Search Results (789)

The sorghum aphid (Melanaphis sorghi), a phloem-feeding insect pest, causes severe economic losses in sorghum-producing regions worldwide. During feeding, aphids secrete salivary proteins with potential effector functions that play pivotal roles in plant–insect interactions. However, relatively few secreted proteins and effectors have been characterized in M. sorghi. In this study, proteomic analysis of aphid-infested sorghum leaves identified 69 putative aphid-derived proteins. Bioinformatic analyses were subsequently used to predict signal peptides within these proteins. Among the five candidates with signal peptides, MsSP1 was further confirmed to be delivered into sorghum tissues during aphid feeding by immunoblotting using a specific anti-MsSP1 antibody. Functional characterization revealed that silencing the MsSP1 gene in aphids by RNAi interference significantly reduced aphid fitness on sorghum. Moreover, transient expression of MsSP1 in Nicotiana benthamiana suppressed cryptogein-induced cell death and hydrogen peroxide accumulation, indicating that MsSP1 interferes with plant immune responses. Collectively, these results suggest that MsSP1 may act as a virulence effector that enhances aphid performance while suppressing host defense. This study expands current knowledge of plant–aphid interactions and provides new insights that may facilitate the development of sustainable pest-management strategies. Full article

Insect–microbe symbioses play pivotal roles in host ecology and plant–insect interactions, yet their species-specific functions in agricultural pests remain less understood. This study elucidates the functional role of symbiotic microbial communities in mediating insect host fitness and plant defense responses in two economically important whitefly species, Bemisia tabaci Gennadius and Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae). Using integrated molecular and physiological approaches, we characterized species-specific responses to antibiotic treatments (rifampicin and tetracycline) and their cascading effects on tripartite plant–insect–microbe interactions. In B. tabaci, antibiotic exposure induced significant depletion of the obligate symbiont Portiera and facultative Rickettsia (except for tetracycline-mediated Portiera proliferation), correlating with enhanced plant immune responses. In parallel, antibiotic treatments increased the titers of Hamiltonella and Rickettsia alongside constitutive plant defense suppression in T. vaporariorum, though tetracycline uniquely induced AOS expression elevation. Developmental assays revealed stage-specific vulnerabilities, with late nymphal and pupal stages showing high sensitivity to symbiont disruption, culminating in complete mortality within 40–50 d post-treatment. These findings show that microbial symbionts are essential to whitefly nutrition and evasion of plant anti-herbivore defenses. Our results provide a mechanistic basis for understanding symbiont-assisted invasion success in these whitefly species and underscore the potential of microbiome-targeted approaches for sustainable whitefly management. Full article

The transition from simple herbivory to specialised gall induction in Cynipidae marks an evolutionary peak in insect–plant interactions. This structural and ultrastructural study suggests that the gall wasp larva has evolved from a passive consumer into a biological architect, utilising a highly specialised body plan. The structure of the large midgut, the midgut epithelium reinforced by septate junctions, and the cuboidal cells of the hindgut allow for the possibility that the larva of Andricus quercustozae may control itself independently from its host, working as an active producer rather than just recycling materials. The foregut constitutes approximately 10% of the alimentary canal length, while the large blind midgut occupies 80%. The remaining 10% consists of a specialised hindgut tube, which is anteriorly closed and contains a reinforced, cuticularised external anal pore. This posterior structure, together with a dense aggregation of urocytes and oenocytes in the anal region, presumed systemic homeostasis and the symmetrical distribution of hormonal signals. These anatomical hallmarks provide a structural baseline to hypothesize that biosynthesis may represent a key mechanism for phytohormone acquisition, while suggesting that this closed-circuit anatomy could potentially be a contributing factor influencing the spherical morphogenesis of the gall. Full article

Dittrichia viscosa (L.) Greuter is a Mediterranean species widely recognized for its remarkable ecological plasticity and its rich repertoire of secondary metabolites, among which volatile organic compounds (VOCs) play a central role. This review provides an integrative synthesis of current knowledge on D. viscosa, with a primary focus on its VOCs, including their extraction techniques, chemotypic variability, and biological activities, while contextualizing these compounds within the species’ broader phytochemical and ecological framework. Available evidence indicates that VOC profiles are dominated by terpenoids, particularly oxygenated sesquiterpenes and monoterpenes. The composition of volatile fractions is strongly influenced by extraction methodology, plant organ, developmental stage, and geographic origin, resulting in pronounced chemotypic variability across Mediterranean populations. Beyond their direct bioactivity, VOCs are considered in their ecological context, particularly in relation to glandular trichome-mediated secretion, plant–insect interactions, and potential applications in integrated pest management. Non-volatile metabolites are also discussed to provide a comprehensive view of the species’ bioactive potential. Overall, D. viscosa emerges as a multifunctional species in which VOCs are a pivotal, though not isolated, component of a complex phytochemical system with promising applications in agriculture, pharmacology, and environmental management. While the convergence of multiple studies supports the biological potential of D. viscosa and its metabolites, particularly in vitro, the translation of these findings into in vivo efficacy and safety remains an important area for future research. This integrative perspective highlights the need for standardized analytical approaches and chemotype-aware studies to fully exploit the biological and biotechnological potential of this Mediterranean species. Full article

Anoplophora glabripennis (ALB) is an invasive wood-boring cerambycid that causes extensive damage to hardwood host trees through sequential tissue penetration from the bark to the sapwood. Developmental biology of ALB is well established. However, interactions among its life cycle, environmental contaminants, and fungal associates remain poorly understood. In particular, the ecological relationships among microplastics, entomopathogenic fungi, and the fungal symbiont Fusarium solani (FSSC) within ALB-associated woody tissues remain largely uncharacterized. This review develops a conceptual anatomical framework integrating ALB developmental biology, fungal associations, frass deposition pathways, and potential microplastic interactions within woody host tissues. The framework was constructed through ecological literature synthesis and anatomical reconstruction. To our knowledge, this represents the first conceptual framework integrating ALB developmental anatomy, fungal symbiosis, and potential microplastic interactions within host tree gallery systems. A longitudinal cross-sectional model was developed to illustrate oviposition, larval gallery formation, pupation, and adult emergence in relation to the outer bark, cambium/phloem, sapwood, and heartwood. FSSC isolates previously documented on ALB egg surfaces following oviposition and within ALB frass were examined, thereby positioning the fungal symbiont both within and outside galleries produced by ALB throughout its life cycle. Previous studies have demonstrated that microplastics can be taken up by plant stem tissues and accumulate on the forest floor through atmospheric deposition. This widespread presence suggests that micro- and nanoplastics may penetrate sapwood and heartwood galleries through xylem and phloem flow. These transport pathways may overlap with regions where late-instar larvae actively forage. The integrative framework presented here highlights potential ecological interactions within the gallery microhabitat and provides a foundation for future experimental investigations into contaminant–pathogen–host dynamics in xylophagous insects. While we refrain from proposing specific management strategies, we present a conceptual framework to elucidate how microplastics may serve as incidental contact points for cerambycid anatomy and fungal propagules. We hypothesize that these interactions link microplastic pollution to invertebrate ecology. Microplastics may function as substrates for fungal spores within forest canopies and gallery systems, potentially influencing fungal persistence, contaminant transport, and ecological dynamics within infested forest habitats. Full article

Entomopathogenic fungi (EPF) are well established as biological control agents, but their emerging role as endophytes reveals a broader and more powerful function in crop protection. By colonizing plant tissues, endophytic entomopathogenic fungi (EEPF) create a dynamic tripartite interaction between plants, fungi, and herbivores, enabling systemic, plant-mediated pest suppression. This review synthesizes current knowledge on the behavioral and ecological responses of herbivorous arthropods to EEPF-colonized plants, with an emphasis on the mechanisms and implications for integrated pest management (IPM). Growing evidence indicates that EEPF consistently modify herbivore behavior and performance across diverse crops and insect taxa. Colonization frequently alters feeding, host selection, and oviposition, often deterring pests, although mediated responses may vary among fungal species, host plants, insect taxa, and environmental conditions. These responses are driven by EEPF-induced changes in plant chemistry, including shifts in volatile organic compounds (VOCs) and defensive metabolites. In parallel, EEPF impair insect fitness by delaying development, reducing survival, and lowering fecundity, thereby suppressing pest populations. These plant-mediated and behavioral changes extend to multitrophic interactions, potentially affecting associations with natural enemies and the transmission efficiency of some insect vectors of plant viruses. Despite rapid progress, critical gaps remain in resolving the mechanistic basis of these interactions and their stability under field conditions. Advancing the application of EEPF will require integrated approaches combining microbial ecology, chemical ecology, and insect behavioral biology. Harnessing these interactions offers a compelling pathway to reduce reliance on synthetic pesticides while enhancing the resilience and sustainability of agricultural systems. Full article

Helicoverpa armigera is one of the most destructive polyphagous pests, yet the transcriptional organization underlying its digestive capacity remains poorly resolved. Here, we compiled 579 publicly available RNA-seq libraries representing 54 independent experiments and quantified transcript abundance across tissues and developmental stages. This complete dataset was used to support broader tissue-level expression profiling. After metadata harmonization and quality filtering, a subset of 130 biologically comparable libraries from five tissue/developmental categories was retained for weighted gene co-expression network analysis. WGCNA identified four biologically informative modules, among which the turquoise module was positively associated with fourth- and fifth-instar larval midgut samples. Independent expression profiling revealed strong midgut-biased expression of several trypsin- and chymotrypsin-like serine proteases, although only a subset of these genes was assigned to the turquoise module. Descriptive functional annotation of this module identified 202 co-expressed loci, including digestive enzymes, nutrient transporters, detoxification-related proteins, epithelial components and putative transcriptional or signaling-associated genes. Phylogenetic analyses and manual inspection of genomic locations further showed that several digestive protease genes occur in local clusters and have closely related counterparts in H. zea, suggesting partial conservation of local genomic organization. Collectively, these results describe a midgut-associated co-expression module containing genes associated with digestive, absorptive and protective functions and provide candidate genes for future functional studies. Full article

Mangrove forests along China’s coastline serve as vital ecological barriers and blue carbon reservoirs. However, pests and diseases have become the primary biotic threats driving stand decline and diminished carbon sequestration capacity. This review synthesizes current knowledge on the major insect pests and plant diseases affecting Chinese coastal mangroves, focusing on their species profiles, characteristic damage symptoms, occurrence dynamics, and integrated control strategies. Fungal pathogens predominate among the diseases, with outbreaks most common during periods of high temperatures and humidity or low temperatures combined with high humidity; these often interact synergistically with insect pests. The dominant insect pests comprise leaf-feeding Lepidoptera, sap-sucking Hemiptera, and wood-boring Coleoptera, which spread through diverse pathways and can rapidly produce extensive “scorched” damage across mangrove stands during epidemic events. Control efforts follow the principle of “prevention first and integrated management,” incorporating cultural practices, chemical interventions, biological control agents, physical trapping methods, and rigorous quarantine-monitoring protocols. When applied in concert, these measures effectively limit damage to acceptably low levels. Recent studies identify pest–disease interactions and climate change as the foremost challenges in current management. Future priorities should include advancing molecular identification techniques, breeding disease-resistant varieties, and developing environmentally friendly biopesticides to establish precision ecological control systems. Such advances will deliver robust scientific support for mangrove conservation and the achievement of China’s dual-carbon goals. Full article

Toxoptera aurantii is a globally distributed piercing-sucking pest that severely threatens tea production. While the direct damage caused by aphid feeding is well documented, the systemic effects of infestation on plant-associated and soil microbial communities remain poorly understood. Here, we employed full-length 16S rRNA gene sequencing and untargeted metabolomics to investigate the influence of T. aurantii infestation on the microbiota of tea plants (Camellia sinensis) and rhizosphere soil across four sample compartments: aphid bodies, healthy leaves, aphid-infested leaves, and root-zone soil. Our results revealed pronounced niche-specific microbial assembly patterns. The aphid microbiome exhibited the lowest diversity and was dominated by obligate endosymbionts, including Buchnera aphidicola and the secondary symbiont Serratia symbiotica. Soil harbored the highest microbial diversity with a balanced phylum-level structure. Aphid infestation significantly reduced phyllosphere microbial diversity (Shannon index) and shifted community composition, with a decline in a sequence putatively assigned to Methylobacterium brachiatum and a modest increase in a taxon assigned to the opportunistic plant pathogen OTU assigned to Dickeya chrysanthemi. This pattern suggests a hypothesis that aphid infestation may create conditions permissive for such opportunistic pathogens, although experimental validation is required. Concurrently, infestation was associated with profound metabolic reprograming in tea leaves, including upregulation of defense-related flavonoids and terpenoids and downregulation of several primary metabolites. Notably, the phyllosphere of infested leaves showed reduced microbial diversity and an increased relative abundance of a 16S rRNA sequence assigned to Dickeya chrysanthemi, while certain plant-derived antimicrobial metabolites were decreased. These patterns suggest a possible association between aphid infestation, altered antimicrobial metabolite profiles and increased relative abundance of Dickeya-assigned sequences. These findings demonstrate that T. aurantii infestation triggers a systemic response in the aboveground compartments (aphid and leaf), while the soil compartment maintains a distinct and highly diverse microbial community that serves as a potential reservoir. The study characterizes microbial communities across these three compartments without inferring infestation-driven soil remodeling. This study advances our understanding of tripartite interactions in tea ecosystems and provides a basis for developing microbiome-based strategies for sustainable pest management. Full article

Silene zawadskii Herbich is an endemic species restricted to the South-Eastern Carpathians, being found in Romania and Ukraine. The species is rare and protected in the two countries. The root system is deep, to facilitate water absorption, the basal leaves, arranged in a rosette, are leathery and glabrous. The stem presents numerous multicellular, uniseriate non-glandular trichomes, only in the upper part; they become caducous at the base. The small size of the plant, correlated with the very narrow xylem vessels, represents a way of increasing the resistance to physiological drought and preventing embolism in drier periods. Another particular feature of this species is the presence of numerous large calcium oxalate crystals (druses), both in the stem and especially in the leaves. The flowers are adapted to entomophilous pollination, showing structural traits that facilitate interactions with alpine pollinators, particularly under conditions of reduced insect diversity at high altitudes. These anatomical traits reflect its ecological specialization, making it a valuable indicator for assessing edaphic–climatic niche specificity and the functional connectivity of high-altitude ecological networks. Full article

Lychee, an entomophilous fruit crop cultivated in tropical and subtropical regions, depends heavily on pollination services for optimal fruit yield and the economic sustainability of farmers. However, information on its pollinator interactions remains limited. This study was conducted over three flowering seasons to document the pollinator assemblage of lychee and examine variation in their activity under different physical conditions, including time of day, panicle height, and light–shade environments. Several insects (here, 47, including many butterflies, bees and flies) were recorded as flower visitors of lychee. The most effective pollinators were Apis cerana, Apis dorsata, Apis florea, Braunsapis mixta, and Tetragonula pagdeni. Pollinator abundance, species richness, diversity, and foraging traits (e.g., flower visitation rate and flower handling time) varied with daytime, inflorescence height, and light availability (light versus shade). Greater abundance, richness, and diversity were documented between 8:00 and 12:00 h, at mid-canopy height (2–6 m), and on well-lit inflorescences. Flower visitation rate was higher under these conditions, whereas flower handling time was lower. This study uncovered the key pollinators of lychee and demonstrated that plant–pollinator interactions vary across different physical conditions. These findings may help to improve pollinator management and enhance pollination services in lychee cultivation. Full article

Artemisia campestris is a medicinal plant species endemic to Algeria, particularly abundant in the southern regions and the central Sahara. Its long-standing use in traditional medicine has recently gained scientific attention, prompting further investigation into its bioactive potential. This study focuses on the phytochemical composition and biological activity of its hydromethanolic extract, with a particular emphasis on its ability to inhibit neural enzymes associated with insect physiology with particular relevance to Aphis gossypii (Glover), a major polyphagous agricultural pest. Preliminary screening revealed a diverse array of secondary metabolites, including tannins (catechic and gallic), flavonoids, quinones, glycosides, terpenoids, saponins, coumarins, and alkaloids; however, anthocyanins were not detected. Quantitative analysis confirmed high concentrations of total phenolics (80.91 ± 1.58 mg GAE/g), flavonoids (60.45 ± 2.02 mg RE/g), phenolic acids (4.24 ± 0.38 mg CAE/g), and condensed tannins (2.26 ± 0.29 mg CE/g). Enzyme inhibition assays were performed using Ellman’s method, and IC₅₀ values were calculated by nonlinear regression analysis based on dose–response curves. The extract demonstrated significant in vitro inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), with IC₅₀ values of 13.79 ± 0.79 µg/mL and 8.34 ± 0.58 µg/mL, respectively. Molecular docking analyses further confirmed strong binding affinities of cyanidin-3-O-glucoside, malvidin-3-O-glucoside, and apigenin (−8.20 to −8.50 kcal/mol) with the AChE active site, stabilized by hydrogen bonding and π–π interactions with key residues. These results were benchmarked against galantamine, a reference inhibitor, which exhibited IC₅₀ values of 1.50 ± 0.12 µg/mL under the same conditions. Although galantamine showed superior potency, the relatively low IC₅₀ values of the A. campestris extract support its potential as a natural cholinesterase-inhibitory agent warranting further investigation. These findings suggest that A. campestris may represent a promising source of natural cholinesterase inhibitors with potential relevance for eco-friendly insect control. These in vitro and in silico findings provide a mechanistic rationale warranting future in vivo bioassay validation against A. gossypii and related agricultural pests. Full article

The increasing resistance of agricultural pests and disease-vectoring arthropods to synthetic pesticides underscores the urgent need for novel and sustainable biocidal agents. This study evaluates, for the first time, the insect antifeedant and ixodicidal activities of essential oils derived from ten Amazonian Piper species and their major constituents. Antifeedant effects were assessed against Spodoptera littoralis, Myzus persicae, and Rhopalosiphum padi, whereas ixodicidal activity was tested on Hyalomma lusitanicum. Additionally, the effects of these oils on the plant-parasitic nematode Meloidogyne javanica were investigated. Essential oils from Piper mituense (51.6% apiol) and P. sancti-felicis (76.1% apiol) exhibited the highest bioactivity, achieving more than 75% feeding inhibition across all insect species and 100% tick mortality. P. mituense consistently demonstrated greater potency, suggesting possible synergistic interactions among its minor constituents. Principal component analysis linked apiol-rich chemotypes with broad-spectrum activity. In contrast, oils rich in oxygenated caryophyllene derivatives, particularly those from P. casapiense, showed strong selective antifeedant effects against R. padi. Pure apiol displayed activity across all assays, whereas no nematicidal effects were observed. Molecular docking analyses supported these findings, indicating that apiol can interact with acetylcholinesterase in addition to its known effect on cytochrome P450 targets. Overall, these results identify complementary Piper chemotypes with promising potential as dual-purpose biopesticides for integrated pest management strategies. Full article

Globally, Trichogramma Westwood (Hymenoptera: Trichogrammatidae) is known as the most effective biological control agent due to its ability to parasitize insect pest eggs. However, identifying an appropriate host is vital for Trichogramma to prosper. Therefore, this study delves into the complex role of semiochemicals in shaping the host-seeking behavior of Trichogramma parasitoids, with a particular focus on their responses to both plant-derived and host-derived cues. The mechanism of semiochemical reception in Trichogramma wasps relies on a highly specialized, sensitive olfactory and gustatory system to locate host eggs and mates. Semiochemicals, which mediate ecological interactions, have been identified as pivotal in influencing the parasitic efficiency of Trichogramma species. Trichogramma’s host-seeking behavior is influenced not solely by ovipositional cues but also by the intrinsic physical attributes of Lepidopteran hosts, such as the scales on the wings and abdomen, which emit semiochemicals capable of eliciting positive chemotactic responses, thereby guiding parasitoids toward optimal sites for oviposition. Furthermore, the interplay between insect-derived and plant-derived chemical cues exhibits a synergistic effect, collectively enhancing the chemotactic attraction of Trichogramma, thereby fine-tuning its host-seeking behavior with greater precision and specificity. This study further underscores Trichogramma’s innate behavioral ability to discriminate between host eggs of varying developmental stages, facilitating the precise identification and selection of the most suitable host for parasitization. Age and experience both make Trichogramma more selective of hosts, but younger parasitoids may take a broader approach to host selection due to their greater life expectancy. Furthermore, the removal of these cues affects their host localization and learning abilities. Associative learning enables Trichogramma to exhibit flexible behaviors, providing them with a selective advantage; allows them to explore various hosts; and reduces environmental uncertainty. Plant structure, host density, and host age are the key factors that significantly influence the foraging and parasitism of Trichogramma. The searching speed of this parasitoid is significantly influenced by temperature. Heat stress increases VOC emissions in plants such as potato via stomatal opening, reducing herbivore attraction and enhancing parasitoid recruitment. Furthermore, air pollution, including CO₂, O₃, and NOx, impairs parasitoid efficiency by disrupting volatile-mediated host location and reducing biological control performance. Trichogramma wasps are generally effective biological control agents, but their success depends on the species used, target pest, crop, release density, and field conditions. Overall, species such as T. ostriniae, T. japonicum, and T. leucaniae show the strongest performance in several crops by increasing parasitism, reducing pest damage, and improving yield. This study highlights the successful integration of semiochemical cues in pest management programs and the effective utilization of Trichogramma in conjunction with entomopathogenic bacteria to control Lepidopteran pests. This approach contributes to the development of more effective pest management strategies, thereby promoting agricultural sustainability. Full article

Plants can provide natural enemies with alternative food resources that enhance their performance in addition to prey consumption. Extrafloral nectaries attract beneficial insects by supplying nectar in exchange for pest suppression, although other arthropods may also benefit. This study aimed to characterize the extrafloral nectar composition of bottle gourd, Lagenaria siceraria (Molina) Standley (Cucurbitaceae), a host plant of Nesidiocoris tenuis Reuter (Hemiptera: Miridae), and to evaluate the effects of its carbohydrate profile on key biological parameters of this predator. Extrafloral nectar was chemically characterized for carbohydrate and amino acid composition, and laboratory bioassays were conducted to assess the effects of a sugar solution of the extrafloral nectar carbohydrate profile when provided with two factitious food sources, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs and Artemia sp. (Anostraca: Artemiidae) cysts. Female egg production, nymphal development and food source consumption were evaluated. Chemical analysis revealed that bottle gourd extrafloral nectar consisted primarily of glucose, fructose, sucrose and melezitose, while serine was the dominant amino acid. Four essential amino acids were also detected. Sugar supplementation did not affect nymphal development rate but significantly reduced factitious food consumption. Significant differences in egg production were observed among feeding regimes. Sugar supplementation did not affect egg production when E. kuehniella eggs were provided, but significantly increased egg production when Artemia cysts were used as food source. These results indicate that extrafloral nectar carbohydrates can function as effective supplementary nutritional resources for N. tenuis, particularly when lower-quality factitious food sources are used. These findings enhance our understanding of plant–predator nutritional interactions and suggest that extrafloral nectar-derived components warrant further evaluation for incorporation into mass rearing protocols. Full article