Euplatypus parallelus is an invasive ambrosia beetle causing severe economic damage to rubber plantations across tropical southern China. However, an integrated trapping system combining effective attractants and optimised deployment remains lacking. In a field programme in Danzhou, Hainan, China, we screened seven volatile compounds across eight concentrations in 75
The specialist Helicoverpa assulta and the generalist Helicoverpa armigera are closely related species in Noctuidae. To elucidate the chemical basis underlying their differential oviposition responses to tomato, we compared the oviposition and walking responses of adult females and larvae of both species to tomato volatiles as well as derived synthetic blends. Dichloromethane and hexane extracts of tomato leaves deterred oviposition by H. assulta females. In contrast, all three extracts significantly attracted oviposition by H. armigera females. The components of the dichloromethane extract of tomato leaves were classified according to biosynthetic pathways (acetylmalonate, acetyl‑mevalonate, and shikimate pathways), and four blends were prepared based on their relative percentages in the extract: Blend 1 (green leaf volatiles), Blend 2 (aromatic compounds), Blend 3 (terpenoids), and Blend 4 (the full blend, contained all components that contained in the Blends 1 3). All blends significantly deterred oviposition by H. assulta females, with Blend 4 being the most effective. Only Blends 2 and 3 significantly attracted oviposition by H. armigera females. Larval walking bioassays on a locomotion compensator indicat that the differential host use is attributable to adult oviposition preference, rather than to larval olfactory discrimination between host and non-host volatiles. In field trials, the full blend effectively reduced egg deposition by H. assulta rather than H. armigera on tobacco plants. All together, the oviposition deterrence of H. assulta by tomato appears to be regulated by a “partial blend” of compounds commonly found across the plant kingdom, not by tomato-specific unique components.
Rice is a staple crop that sustains more than half of the global population. However, increasing pressure from insect pests combined with the development of insecticide resistance also poses significant challenges to yield stability and environmental sustainability. Entomopathogenic fungi (EPF) are an alternative biological pest control approach, which are insect pathogens and associate with plants and the rhizosphere. However, studies on EPF in rice are still fragmented, and studies on species diversity, strain-level virulence, endophytism or molecular determinants are rarely integrated across ecological scales. This has prevented the translation of laboratory efficacy to robust field performance and the development of rice-specific, systems-level frameworks. This review synthesizes current information on EPF diversity in rice agroecosystems, their functional ecology in the soil-plant-insect compartments and the molecular mechanisms supporting host infection, plant colonisation and defence modulation. Particular emphasis is given to multitrophic and volatile-mediated interactions, EPF endophytic behaviours and their effects on plant physiology, as well as the roles of fungal secondary metabolites in pest suppression and compatibility within integrated pest management programs. In this instance, establish the conditions under which EPF can reliably provide resilient protection of rice, linking molecular pathways to population and landscape-scale outcomes in flooded paddy environments. The review concludes with the research priorities and technological innovations needed to operationalize EPF-based strategies as central elements of climate-smart, sustainable rice production systems.
The beneficial effects of biostimulants derived from the alga Ascophyllum nodosum have been documented for a wide variety of plant species. However, crops are part of complex agroecosystems, where different trophic levels interact and affect crop development. The present study aimed to assess the potential impact of A. nodosum in a tritrophic system consisting of the faba bean crop (Vicia faba, L.), the herbivore Aphis fabae, and its parasitoid Aphidius matricariae, in a laboratory setup. The experiment, conducted on whole plants in confined cages, included six treatments combining the presence or absence of the algae extract, herbivores, and parasitoids to assess the effects of their interactions. The target effect of the algae extract on plant growth and development was evaluated by measuring plant height, leaf number, leaf area, and dry weight. Possible side effects of the extract were assessed using aphid population development and parasitoid mummy counts and weights. Under the tested conditions, the application of A. nodosum extract did not affect any of the variables used as indicators of V. faba growth and development, i.e. no measurable impact on the plant under normal conditions or in the presence of a biotic stressor. The extract did not influence the population development of the herbivore A. fabae. Furthermore, its application did not impair the aphid-suppression efficacy of A. matricariae, nor did it alter individual mummy weight or, as preliminary observations indicate, mummy abundance. This result suggests that the algae extract and the parasitoid biological control agent evaluated can be used in combination without antagonistic interactions.
Natural vegetation plays an important role in supporting arthropod communities and ecosystem services in olive agroecosystems. However, information on indigenous vegetation and associated arthropods in Tunisian olive groves remains scarce. This study characterized plant and arthropod assemblages in two olive groves to identify key plant species that serve as reservoirs for natural enemies. Vegetation and arthropods were sampled simultaneously from January to June in 2019 and 2021, using quadrat surveys and standardized beating techniques. A total of 22 indigenous plant species belonging to 12 botanical families and 25 arthropod families representing four functional groups were recorded. Full factorial General Linear Models showed that seasonal variation was the main driver of plant diversity, whereas the combined effect of plant species identity and season primarily shaped arthropod and natural enemy assemblages. By contrast, grove identity contributed little to the observed variation. Asteraceae was the dominant plant family and supported the richest natural enemy assemblages. Glebionis coronaria, Senecio gallicus, Anacyclus clavatus, and Diplotaxis erucoides emerged as key reservoir plants, supporting diverse predator and parasitoid assemblages, including Orius sp., Chrysoperla carnea, and Eurytoma spp. These findings highlight the importance of plant species composition in sustaining natural enemy communities and suggest that conserving key natural plant species may strengthen conservation biological control in Mediterranean olive groves.
Wheat is one of the most widely consumed cereal grains globally and plays a critical role in food security. As a staple crop in many households, it provides essential nutrients and contributes significantly to daily caloric intake. Although wheat is attacked by multiple pests, the Russian wheat aphid (RWA), Diuraphis noxia, remains one of the most damaging, causing considerable yield losses. While resistance breeding has long been the preferred control strategy, newly emerging RWA biotypes have increasingly overcome previously effective resistance genes. This highlights the need for alternative approaches, with metabolomics emerging as a valuable tool for identifying metabolic biomarkers that can support faster and more effective resistance breeding. This study, therefore, aimed to investigate the effect of the South African Russian wheat aphid biotype 5 (RWASA5) on the metabolic profiles of two wheat cultivars, Tugela and Tugela DN. The cultivars were infested with RWASA5 and harvested at 0, 4, 8, 24, and 48 h post-infestation, followed by untargeted liquid chromatography–mass spectrometry (LC–MS) profiling. A total of 19 metabolites were identified, of which 12 were upregulated and 7 were downregulated. Phenolic compounds were the dominant class, with secoisolariciresinol diglucoside showing a significant increase in Tugela DN following RWASA5 infestation. Flavonoids formed the most abundant phenolic subgroup. Enriched pathways included glycerophospholipid, linolenic acid, and arachidonic acid metabolism. These findings indicate that RWA infestation triggers distinct metabolic shifts in wheat and provide insights into wheat–RWA interactions for crop improvement.
Ganoderma lucidum filtrates have shown promising agricultural potential due to its capacity to stimulate the production of plant defense metabolites with antimicrobial and insecticidal properties. Here, we evaluated the effects of G. lucidum filtrate application on the antioxidant system of soybean plants and investigated whether soybean defense responses affect the biology and host selection behavior of Spodoptera frugiperda. Different concentrations of filtrate were applied at soybean plants maintained under greenhouse conditions. After 48 h, soybean plants were infested with neonate larvae, which were allowed to develop until the pupal stage. Pupae and adults were maintained under controlled conditions for the evaluation of biological parameters. Feeding and oviposition assays were carried out under choice and no-choice conditions to evaluate host preference behavior. The antioxidant system of soybean responded to the filtrate concentrations, exhibiting variable enzymatic activity from the first through the tenth day after application. Progressive induction of the soybean antioxidant system was detected four days after filtrate application, with SOD, POD, and CAT activities increasing by up to 76.9
Entomopathogenic fungi are increasingly considered for use as biological control agents. However, their effects in tripartite systems involving plants, herbivorous insects, and endophytic fungi remain context dependent and poorly understood. In this study, we tested the hypothesis that inoculation of barley with the entomopathogenic fungus Akanthomyces muscarius affects the biomass of aphids feeding on the plants and influences barley seedling size at early developmental stages. Seedling apical meristems of two barley cultivars, Golden Promise (GP) and Laureate (L), were inoculated with the fungus and subsequently exposed to feeding by the bird cherry-oat aphid Rhopalosiphum padi. Plant dry biomass and total aphid biomass per plant were measured at the end of the experimental period. Inoculation with A. muscarius did not significantly reduce total aphid biomass on either barley cultivar. By contrast, fungal inoculation significantly reduced seedling dry biomass in GP, whereas no such effect was detected in L. Linear mixed-effects modelling revealed significant effects of cultivar, inoculation, and their interaction on plant biomass, indicating cultivar-dependent plant responses to fungal colonisation. Total aphid biomass was significantly affected by cultivar but showed no consistent response to fungal inoculation. This study provides a controlled evaluation of a barley-A. muscarius-aphid tripartite system and highlights cultivar-specific outcomes of fungal inoculation under aphid feeding pressure.
Terpenoids are among the most diverse and abundant classes of plant secondary metabolites, with over 134,000 structures identified to date across green plants. In addition to plants, numerous microorganisms and animals, including arthropods, can synthesise terpenoids. All terpenoids are derived from the 5-carbon isoprene units. These compounds play crucial roles in mediating interactions between plants and arthropods and function as key components of both constitutive and induced defence systems. This review examines the structural diversity of terpenoids—including monoterpenes, sesquiterpenes, diterpenes, triterpenes, and tetraterpenoids —and their multifaceted functions in plant-arthropod relationships. These include plant–herbivore and plant-pollinator interactions, as well as multitrophic interactions between herbivores and carnivores at higher trophic levels, in which plant volatile organic compounds (VOCs) serve as signalling compounds. Terpenoids serve as direct defences through toxicity, deterrence, and growth inhibition of herbivorous arthropods. The volatility and chemical properties of different terpenoid classes influence their ecological roles, with smaller monoterpenes often acting as airborne signals and larger compounds functioning in localised defence. Additionally, some arthropods have evolved mechanisms to sequester, detoxify, or exploit plant terpenoids for their own defence or communication, thereby affecting carnivores through trophic cascades. The essay also explores the evolutionary arms race between plants and arthropods, the genetic and biochemical basis of terpenoid biosynthesis, and the environmental factors influencing terpenoid production and emission. Understanding terpenoid diversity and function has significant implications for pest management strategies, crop protection, and the development of sustainable agricultural practices.
Aphids, as specialised, sap-sucking herbivores, pose a serious threat to plants, both in natural ecosystems and in agriculture. While their specialisation allows effective management, due to their ecological plasticity, any factors disturbing this specialisation may increase their harmfulness. Here we report unexpected exploitation of Capsicum (Magnoliopsida, Solanaceae) by the widely distributed black fern aphid Idiopterus nephrelepidis, previously recorded only on ferns (Polypodiopsida). Incidental observation of unusual host plant exploitation in household conditions demonstrated the remarkable ability of this aphid to alter its nutritional source. Analysis of plant structure demonstrated clear anatomical and chemical differences in both exploited hosts, without specialised structures or sensillary organs in the aphid mouthparts. Two alternative hypotheses explaining the observed host expansion are discussed: (1) In the wild, the black fern aphid exploits (or exploited) some Solanaceae species, possibly as the primary host, consequently retaining an ability to overcome the deterrent properties of pepper. (2) Feeding in an anthropogenic environment (e.g. greenhouse) may reduce the negative selective pressure of natural enemies, enabling aphids to feed on new plant species. In either case, the observed host expansion highlights the need to monitor the potential of this aphid to exploit crop plants.
The whitebacked planthopper (WBPH), Sogatella furcifera (Horváth), is a major phloem-feeding pest of rice, causing significant yield losses across Asia. Exploiting wild rice germplasm offers an opportunity to identify novel resistance mechanisms against this pest. Seven Oryza nivara accessions—CR100318A, CR100327, IR104840, IR105409, IR82980, IR105808, and IR100916—along with the susceptible check TN1 and the resistant check Ptb33, were evaluated for antibiosis resistance capabilities and altered biochemical responses against WBPH during the wet seasons of 2023 and 2024. The study investigated key antibiosis resistance capabilities, including honeydew excretion, nymph emergence, survival, and growth index, alongside the altered activity and concentration of defense-related biochemical constituents such as phenylalanine ammonia lyase (PAL), tyrosine ammonia lyase (TAL), polyphenol oxidase (PPO), total phenols, flavonoids, ortho-dihydroxy phenols, total soluble sugars, reducing sugars, free amino acids, and soluble proteins. Among the tested accessions, IR105409 and CR100318A exhibited significantly lower honeydew excretion by WBPH, which may contribute to reduced phloem nutritional quality, indicating suppressed feeding activity by WBPH. The lowest WBPH nymph emergence was recorded from CR100327 and CR100318A, likely due to elevated PPO activity and reduced amino acid content. Furthermore, IR105409 showed reduced WBPH nymph survival and prolonged nymphal development, which were associated with elevated PAL and TAL activities in the accession, suggesting a strong biochemical basis for WBPH resistance.
Ambrosia beetles play a dual ecological role in forests. Most species act as decomposers, and cause fast wood breakdown and nutrient cycling. A smaller group is invasive and attacks living trees, causing major damage to forests, orchards, and timber resources. These beetles exhibit symbiotic fungal relationships and diverse social behaviors ranging from cooperative breeding to eusociality, often called “insect socialism”. Key traits (labor division, brood care, and overlapping generations) enhance colonization success, stress tolerance, and host exploitation. As a result, they influence gallery success, community structure, pathogen dynamics, predator interactions, and forest invasions. This review focuses sociality in ambrosia beetles as cooperative behaviors that support gallery construction, fungal cultivation, and defense. Moreover, it examines roles in nutrient cycling and decomposition. Likewise, it shows how sociality boosts reproduction and resource sharing. Furthermore, social structures drive colonization, invasion, damage, symbiosis, defense, biodiversity shifts, and adaptation amid insecticide resistance. Finally, it evaluates management challenges and innovations such as pheromone disruption and gallery interference. Besides, it urges integrating microbial dynamics with social behavior research to fill genomic gaps in fungicide resistance, and outbreak models for interdisciplinary management. Likewise, insect ecology reflects habitat filtering, trophic interactions, and rapid adaptation. Furthermore, tropical field studies capture community turnover, seasonal dynamics, and species interactions that are often missed by laboratory work alone. Genomic comparisons reveal conserved eusocial signatures, including regulatory complexity, altered communication, and gene changes. However, gaps remain in understudied tropical groups due to limited expertise, uneven sampling, and weak resources. Thus, future research should integrate long-term field monitoring with expanded genomics to test hypotheses on social evolution, resilience, and biodiversity loss.
The interactions between moths and lichens are diverse and have long fascinated ecologists and evolutionary biologists. Lichens play multiple roles in these associations, serving as a food source, shelter, a substrate for concealment, and a background that may facilitate camouflage or deceptive resemblance. Background matching with lichens is a well-known anti-predator strategy in Lepidoptera, where wing patterns often imitate lichen textures. However, most documented cases involve other lichens, whereas umbilicate lichens such as Lasallia have previously not been reported as models. Here, we present the first record of a moth exhibiting lichen-associated camouflage with Lasallia pertusa (Rass.) Llano, documented from Duggi locality, Chamba District, Himachal Pradesh, India. The moth’s forewing pattern, characterized by pustule-like markings and pale interspaces closely resembles the mottled thallus of L. pertusa, providing effective concealment on exposed rock surfaces. The present report contributes to the understanding of lichen-based crypsis and emphasizes the ecological significance of lichens in shaping predator–prey interactions in montane ecosystems.
Coccinellids are generalist predators and play a crucial role in the biological control of aphids. During periods of low availability of their primary prey, these insects can supplement their diet with alternative resources, such as pollen, which is a rich source of proteins, carbohydrates, and essential amino acids. However, the consumption of alternative resources may vary among habitats, potentially supporting coccinellid persistence in the landscape when aphids are scarce. This study analyzed the frequency and abundance of pollen consumption in eight coccinellid species collected during the summer in six land-cover types (i.e. habitats) representative of the agricultural landscape in Central Chile: alfalfa, maize, vineyards, tree hedgerows, sclerophyllous shrubland, and abandoned sites. In total, 336 individuals were collected and dissected to examine their intestines for pollen. Pollen grains from nine plant families were identified in the guts of coccinellids. Both coccinellid species and habitat significantly influenced the frequency and abundance of pollen in the intestines. All species exhibited a pollen consumption frequency above 50
Assessment of pollinator community, foraging behavior and pollination efficiency is essential for improving sunflower yield and optimizing crop and pollinator management. The experiment was carried out in a farmer’s field located at Bhayna village, West Bengal, India to study the pollinator community and its role in sunflower pollination. Field trials were conducted to study the abundance and diversity of pollinators. The foraging pattern was recorded at 08:00, 10:00, 12:00, 14:00, 16:00, and 18:00 h. The pollination efficiency index, a composite measure of pollinator abundance, visitation rate, flower handling time, and pollen load was assessed to understand the pollination effectiveness of individual bee pollinators. The effects of hand pollination, open pollination, combined hand and open pollination, and pollinator exclusion on sunflower yield were also assessed. Results showed that, among the insect pollinators, Apis dorsata was most abundant (27.46
Honeydew is a sugar-rich sticky liquid excreted by aphids and other hemipterous insects, such as scale insects, whiteflies, and psyllids, that feed on plant phloem sap. Compared to flower nectar, aphid honeydew contains the same primary sugars (sucrose, glucose, and fructose) as nectar, but also additional oligosaccharides, such as melezitose and erlose, which are synthesised by aphids. Honeydew deposited on leaf surfaces, other surfaces, and in soil plays various roles in the ecosystem, serving as an essential food source for ants, bees, and bumblebees, as well as a supplementary food source for many other animal groups. Bees and ants are important predators and pollinators, particularly in forest ecosystems. Consequently, honeydew produced by aphids and other sap-feeding insects plays a crucial role in maintaining ecosystem functioning. A direct ecosystem service provided by aphid honeydew is a particular honeydew honey, but a substantial part of uni- and multiflower honey may also contain honeydew. Other ecosystem services include enhanced soil microbial activity and reduced nitrogen leaching from forest soil. In urban environments, the honeydew of arboreal aphids can be a significant nuisance, as it coats walls, cars and playgrounds with a sticky layer that collects dust and pollen and supports the growth of sooty mould. Sooty mould growing on honeydew on the leaf surfaces of understory plants can reduce photosynthesis and plant growth. We conclude that extensive multi-trophic network mappings are needed to better quantify how honeydew links above-ground and below-ground food webs, particularly nutrient transfer pathways and cascading effects.
Plant resistance to insect herbivores depends chiefly on the activation of biochemical mechanisms. Present study demonstrated that fall armyworm (FAW) feeding, exogenous application of MeJA, and wounding followed by regurgitant application induced metabolites and defensive enzymes in seven maize genotypes. The findings revealed that the resistant and moderately resistant genotypes significantly induced higher ferulic and p-coumaric acid levels in response to FAW feeding and wounding, followed by regurgitation treatments. The amino acid profile revealed genotype-specific responses, in which MIL9-1260 (MR) exhibited the highest accumulation of essential amino acids, namely valine, methionine, phenylalanine, leucine, lysine, threonine, isoleucine, and non-essential amino acids like alanine, aspartic acid, glutamic acid, serine, and tyrosine with MeJA treatment. However, in the susceptible genotype Sarhad HSRB, the levels of essential and non-essential amino acids decreased after treatment induction. The present study indicates that maize phenolic defense responses were highly induced by FAW attack while amino acid levels and enzymatic (POX and SOD) activities triggered with MeJA in most of the resistant and moderately resistant genotypes. Furthermore, the genotypes MIL 9–1308 and MIL 9–1309 were identified as best sources of resistance and could be utilized in the breeding program to develop FAW-resistant maize hybrids.
Vanilla planifolia (Orchidaceae), commonly known as vanilla, is the only orchid species cultivated commercially for its edible pods and is one of the most economically important spices worldwide. In northeastern Brazil, populations of Montella sp. (Coleoptera: Curculionidae) have emerged as a significant pest of vanilla crops, with both larvae and adults causing damage. Notably, adults are frequently observed on the flowers, suggesting a potential role of floral volatile organic compounds (VOCs) in host localization. To investigate this, we analysed the floral VOC profile of V. planifolia using dynamic headspace collection followed by gas chromatography-mass spectrometry (GC-MS). Six compounds were identified: beta-myrcene, (R)-limonene, (Z)-beta-ocimene, eucalyptol, (E)-beta-ocimene, and beta-caryophyllene, with (E)-beta-ocimene being the predominant component of the natural floral bouquet. In Y-tube olfactometer assays, Montella sp. adults were significantly attracted to fresh flowers, floral VOC extracts, and a beta-ocimene isomer mixture (Z/E = 1:3), the latter eliciting responses comparable to the full floral extract. These findings indicate that beta-ocimene contributes to the attraction of Montella sp. and may be involved in host location, with the (E)-isomer representing the predominant form in the natural floral blend. Behaviourally active floral VOCs may therefore be exploited as semiochemical-based tools to improve monitoring and support integrated pest management strategies in vanilla cultivation systems.
Wireworms (Coleoptera: Elateridae), larvae of click beetles, form a complex of significant subterranean pests damaging important crops such as potatoes and corn, with Agriotes obscurus being prevalent in Switzerland. Buckwheat acts as a biofumigant and affect wireworms, reducing their feeding and their juvenile growth. This study aimed to evaluate the effects of common buckwheat (Fagopyrum esculentum) on the development of A. obscurus larvae, comparing four buckwheat varieties (Grauer Heiden, Val Pusteria, Kitawasesoba, Drushina) against a barley control. Larvae were subjected to no-choice feeding tests under controlled conditions, with measurements of weight, length, and head capsule width taken over 12 weeks. Behavioral responses to different buckwheat varieties were assessed via double-choice olfactometry to examine attraction and preference. Results indicated no significant differences in weight or head capsule width between treatments, though barley-fed larvae showed a slight growth advantage. However, larval length exhibited significant varietal differences, with certain buckwheat varieties inhibiting growth more markedly. Mortality rates were unaffected, likely due to the advanced larval stage tested. Olfactometry revealed no clear preference towards any buckwheat variety, suggesting volatile profiles do not strongly influence larval attraction. These findings suggest that while buckwheat can impair wireworm development, especially larval length, variation among buckwheat varieties offers potential for optimizing integrated pest management strategies. The observed lack of behavioural attraction differences may suggest an incorporation of buckwheat as a cover crop, may disrupt wireworm life cycles and suppress damage sustainably.
Notwithstanding the ecological significance of Meliponini as keystone pollinators in tropical ecosystems, their diversity and interactions with plants remain under-documented due to taxonomic impediments and sampling constraints of the Amazon Basin. By applying an integrative taxonomic approach, 251 stingless bees collected across 7 Peruvian Departments were assigned to 16 genera—with Trigona, Melipona, Nannotrigona, and Tetragonisca as the most prevalent—yielding 66 pollen types from 33 botanical families. To elucidate foraging patterns, body-adhered pollen was identified after extraction using an optimized, non-destructive, sonication technique. While most of the identified botanical families (e.g., Arecaceae, Myrtaceae, Melastomataceae) are consistent with established records of stingless bee-floral interaction in Central/South America, others—including Adoxaceae, Cistaceae, and Theaceae—constitute novel report for this geographic region. Notably, our findings highlighted the role of stingless bees in visiting flora of high economic and ecological importance, such as Camellia sinensis (tea tree), Ipomoea batatas (sweet potato), Croton lechleri (“sangre de grado”), and the flood-forest palm Socratea exorrhiza. Overall these findings underscore the importance of palynological analyses conducted on pollen collected by Meliponini to better characterise the otherwise inaccessible botanical diversity of Amazonia. We also note the need of addressing the knowledge gap in Meliponini taxonomy and biodiversity to better protect the vital ecosystem services they provide in both natural and agroecosystems.
