Arthropod-Plant Interactions最新文献

Ants and plants often establish mutualisms. However, not all plants offer direct rewards, which can favor ant access to flowers. These interactions can have antagonistic aspects, especially for flower visitors. But do they also affect flower-living herbivores? In this study, we evaluated the interaction between the ant Camponotus termitarius (Emery, 1902) and Eryngium chamissonis Urb., a plant that lacks a distraction mechanism to keep ants away from flowers. Specifically, we investigated whether the presence of ants affects the abundance of flower thrips, and whether the density of these insects varies with the number of ants present. Through field experiments, we collected inflorescences exposed to and deprived of ant visitation for 24 h and counted the abundance of associated thrips. Our analyses reveal that the presence of ants differentially influences the developmental stages of flower thrips. These effects were adverse for the abundance of larvae thrips, while we observed the opposite for adults. These results demonstrate that the presence of ants decreased the presence of floral herbivores at developmental stages that require larger food sources for E. chamissonis. Thus, the lack of adaptations to prevent ant visitation to the flowers of this plant might lead to a reduction in the presence of flower-living herbivores.

The diamondback moth, Plutella xylostella, has developed strategies to overcome the challenging waxy surfaces of plants. Females can lay their eggs on pruinose Brassicaceae plants using a secretion from their colleterial glands, which acts as an egg adhesive. The present microscopic analyses, along with contact angle and force measurements, show that this secretion wets hydrophilic glass surfaces significantly better than hydrophobic ones, forming superthin layers with limited volume. Consequently, the pull-off forces required to remove the eggs are significantly greater on hydrophilic glass (23 mN) compared to hydrophobic glass (2 mN), indicating adhesive strengths of 198 and 29 kPa, respectively. The safety factors, which indicate how many times the weight of the egg (23 µg) corresponds to the pull-off force, are remarkably high: 101,689 for hydrophilic surfaces and 8517 for hydrophobic ones. Egg adhesion to plants varies depending on plant surface structures. Pull-off forces significantly decrease with the increasing number of plant epicuticular wax crystals. For example, safety factors measure 1795 on young adaxial white cabbage leaves and reach as high as 25,461 on the petioles of older Chinese cabbage leaves. This attachment ability is facilitated by the predominantly protein and lipid composition of the egg adhesive, alongside the structural matrices created by plant wax crystals and trichomes embedded within the adhesive. Raman spectroscopy of the untreated solidified egg adhesive reveals characteristic amide I and III bands, a β-sheet structural motif, and the presence of aromatic amino acids phenylalanine and tyrosine, as well as saturated fatty acids. Based on a comprehensive discussion with previous findings, we propose that there is a trade-off between secure egg adhesion and the selection of oviposition sites that match the offspring’s preferences and provide enemy-free spaces. Understanding P. xylostella’s egg adhesion mechanisms and the characteristics of the adhesive substance may contribute to the improvement of pest control strategies, including physical measures, and the advancement of bioinspired adhesives. Moreover, our study should stimulate future integrative and multidisciplinary research on insect egg adhesives, promoting a comprehensive understanding from various perspectives.

Semiochemicals are produced by diverse taxa to mediate intra- and interspecific communication. These chemical cues are becoming increasingly important in integrated pest management (IPM) for manipulating key behaviors such as mating, foraging, and host selection in both plant–insect and insect-insect interactions. Semiochemical-based approaches regulate pest populations through techniques such as monitoring, mass trapping, and mating disruption. Understanding the chemical cues that mediate these interactions is crucial for developing sustainable and targeted pest management options. This review explores the role of semiochemicals in managing insect pests, with a focus on the fall armyworm (Spodoptera frugiperda), a globally significant pest native to the Americas. We discuss composition, variability, efficacy, specificity, and applications of plant volatiles and sex pheromones in pest management. Additionally, we address challenges associated with the adoption of semiochemical-based approaches and highlight emerging research directions to enhance their integration into IPM programs. By synthesizing current knowledge, this review underscores the potential of semiochemical-based strategies to reduce reliance on conventional insecticides while improving pest control efficiency. The strategic application of plant volatiles and sex pheromones in agricultural systems offers an opportunity to develop more ecologically sound and sustainable pest management practices, thereby fostering resilient cropping systems with minimal environmental impact.

Agricultural intensification in Lao PDR has steadily increased, driving of natural habitats into intensively managed agricultural landscapes. However, its impact on native pollinators, particularly the Asian honey bee (Apis cerana), remains poorly understood. This study examined the effects of two contrasting agricultural systems: agroecology and conventional agriculture on A. cerana abundance in central Lao PDR. Surveys were conducted year-round across ten plots (30 × 50 m) separated by 3 km between the two landscapes. Results revealed that native honey bee abundance was significantly higher in agroecology than in conventional agriculture plots. Abundance also varied throughout the year, with peaks during January, June, July and August. Time of the day further influenced bee activity, with morning sampling yielding higher counts than afternoon. In addition, flowering plant abundance and richness were positively associated with A. cerana abundance, highlighting the importance of floral resources in shaping foraging dynamics. These findings demonstrate that agricultural practices, floral availability, and temporal factors collectively influence native honey bee populations. Promoting agroecological systems that sustain floral resources is therefore critical for supporting pollinator health and maintaining stable crop pollination services in Lao PDR.

The serpentine leaf miner [Liriomyza trifolii (Burgess)] has become a major pest of tomato (Solanum lycopersicum L.) in India. Physiological responses of flowering S. lycopersicum plants to three degrees of L. trifolii infestation (low, moderate, severe) were explored in this study. Compared to non-infested (control) plants, foliar volatiles appeared to be more enriched in sesquiterpenes (mainly β-caryophyllene) at the expense of monoterpenes (mainly β-phellandrene) with more severe infestation. Molecular docking (in silico) indicated strong binding affinities of β-caryophyllene with chitin synthase, acetylcholinesterase and α-amylase in leaf miners, suggesting interfering roles of sesquiterpenes in feeding activity, nerve impulse propagation and development in these herbivores. Foliar chlorophyll contents, photosynthetic efficiency, polyunsaturated fatty acids (particularly membrane glycolipids) and soluble sugar levels were found to decline with higher degrees of infestation. Loss of leaf tissue by herbivory was characterized by rapidly rising antioxidant enzyme activities, by these parameters steadied or declined under the maximal observed damage conditions. Endogenous increments in antioxidant enzymes and total phenolics, including tannins (a specialized class of phenolics), were the main defense response under low or moderate degrees of herbivory, but more carbon-expensive flavonoids and terpenoids were up-regulated under higher degrees of leaf tissue damage. These patterns indicated diversion of metabolic pathways toward optimized phytochemical defense under resource limitation brought about by severe degrees of herbivory. Extensive leaf tissue damage also affected the biochemical profiles of flowers (such as sugar depletion and less diverse volatilome) – potentially causing loss of reproductive success. These observations are expected to contribute to in situ pest management via semiochemical-based approaches and timely mitigation of stress brought about by L. trifolii infestations in standing tomato crop.

Bacterial symbioses are important drivers of insect evolutionary ecology; although they can influence insect physiology and a range of phenotypic traits, little is known about their influence at a behavioral level. Aphids are suitable model systems to tackle this question, as they have evolved a diversity of associations with symbiotic bacteria. Here, experiments were conducted to assess the influence of aphid gut symbiont Serratia symbiotica (strain CWBI-2.3^T) on Aphis fabae’s behavior. Quantification of aphid size highlights the symbiont’s negative impact on size and biomass, confirming its adverse effect on host fitness; infection also impacts water uptake, but assessment of lipid contents suggests no influence on energy budget. Monitoring of feeding behavior via direct current electrical penetration graph (DC-EPG) shows that total duration of probing in the host plant is longer in infected aphids, particularly when the infection is at an advanced stage. Moreover, infection delays the time taken for the aphid to probe for the first time, while negatively impacting phloem sap uptake. Locomotor behavior assays on a target arena show an increase in intrinsic movement, dispersal, and velocity in infected aphids. Overall, these results suggest that aphid behavior can be severely affected by symbionts encountered in their environment. As S. symbiotica CWBI-2.3^T readily circulates in plants, we hypothesize that these behavioral modulations enhance its transmission to plants and potentially other aphids, which could also have implications for pest dispersal and the epidemiology of phytopathogens they vector. Our study marks a step forward toward a better understanding of the influential role of bacterial symbionts on insect behavior, an area that remains to be explored.

Multitrophic interactions occur when different systems are interconnected, forming a networks that performs various functions within an ecosystem, wherein all organisms involved are mutually affected. As primary producers, plants serve as an energy source for the entire consumer network, and their reproductive success directly and indirectly influences the structure of trophic chains. This study aimed to examine the temporal variation of floral herbivores in the plant species Ipomoea carnea subsp. fistulosa (Convolvulaceae) within a Caatinga area. Data were collected over 12 months at Fazenda Tamanduá, Paraíba, Brazil, using the ecological model of the species I. carnea subsp. fistulosa. Herbivory on previously marked plants was observed, and associated arthropods were actively collected using nets, entomological aspirators, and manual methods. Data analyses involved ANOVA for insect species richness and abundance, linear regression for plant production versus precipitation, and Shannon–Wiener and Simpson diversity indices. These arthropods were classified into ecological guilds: suckers, chewers, and borers. Our key findings indicate that: (I) flowers exhibited greater abundance and species richness compared to buds and fruits; (II) herbivore abundance and richness were higher during months with higher rainfall; and (III) chewers were more abundant than other herbivore guilds. Our results illuminate the influence of seasonality on the diversity of floral herbivores and underscore the importance of I. carnea subsp. fistulosa as a resource for local arthropod fauna during the dry season.

Myzus persicae Sulzer (Hemiptera: Aphididae) is one of the most destructive pests of Brassica crops, and Brassica juncea (L.) Czern (Brassicaceae) is an important crop in China. In this study, the life history data for M. persicae in one Brassica rapa L. (Brassicaceae) cultivar and three B. juncea cultivars were collected under laboratory conditions, and we also measured the glucosinolate content in the leaves of these host plants. Compared to the B. rapa plant Shanghaiqing (SHQ), the fecundity, net reproductive rate, intrinsic rate of increase, finite rate of increase, and total longevity of M. persicae were significantly lower, and the mean generation time was significantly longer on the B. juncea varieties [Huaye qingcai (HYQ), Renben guangtoujie (RBGTJ), and Shuidong jiecai (SDJ)]. In the choice test, M. persicae exhibited a significant host selection preference ranking in the order of SHQ > RBGTJ > HYQ > SDJ. The total glucosinolate contents in the leaves of the different plants, ranked from highest to lowest, were as follows: SDJ > HYQ > RBGTJ > SHQ. These results indicate that the glucosinolate content in Brassica leaves is negatively correlated with the life history performance and host plant selection of M. persicae. These findings provide important evidence that the M. persicae resistance of B. rapa and B. juncea is influenced by the total glucosinolate content in their leaves. We reported the life table of M. persicae in B. juncea plants for the first time; according to the developmental data of M. persicae in the laboratory, we can predict the control period of M. persicae on B. juncea plants, contributing to integrated pest management of B. juncea plants in future.

Mosquitoes are major disease vectors, causing millions of deaths annually. Resistance to chemical insecticides has reduced their effectiveness, prompting the need for safer alternatives, such as plant-derived phytochemicals. This research assessed the effectiveness of solvent extracts derived from mature Phyllanthus acidus leaves on different developmental stages of Culex quinquefasciatus, Culex vishnui, and Aedes albopictus. Six solvent extracts, namely petroleum ether, n-hexane, ethyl acetate, chloroform: methanol (1:1 v/v), acetone, and ethanol, were prepared using leaves. Among them, ethanol leaf extract showed the highest larvicidal, pupicidal, adulticidal, and repellent activities. The ethanol extracts demonstrated significant mosquito mortality, with LC₅₀ values of 21.32, 18.87, and 51.62 ppm for third instar larvae of Cx. quinquefasciatus, Cx. vishnui, and Ae. albopictus, respectively. The pupicidal activity was notably higher in ethanol-based leaf extracts, with an LC₅₀ value of 98.44 ppm with Cx. vishnui being the most susceptible species. In adulticidal and smoke toxicity tests, ethanol leaf extracts showed strong effects, causing 86.74–96.18% knockdown. Effective extracts were further purified using column and thin-layer chromatography. FTIR analysis identified several bioactive functional groups, such as hydroxyl, nitro, alkoxy, amino, and halogen groups. LC–MS analysis confirmed the presence of jatrorrhizine (C₂₀H₂₀NO₄), a potent alkaloid with known biological activity that interferes with mosquito physiology by disrupting neurotransmission, altering enzyme functions, impairing respiration, and compromising the integrity of the midgut. Importantly, bioassays showed no toxicity toward non-target organisms. The data suggest that the ethanol extract of the leaves of P. acidus shows promise as an eco-friendly agent for controlling medically significant vectors.

Drought-induced stress and nutrient deficiency are the most studied abiotic stresses due to their complex effects on plants. As the consequences of climate change become more apparent, few studies have considered the effects of these abiotic stresses on plant–insect interactions. The aster leafhopper (Hemiptera: Cicadellidae: Macrosteles quadrilineatus Forbes) is the main vector of Aster Yellows phytoplasma (AYp), a plant pathogen that can infect several plant species in the Western Canadian Prairies and the United States Upper Midwest, including cereals and canola. The mechanisms of insect nutrition and AYp transmission have an intimate association with the probing behavior of aster leafhoppers, namely with phloem-associated behaviors such as phloem ingestion and phloem salivation. The aim of this study is to examine the probing behavior of aster leafhoppers on canola grown under water stress, nutrient stress, and controlled conditions using the electropenetrography technique. Aster leafhoppers on stressed plants spent 62–63% of their time probing, while insects on control plants spent 45% of their time doing so. Aster leafhoppers on water-stressed plants were more likely to ingest from xylem tissues compared to insects in the other treatments. While aster leafhoppers from the different treatments spent 14–19% of their time ingesting from phloem, differences were observed in their ability to salivate into these tissues. Insects on nutrient-stressed plants spent more time salivating in the phloem compared to those on control plants, while aster leafhoppers on water-stressed plants rarely displayed this behavior.