Insects最新文献

Urban green spaces host complex arthropod communities, in which natural insect antagonists play a key role in regulating pest populations. The jumping plant-louse Cacopsylla pulchella is a sap-sucking pest widespread across Europe that attacks Cercis siliquastrum L., which is commonly used as an ornamental tree. Heavy infestations may contribute to host tree decline and cause indirect damage in urban environments by reducing aesthetic value and by extensive deposition of honeydew secretions on surrounding surfaces. As with many phytophagous insects occurring in urban contexts, information on the natural enemies of this species remains limited, particularly in Italy, and requires further documentation. Here, we investigated the parasitoids associated with C. pulchella in central and southern Italy based on surveys conducted between 2022 and 2025. Specimens were obtained from infested plant material and identified using an integrative taxonomic approach combining detailed morphological examination with DNA barcoding. Prionomitus mitratus was confirmed as the primary parasitoid of C. pulchella, while two species, Pachyneuron muscarum and Pachyneuron aphidis, were identified as hyperparasitoids. In addition, a single specimen of Anastatus bifasciatus was also recorded emerging from the psyllid as a hyperparasitoid. Molecular analyses generated the first publicly available mitochondrial and nuclear sequences for P. mitratus. For Pachyneuron, molecular results showed variable correspondence with available reference sequences, reflecting the uneven representation of species-level data for Pteromalidae in public databases. By integrating morphological and molecular evidence, this study clarifies trophic relationships within the C. pulchella parasitoid complex. It provides vouchered molecular references to support future taxonomic and ecological research in urban ecosystems.

Delphastus Casey (Coleoptera: Coccinellidae: Serangiini) comprises small predatory ladybird beetles that feed on immature whiteflies. Several Delphastus species are utilized as biological control agents. However, Delphastus pallidus (LeConte) has been understudied for the past several decades. Recent landscape surveys in South Florida revealed a marked increase in D. pallidus populations associated with multiple whitefly species. We evaluated whitefly species preferences of D. pallidus using choice and no-choice assays conducted in incubators and insectaries. Seven whitefly species were confirmed as prey and ranked in order of preference: Bemisia tabaci Gennadius > Aleurothrixus trachoides (=Aleurotrachelus trachoides) (Back) > Singhiella simplex (Singh) > Paraleyrodes bondari Peracchi > Aleurodicus rugioperculatus Martin > Asiothrixus antidesmae (Takahashi) > Aleurodicus dugesii Cockerell. Findings indicate that D. pallidus feeds on a taxonomically and morphologically diverse set of whiteflies, including both waxy and non-waxy species, which likely facilitates establishment and dispersal in ornamental and agricultural landscapes. This study is the first to document D. pallidus as a potentially native U.S. predatory beetle that attacks at least seven whitefly species. Knowledge of its prey preferences will inform mass-rearing strategies and potential deployment for whitefly biocontrol.

The insect gut microbiome contributes to various host physiological processes and behaviors, such as digestion, nutrient absorption, immunity, mate choice, and fecundity. The social environment can shape gut microbial communities. Mixed-sex vs. female-only rearing is an important social context because it differs in exposure to the opposite sex and mating opportunities, which may in turn affect female physiology that may influence their gut microbiome. Despite the growing recognition of these social-microbial interactions, most studies have relied on 16S rRNA amplicon sequencing or qPCR, which provide only coarse taxonomic resolution and limited functional insight. In this study, we used whole-genome shotgun metagenomics to examine changes in microbial diversity and functional gene composition in the female field cricket Teleogryllus occipitalis (Serville) (Orthoptera: Gryllidae) reared under two social conditions: mixed-sex rearing and female-only rearing. Species richness and diversity analyses revealed that community composition separated between females from mixed-sex and female-only rearing. Functional profiling indicated higher relative abundances of genes annotated to nutrient processing and inter-bacterial competition in females from mixed-sex rearing, whereas females from female-only rearing showed relative enrichment of genes annotated to stress resistance and nitrogen fixation. These findings provide a genome-resolved foundation for testing how social rearing conditions covary with gut microbiome composition and functional potential in female crickets.

Comparative morphological analysis of the labrum and labium among nine aphid species-Uroleucon sp., Glyphina betulae, Myzus cerasi, Panaphis juglandis, Chaitophorus sp., Lachnus roboris, Forda sp., Paracletus cimiciformis, and Trama sp., belonging to six subfamilies-reveals marked interspecific variation in structure, segmentation, and sensilla equipment. The labrum is generally triangular and plate-like, ranging from 88.8 μm (M. cerasi) to 358.1 μm (L. roboris). However, Trama sp. exhibits a distinctive conical labrum (311.1 μm) bearing three pairs of sensilla trichodea (St2)-unique among the examined taxa. Most species possess a four-segmented labium, while Trama sp. and L. roboris exhibit five segments. The second segment is the longest and most elaborate, bearing dense arrays of sensilla or spiniform tubercles in several species. Sensilla trichodea (St1-St5) are widespread across taxa, showing the highest densities in Chaitophorus sp St1, Trama and L. roboris St2, Uroleucon sp St3, and P. cimiciformis St4, whereas Trama sp. uniquely combines sensilla St2, St3, St5, and sensilla basiconica (Sb2). Sensilla basiconica (Sb1) are consistently positioned at the base of the labrum and the fourth labial segment, except in Trama sp., which presents sensilla St3. Distinct cuticular modifications-including apical cuticular processes and granular protrusions-occur only in Trama sp. and L. roboris, suggesting lineage-specific adaptations. These morphological patterns indicate that aphid mouthpart diversity reflects functional specialisation linked to host-plant structural variation.

Plant-derived volatile organic compounds (VOCs) are widely used as insect attractants for population monitoring, offering an efficient and eco-friendly approach to pest management. Since thrips are the dominant pest species in alfalfa fields, this study aimed to identify a suitable attractant trap design that could be employed to monitor Odontothrips loti and Frankliniella occidentalis. The field experiment showed that p-Menth-8-en-2-one, dispensed through PE (Polyethylene) vials positioned at the top of the alfalfa canopy, attracted the most thrips, with the optimal concentrations of 1 µg/µL for O. loti and 50 µg/µL for F. occidentalis, respectively. When both species occur in alfalfa, PVC pipes dispensing p-Menth-8-en-2-one at a concentration of 1 µg/µL provide an effective attractant for both species, offering an indication of presence and relative abundance. Understanding the incidence and abundance of both species in the field provides growers an opportunity to target treatments to protect crops before significant damage occurs, reduce insecticide overuse, and support integrated pest management strategies for these two high-impact pests.

Tomato leafminer (Tuta absoluta) significantly affects tomato (Solanum lycopersicum) and eggplant (Solanum melongena) crops worldwide, with its feeding patterns being closely associated with its gut microbiota. We aimed to compare the cultivable gut bacteria of T. absoluta larvae fed on tomato and eggplant to investigate their role in host adaptation. Gut bacteria were cultivated on Luria-Bertani broth, nutrient agar, and Brain Heart Infusion media under different temperature conditions, followed by morphology- and 16S rRNA-based identification. Notably, both feeding groups revealed distinct gut bacterial community structures. Tomato-fed larvae harbored bacteria spanning eight species, five genera, four families, and two phyla. In contrast, eggplant-fed larvae exhibited greater microbial diversity, encompassing 15 species, 10 genera, 9 families, and 3 phyla, including unique genera such as Pseudomonas and Pectobacterium, which was attributed to the host plant contribution. Enterococcus mundtii was the most dominant bacterium, and species such as Bacillus wiedmannii and Micrococcus luteus were most thermotolerant. Overall, these findings highlight the importance of multi-condition culture approaches for thoroughly characterizing insect gut microbiota and underscore the role of host plants in pest adaptability by modulating gut microbial communities, providing new insights for developing sustainable control strategies utilizing "plant-insect-microorganism" interactions.

The Asian tiger mosquito (Aedes albopictus) is an important vector of arboviruses, including dengue, chikungunya, and Zika. Its rapid global expansion has been facilitated by climate change and human activities. Phylogenetic studies of Ae. albopictus have largely relied on mitochondrial cytochrome c oxidase subunit 1 (COX1) and NADH dehydrogenase subunit 5 (ND5) markers, while the utility of cytochrome b (CYTB) remains underexplored. We collected Ae. albopictus from 13 sites in seven provinces of South Korea and analyzed COX1, ND5, and CYTB sequences. Genetic diversity indices were calculated, and phylogenetic relationships were reconstructed using maximum-likelihood trees and haplotype networks with a dataset obtained from GenBank. COX1 revealed 46 haplotypes, including six novel variants, with the highest diversity in southern coastal regions such as Busan and Suncheon. ND5 showed limited variation, with only two haplotypes. CYTB revealed three haplotypes, including region-specific variants in Busan and Wonju, supporting its role as a complementary marker. The Busan haplotype H41 bridged domestic and international lineages, suggesting Busan as a likely entry point. This study demonstrates that integrating COX1, ND5, and CYTB improves the resolution of Ae. albopictus phylogeography in Korea and highlights the need for continued molecular surveillance to guide vector control strategies.

Scaphoideus titanus Ball, 1932 (Hemiptera: Cicadellidae), the main vector of the phytoplasma (FDp) causing Flavescence dorée, is considered a challenging problem in European vineyards. Natural insecticides permitted for S. titanus control in Italian organic viticulture are generally considered of low-to-moderate efficacy. Morever, it should be mentioned that their optimal use requires a careful approach when preparing the insecticide solutions. Synthetic insecticides used in Italian viticulture are included in only two IRAC groups, indicating potential risks for resistance. Therefore, there is a need to identify alternatives or control tools complementary to synthetic insecticides. In this study, we summarize the results obtained in five field experiments (2021-2025) using the main alternatives to synthetic insecticides (i.e., pyrethrins, kaolin, azadirachtin, Beauveria bassiana, and potassium salts of fatty acids). In all seasons, pre-insecticide application populations did not differ significantly among treatments, whereas differences emerged after insecticide applications. The overall results showed that pyrethrin-based insecticides were the most effective in reducing S. titanus nymph densities. Kaolin provided intermediate but comparatively stable levels of control across the years, whereas B. bassiana showed moderate yet highly variable efficacy. The findings obtained here can be considered in designing management strategies for S. titanus in organic viticulture that require an integrated approach combining pyrethrins with complementary, lower-impact tools to achieve effective and sustainable control over time. At the same time, natural insecticides can be incorporated into IPM strategies in conventional vineyards to prevent resistance.

The scientific community has long recognized that diversity drives innovation, creativity, and progress [...].

Analyzing the composition and structure of the gut bacterial community in Antheraea pernyi is essential for improving its economic traits, as well as for understanding gut bacteria-host interactions in lepidopteran insects. This study utilized the Illumina MiSeq PE 300 platform to conduct 16S rRNA gene sequencing for a comparative analysis of gut bacterial community in laboratory-reared and field-released (spring and autumn) Antheraea pernyi larvae of the same strain. The study revealed the specific effects of rearing environment and seasonal variation on the structural and functional dynamics of the larval gut bacterial communities. The composition of the dominant gut bacteria varied significantly with rearing environment and season. Laboratory-reared and spring field-released groups exhibited similar bacterial community structures, whereas the autumn field-released group showed a significant trend toward specialization, characterized by enrichment of specific bacterial taxa. Linear discriminant analysis effect size identified statistically significant biomarkers across samples. Taxonomic analysis revealed that Actinomycetota, Actinobacteria, Mycobacteriales, Dietziaceae, and Dietzia were characteristic of the gut bacteria profile in spring field-released, Lactobacillales, Enterococcaceae, and Enterococcus were enriched in the autumn field-released group, and the laboratory-reared group exhibited a relative dominance of Alphaproteobacteria. Functional prediction indicated that gut bacterial community structure likely influences its metabolic potential, which may suggest an adaptive response of the Antheraea pernyi to distinct ecological environments. This study provides important insights into the highly complex nature of insect-microbe interactions.