential for use in VOC-guided biocontrol strategies. O. onirici showed moderate but consistent attraction to most VOCs, while P. papillosa exhibited generally weak or repellent responses, especially at higher concentrations. None of the compounds tested functioned as strong attractants (CI ≥ 0.2), suggesting that plant-derived VOCs alone may not be sufficient to direct nematode recruitment under field conditions. However, their integration with other biotic cues could enhance nematode-based “lure-and-infect” systems for sustainable slug control in carrot cropping systems. Full article

Effective control of the parasitic mite Varroa destructor in honey bee (Apis mellifera) colonies relies on integrated pest management (IPM) strategies to prevent mite populations from reaching economic injury levels. Formulations of oxalic acid combined with glycerin may provide a viable summer treatment option in continental Northern climates. This study evaluated the efficacy of oxalic acid and glycerin strips compared to oxalic acid dribble and 65% formic acid when applied in mid-August. Mite levels and colony health parameters were assessed, and honey samples from oxalic acid-treated colonies were analyzed for residue levels. Results showed that the oxalic acid and glycerin strips had a moderate acaricidal efficacy (55.8 ± 3.2%), which was significantly higher than those of 65% formic acid (42.6 ± 3.2%) and oxalic acid dribble (39.5 ± 4.3%), which did not differ between them, suggesting potential for summer mite control. No significant adverse effects on cluster size, worker mortality, queen status, or colony survival were observed. Oxalic acid and glycerin increased the proportion of spotty brood patterns at early timepoints after treatment, but recovery was noted after 45 days of starting the treatment. Similar effects on brood were observed with 65% formic acid 14 days after starting the treatment, with recovery by 28 and 45 days after starting the treatment. No significant differences in oxalic acid residues in honey from the control and treatment colonies were found. Oxalic acid and glycerin strips might help control varroa mite populations, delaying their exponential growth and helping reduce economic losses for beekeepers, but this treatment should be considered as part of an IPM strategy and not a stand-alone method for V. destructor control. Full article

Foot-and-mouth disease (FMD), bluetongue (BT), and Peste des Petits Ruminants (PPR) are major emerging and re-emerging viral infections affecting ruminants. These diseases can threaten livestock health, food security, and economic stability in low- and middle-income countries, including Algeria. However, their dynamics remain mostly unknown, limiting the implementation of effective preventive and control measures. We analyzed outbreak data reported by Algerian veterinary authorities and the WAHIS database from 2014 to 2022 for FMD; from 2006 to 2020 for BT; and from 2011 to 2022 for PPR to investigate their spatiotemporal patterns and environmental drivers. Over these periods, Algeria reported 1142 FMD outbreaks (10,409 cases; 0.16/1000 incidence), 167 BT outbreaks (602 cases; 0.018/1000), and 222 PPR outbreaks (3597 cases; 0.096/1000). Small ruminants were the most affected across all diseases, although cattle bore the highest burden of FMD. BT primarily impacted sheep, and PPR showed a higher incidence in goats. Disease peaks occurred in 2014 for FMD, 2008 for BT, and 2019 for PPR. Spatial analyses revealed distinct ecological hotspots: sub-humid and semi-arid zones for FMD and BT, and semi-arid/Saharan regions for PPR. These patterns may be influenced by species susceptibility, animal movement, trade, and climatic factors such as temperature and rainfall. The absence of consistent temporal trends and the persistence of outbreaks suggest multiple drivers, including insufficient vaccination coverage, under-reporting, viral evolution, and environmental persistence. Our findings underscore the importance of targeted species- and region-specific control strategies, including improved surveillance, cross-border coordination, and climate-informed risk mapping. Strengthening One Health frameworks will be essential to mitigate the re-emergence and spread of these diseases. Full article

Insects’ body coloration may be indirectly influenced by their host plants. Perina nuda (Lepidoptera: Lymantriidae), commonly known as the Banyan Tussock Moth and a serious pest of banyan trees (Ficus spp.) in southern China, exhibits light body coloration during its first- to third-instar stages, with its coloration progressively darkening as it matures, but little is known of the relationship between larval body coloration and host plants. To address this gap, we examined the R (red), G (green), B (blue), and L (lightness) values of the head, dorsal thorax and abdomen, stripe, dorsal mid-line, and tail of larvae fed on different hosts and host endogenous substance by using quantitative image analysis and chemical determination. Our results revealed that larval body coloration exhibited conserved ontogenetic patterns but varied significantly with host species, developmental age, and anatomical region. Redundancy analysis identified chlorophyll-b as the dominant driver, strongly associating with dorsal thorax–abdomen pigmentation. Flavonoids exhibited subthreshold significance, correlating with darker dorsal mid-line coloration, while nutrients (sugars, proteins) showed negligible effects. Linear regression revealed weak but significant links between leaf and larval body coloration in specific body regions. These findings demonstrate that host plant endogenous substances play a critical role in shaping larval body coloration. This study provides a foundation for understanding the ecological and biochemical mechanisms underlying insect pigmentation, with implications for adaptive evolution and pest management strategies. Full article

Sea lice have been a persistent pest of the salmon farming industry for more than 50 years. In this study, we aimed to identify if different strains of Atlantic salmon with discrete long-term lice exposure histories had variable resistance to copepodid attachment and/or different attachment-specific transcriptome patterns. We additionally sought to characterize lice distributions on fins, head, and skin and identify if attachment location influenced transcriptomic profiles of lice. Lice counts were correlated with body size and highest on St. John River (SJR; open ocean-run) relative to Grand Lakes Stream (GLS; 200-year restricted ocean-run) or Sebago Lake (CAS; ~11,000 years landlocked) Atlantic salmon. However, lice density was similar between strains. Skin and fins had expectedly different transcriptomic profiles; however, notable differences were not observed between salmon strains. Variance in lice transcriptomes was minimally affected by attachment location even though lice strongly preferred fins relative to head or body. Attached lice did have different transcriptomic profiles on GLS relative to CAS or SJR. This study cumulatively identified a minimal host evolutionary component for sea lice attachment resistance, although lice behavior post-attachment appeared somewhat affected by strain. Non-uniform settlement distributions and tank-specific variability in lice attachment were observed across populations. Full article

The Colorado potato beetle (Leptinotarsa decemlineata, CPB) is a major pest in potato crops, notorious for its rapid dispersal and insecticide resistance, which are enabled by its robust elytra and flight-capable hindwings. The Miniature (Mi) gene, encoding a protein with a zona pellucida (ZP) domain, is involved in wing development and cuticle integrity, yet its functional role in beetles remains underexplored. In this study, we cloned and characterized the LdMi gene in the CPB and investigated its function using RNA interference (RNAi), morphological analyses, and spectroscopy. LdMi encodes a 146.35 kDa transmembrane protein with a conserved ZP domain, clusters with coleopteran homologs, and exhibits relative conservation across insect species. Expression profiling showed high LdMi transcript levels in the hindwings, the elytra, and the pupal stages. RNAi knockdown in fourth-instar larvae resulted in severe eclosion defects, including malformed wings and reduced adult weight. Scanning electron microscopy (SEM) revealed disrupted elytral patterns and deformed hindwing veins in knockdown individuals. Spectroscopic analyses using Fourier-transform infrared (FTIR) and Raman spectroscopy indicated a reduction in protein–chitin crosslinking and diminished hydrogen bonding, suggesting compromised cuticular integrity. These results highlight the essential role of LdMi in cuticle formation and the surface morphology of the elytra and hindwings, offering new insights into ZP domain proteins in insects. Full article

Heortia vitessoides Moore (Lepidoptera: Pyralidae), the dominant outbreak defoliator of Aquilaria sinensis (Myrtales: Thymelaeaceae, the agarwood-producing tree), poses a severe threat to the sustainable development of the agarwood industry. Current research has preliminarily revealed its biological traits and gene functions. However, significant gaps persist in integrating climate adaptation mechanisms, control technologies, and host interaction networks across disciplines. This review systematically synthesizes the multidimensional mechanisms underlying H. vitessoides outbreaks through the logical framework of “Fundamental Biology of Outbreaks—Environmental Drivers—Control Strategies—Molecular Regulation—Host Defense.” First, we integrate the biological characteristics of H. vitessoides with its climatic response patterns, elucidating the ecological pathways through which temperature and humidity drive population outbreaks by regulating development duration and host resource availability. Subsequently, we assess the efficacy and limitations of existing control techniques (e.g., pheromone trapping, Beauveria bassiana application), highlighting the critical bottleneck of insufficient mechanistic understanding at the molecular level. Building on this, we delve into the molecular adaptation mechanisms of H. vitessoides. Specifically, detoxification genes (e.g., HvGSTs1) and temperature stress-responsive genes (e.g., HvCAT, HvGP) synergistically enhance stress tolerance, while chemosensory genes mediate mating and host location behaviors. Concurrently, we reveal the host defense strategy of A. sinensis, involving activation of secondary metabolite defenses via the jasmonic acid signaling pathway and emission of volatile organic compounds that attract natural enemies—an “induced resistance–natural enemy collaboration” mechanism. Finally, we propose future research directions: deep integration of gene editing to validate key targets, multi-omics analysis to decipher the host–pest–natural enemy interaction network, and development of climate–gene–population dynamics models. These approaches aim to achieve precision control by bridging molecular mechanisms with environmental regulation. This review not only provides innovative pathways for managing H. vitessoides but also establishes a paradigm for cross-scale research on pests affecting high-value economic forests. Full article

The present investigation systematically elucidates the distinct functional specialization within the M1–M3 midgut sections of the significant agricultural pest, Nezara viridula. Employing an integrated transcriptomic analysis, three pivotal discoveries were achieved: (1) each midgut segment possesses unique gene expression signatures; (2) metabolic and signal transduction pathways exhibit coordinated regulatory patterns; and (3) parallel expression changes occur between neuroreceptor (e.g., TACR/HTR) and metabolic enzyme (e.g., GLA/NAGA) genes within identical midgut segments. These data reveal that the M1 region is primarily enriched in metabolic processes and neural signaling; the M2 region emphasizes cellular junctions and immune responses, while the M3 region is mainly responsible for cellular senescence and renewal. These discoveries advance the understanding of feeding adaptation mechanisms in Hemipteran insects and propose a “metabolism–defense–regeneration” functional model for the midgut. The established multi-level analytical framework provides a robust methodology for subsequent dissection of complex biological systems, identification of key molecular targets for functional validation, and for the development of novel pest control strategies. Full article

Exploring host preference and resource partitioning among seed predator species is essential for understanding the coexistence mechanisms and guiding effective forest pest management. This study aimed to elucidate how seed traits influence infestation dynamics and species interactions, focusing on acorn weevils infesting Quercus mongolica. Species identification and clarification of their evolutionary relationships within the Curculio genus were performed through phylogenetic analyses of the mitochondrial cytochrome c oxidase subunit I gene sequences. The seed infestation patterns were assessed by comparing the infestation rates across various seed size classes. Furthermore, the correlations between the seed morphological traits (length, width, aspect ratio, and weight) and weevil abundance were analyzed. The phylogenetic results revealed well-supported monophyletic clades corresponding to Curculio arakawai and Curculio sikkimensis. This confirmed the clear genetic separation between these two distinct weevil species, thereby substantiating the divergence observed in weevil populations correlated with different seed hosts. The infestation patterns revealed the association of weevil species-specific preferences with seed size: C. arakawai predominantly infested larger acorn seeds, whereas C. sikkimensis predominantly infested smaller acorn seeds. C. sikkimensis favored smaller ones. Both species exhibited positive correlations between abundance and seed length and width in larger seeds; however, the seed weight displayed no significant effect. These results indicate niche differentiation mediated by seed size and morphology, which likely reduced interspecific competition and facilitated coexistence. This study elucidates species-specific host selection patterns in acorn weevils and highlights acorn traits as crucial factors shaping seed predator assemblages. The findings provide valuable insights for developing targeted pest management strategies and supporting sustainable oak forest regeneration. Full article

The ladybird beetle, Henosepilachna vigintioctopunctata, is an oligophagous pest with significant economic impact. This pest causes considerable economic damage on numerous Solanaceae crops. Neuropeptides, along with their designated receptors, play a pivotal role in regulating diverse biological processes in insects, presenting a promising avenue for innovative pest management strategies. Herein, the transcriptome of the central nervous system (CNS) of H. vigintioctopunctata was sequenced. Overall, our analysis identified 58 neuropeptide precursor genes, from which 98 diverse mature peptides were predicted. Furthermore, 31 neuropeptide receptor genes belonging to three distinct classes were discovered, along with predictions for their potential ligands. Moreover, the expression patterns of these 58 neuropeptide genes across larval brain tissue, ventral nerve cord, and gut were evaluated using quantitative real-time PCR. Collectively, these findings will significantly contribute to future research focused on understanding the physiological functions and pharmacological characteristics of neuropeptides and their receptors in H. vigintioctopunctata. Ultimately, these insights may facilitate the development of targeted neuropeptide-based solutions for managing this pest affecting solanaceous plants. Full article

The Grapholita dimorpha is one of the significant borer pests that primarily damage plum, pear, and apple trees, often resulting in substantial economic losses in fruit production. However, the potential distribution range of this economically important pest remains poorly understood. In this study, we simulated an optimized maximum entropy (MaxEnt) model to predict the spatiotemporal distribution pattern of G. dimorpha and identified its underlying driving factors. The results indicate that suitable habitats, under current bioclimatic conditions, are mainly distributed in eastern China, northeastern China, Korea, and Japan, covering a total of 273.5 × 10⁴ km². The highly suitable habitats are primarily located in Korea and parts of central Japan, with a total area of 19.8 × 10⁴ km². In future projections, the suitable area is expected to increase by 17.74% to 62.10%, and the suitable habitats are predicted to shift northward overall. In particular, there are more highly suitable habitats for G. dimorpha in China and Japan compared to their predominance in Korea under current climatic conditions. The bio9 and bio18 contribute 51.9% and 20.7% to the modeling, respectively, indicating that the distribution of G. dimorpha may be shaped mainly by the mean temperature of the driest quarter and precipitation of the warmest quarter. In summary, the distribution range predicted, particularly for regions with highly suitable habitats, poses a high risk of G. dimorpha outbreaks, emphasizing the priority of pest monitoring and management. Furthermore, the key bioclimatic variables identified could also provide crucial reference for pest monitoring. Full article

The fall armyworm (Spodoptera frugiperda) is a highly invasive agricultural pest that has caused significant damage to maize and other crops since its initial detection in China in 2019. Understanding its invasion dynamics, migration patterns, genetic diversity, and overwintering capacity is crucial for developing effective pest management strategies. This study investigates these aspects in Shaanxi Province, a critical transitional zone between northern and southern climates in China, from 2019 to 2023. We conducted field surveys in six cities across Shaanxi to monitor the initial infestation of FAW. Migration trajectories were simulated using the HYSPLIT model, integrating pest occurrence data and meteorological information. Genetic analyses were performed on 113 FAW individuals from 12 geographical populations using mitochondrial COI and nuclear Tpi genes. Additionally, an overwintering experiment was conducted to assess the survival of FAW pupae under local winter conditions. The first detection dates of FAW in Shaanxi showed significant interannual variation, with a trend of delayed infestation each year. Three primary migration routes into Shaanxi were identified, originating from Sichuan, Hubei-Chongqing, and Henan. Genetic analysis revealed a predominance of the rice-strain FAW in Shaanxi, with some corn-strain variants in northern regions. The overwintering experiment indicated that FAW pupae could not survive the winter in Shaanxi, suggesting that the region does not support year-round breeding of this pest. This study provides comprehensive insights into the spatiotemporal dynamics and migration patterns of FAW in Shaanxi. The findings highlight the importance of integrated pest management approaches, including monitoring migration routes and genetic diversity, to develop targeted control measures. The inability of FAW to overwinter in Shaanxi suggests that regional climate conditions play a significant role in limiting its year-round presence, which is valuable information for designing early warning systems and sustainable pest management strategies. Full article

Respiration rates in insects are critical for survival and environmental adaptation, being influenced by developmental stages, environmental conditions, and the regulation of mitochondrial protein-coding genes. However, methods for field-based measurements in small-sized insects remain limited. In this study, we established a portable photosynthesis system to quantify respiration rates in five small-sized insects (body length < 8 mm): Acyrthosiphon pisum, Aphis citricidus, Tuta absoluta, Tribolium castaneum, and Bactrocera dorsalis. We tested its effectiveness across life stages and under diverse treatments, including light/dark cycles, insecticides, temperature shifts, starvation, mitochondrial inhibitors, and RNA interference. The system exhibited high sensitivity and reproducibility rates, revealing stage-specific respiration patterns. Various treatments, as well as expression changes in mitochondrial protein-coding genes, significantly affected respiration rates. This study validates the portable system as a reliable tool for insect respiration studies and highlights regulatory networks associated with respiratory plasticity. These findings enhance experimental methodologies and advance our understanding of insect adaptation to environmental stressors and pest control strategies. Full article

The Colorado potato beetle is a notorious agricultural pest with remarkable adaptability and insecticide resistance. This study conducted comprehensive transcriptome analysis across multiple developmental stages and tissues, focusing on the cytochrome P450 monooxygenase gene family. Using RNA-seq data from 65 datasets, we identified significant transcriptional reprogramming during key developmental transitions, particularly from egg to first instar larva and from third instar larva to adult, reflecting critical biological processes, including feeding initiation and metamorphosis. We identified 3616 tissue-specific genes, with the testis exhibiting the highest transcriptional specialization (1182 genes). Genome-wide screening revealed 78 P450 genes distributed across four major clans with an uneven chromosomal distribution. Expression analysis demonstrated six distinct clusters with tissue and developmental stage-specific patterns. Evolutionary analysis identified five P450 genes under strong positive selection. Analysis of mRNA sequence polymorphisms revealed developmental stage and tissue-dependent patterns, with elevated mutation frequencies in early developmental stages and specific tissues. These distinct tissue and developmental stage-specific mutation patterns in P450 transcripts highlight the dynamic regulation of detoxification genes. Our findings advance the understanding of the molecular mechanisms underlying the beetle’s ecological success and provide valuable targets for developing novel pest management strategies. Full article

Chemosensory systems play a pivotal role in insect survival and reproduction by mediating the detection of volatile organic compounds in the environment. Protaetia brevitarsis (Coleoptera: Scarabaeidae), a phytophagous pest widely distributed across East Asia, poses a significant threat to agro-horticultural systems through crop damage. We conducted antennal transcriptome sequencing of adult beetles and identified 117 chemosensory-related genes, including 66 odorant receptors (ORs), 20 ionotropic receptors, 10 gustatory receptors, 13 odorant-binding proteins (OBPs), four chemosensory proteins, and four sensory neuron membrane proteins. Tissue-specific expression profiling revealed the antennal enrichment of five PbreOBP genes and twenty-three ORs. Notably, sexual dimorphism was observed in OR expression patterns. PbreOR1/6/17/18/21/22/30/32 exhibited male-biased antennal expression, whereas PbreOR25/26/29/38/41/44/61 demonstrated female-biased antennal expression, indicating their potential involvement in sex-specific behaviors, such as pheromone detection and oviposition site selection. A comprehensive description of the antenna chemosensory-related genes of P. brevitarsis has deepened our understanding of the olfactory mechanisms in coleopteran insects. This study also provides a basis for understanding the molecular mechanisms underlying olfaction in P. brevitarsis. Full article