Search Results (828)

The preservation of biological control agents in agroecosystems while simultaneously ensuring the use of insecticides with selective chemical profiles is crucial for sustainable pest management. In this study, we aimed to evaluate the selectivity of insecticides used in the management of Phthorimaea (Tuta) absoluta in tomato crops during the adult stage of Trichogramma pretiosum. The selectivity tests were conducted according to the standards of the International Organization for Biological and Integrated Control/West Palearctic Regional Section. The bioassay was used to assess the direct effects of treatments on T. pretiosum adults through tarsal contact. Specifically, 42 chemical and/or biological insecticides commonly applied in tomato cultivation were used to manage P. absoluta. The insecticides identified as selective (Class 1) for adult T. pretiosum under laboratory conditions were recommended for use in integrated pest management (IPM) programs in tomato crops. These included Hayate^®, Agree^®, Dipel^®, Xentari^®, Tarik^®, Bioexos^®, Verpavex^®, Spodovir^®, Verpavex^® + Spodovir^®, Tuta Vir^®, BioBrev^®, Diplomata^®, VirControl C.i^®, and VirControl S.F^®. Insecticides belonging to the following chemical groups were not selective, that is, they were harmful to T. pretiosum adults: avermectins, milbemycins, diacylhydrazines, oxadiazines, semicarbazones, spinosyns, diamides, chlorfenapyr, nereistoxin analogs, pyrethroids, carbamates, butenolides, isoxazoline, azadirachtin, quinolizidine alkaloids, METI, and benzoylureas. Therefore, these insecticides should be used with caution in IPM programs that target P. absoluta in tomato crops. Full article

Parasitoids use different signals to locate their hosts, and these signals can modulate their behavioral decisions. Thus, patch selection and foraging in patches with different characteristics depend on their ability to gather and use such information efficiently. In this study, we evaluated whether the parasitoid Eretmocerus eremicus (Hymenoptera: Aphelinidae), a natural enemy of Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) on tomato plants (Solanum lycopersicum), uses scent cues to select and forage in patches that differ in host density and predation risk. Using choice bioassays in a wind tunnel under a continuous airflow, we recorded selection patch and selection time, as well as foraging parameters, including residence time, oviposition events, and attacks. Our results show that E. eremicus discriminated between sites with and without hosts using scent cues, but discrimination between patches with different host numbers was not detected under our assay conditions. It also distinguished between patches with maximum risk and those without risk, but not between subtle differences in risk. These findings suggest that E. eremicus, responded mainly to contrasting olfactory cues rather than to subtle odor differences. From an applied standpoint, our results motivate deeper investigation into how host- and predator-associated olfactory cues could fine-tune parasitoid deployment in biological control. Full article

Sclerodermus guani Xiao et Wu, 1983 plays a significant role in the biological control of agricultural and forestry pests. To investigate whether different sugar types significantly affect the longevity, fecundity, and nutrient reserves of female S. guani adults, this study provided 1 mol/L solutions of sucrose, fructose, glucose, mannose, or trehalose under laboratory conditions, with a distilled water group serving as the control. The longevity and nutrient content of parasitoids were measured after varying feeding durations, while fecundity was assessed in preliminary experiments. The results demonstrated that prolonged sugar feeding significantly extended parasitoid longevity, with fructose, glucose, and sucrose exhibiting the most pronounced effects and no significant differences among them. Nutrient analysis revealed that sugar consumption significantly increased total carbohydrate content, slowed lipid depletion, and promoted protein accumulation. Sucrose, fructose, and glucose outperformed other sugars and the control in these aspects. Fecundity assays indicated that glucose and trehalose significantly shortened the pre-oviposition period and enhanced egg production. In conclusion, nutritional supplementation markedly improves the longevity and reproductive performance of S. guani, with 1 mol/L glucose identified as the optimal dietary source. Full article

Scoliidae are fossorial aculeate wasps (Hymenoptera: Apocrita) whose larvae develop as parasitoids of beetle grubs, mainly from the family Scarabaeidae. Despite their distinctive appearance and economic importance, the taxonomy and biology of Scoliidae are less well understood compared to other Hymenoptera. Recently, a new species of Scoliidae, Dielis tejensis Szafr., was described based on about a dozen male specimens from Texas (Nearctic realm). This article reports on mtDNA-verified discovery of the female D. tejensis. As in the case of other members of the tribe Campsomerini, D. tejensis exhibits strong sexual dimorphism in body structure and color pattern. Females of D. tejensis most closely resemble Dielis plumipes (Drury) and were previously confused with D. plumipes fossulana (Fabr.), with which D. tejensis is partially sympatric. D. tejensis has more than one generation per year, characterized by a male-biased sex ratio, perhaps resulting from the female immature stages entering a state of aestivation. The multi-generational developmental cycle of D. tejensis correlates with the existence of a partial seasonal polyphenism in this species. The data presented also shows a similarity in the distribution ranges of D. tejensis and one of its main nectaring plants, Hymenopappus artemisiifolius DC (Asteraceae), that may suggest similarity in the environmental requirements of both organisms or specialized trophic relationship between the still-unknown beetle host of the wasp larvae and H. artemisiifolius or another plant with a similar range. D. tejensis has been included in the accordingly modified key to the Nearctic species of Dielis Sauss. & Sichel, which is also presented here. Full article

Syspastoxyelidae is an extinct basal hymenopteran lineage currently known only from mid-Cretaceous Burmese amber. Here, we describe a new genus and species, Cilioxyela setosa gen. et sp. nov., based on a well-preserved female specimen from the Hukawng Valley, northern Myanmar. The new taxon is assigned to Syspastoxyelidae based on diagnostic characters, including strongly proximally condensed forewing venation, a composite first flagellomere formed by fused ancestral segments, tibiae bearing dense robust spines, and segmented cerci. Cilioxyela gen. nov. differs from all previously described genera by a unique character combination, most notably, a distal forewing veinless membrane lacking longitudinal corrugation and conspicuously elongated marginal setae, together with a narrowed forewing, elongate pterostigma and anal cell, and distinctive antennal segmentation. These features support the establishment of a new genus. Comparative analysis indicates that distal forewing morphology in Syspastoxyelidae is more variable than previously recognized. The presence or absence of longitudinal corrugation in the distal forewing membrane likely reflects genus-level differentiation rather than a stable family-level synapomorphy. The new genus also supports a tentative division of Syspastoxyelidae into at least two morphologically cohesive groups, pending testing through additional fossil discoveries and quantitative phylogenetic analyses. The discovery of Cilioxyela setosa expands the known morphological disparity of Syspastoxyelidae and highlights evolutionary plasticity in distal forewing architecture among early Hymenoptera, contributing to a better understanding of morphological diversification in mid-Cretaceous forest ecosystems. Full article

Two new species of the genus Encarsia Förster (Hymenoptera: Aphelinidae), E. cinnamomi Wang & Huang, sp.n. and E. ophiopogonis Wang & Huang, sp.n., are described and illustrated from Fujian, China. The mitochondrial genomes of these two new species and E. diaspidicola are sequenced (14,049 bp, 14,746 bp and 14,849 bp, respectively), both showing a strong A + T bias (84.1%, 84.7% and 84.8% respectively). We infer the phylogenies of several Encarsia species of Aphelinidae and other family of Chalcidoidea based on PCG123 datasets using Bayesian inference (BI) and maximum likelihood (ML) methods. ML and BI analysis both support Aphelinidae formed a sister group to Torymidae. Full article

In the complex interplay among parasitic wasps, their insect hosts, and pathogenic microbes, the system involving Sclerodermus guani (Hymenoptera: Bethylidae) (a parasitoid wasp), Monochamus alternatus (Coleoptera: Cerambycidae) (the pine sawyer beetle, its host), and Beauveria bassiana (Hypocreales: Cordycipitaceae) (a fungus) presents a unique scenario where wasp offspring develop within a nearly sealed host gallery. This nursery is vulnerable to fungal invasion, often introduced by the foraging female wasps or M. alternatus itself, creating a three-way interaction where the fungus can infect both M. alternatus and S. guani. To assess how the route and timing of fungal exposure impact the S. guani population, we simulated this system by introducing different concentrations of B. bassiana either directly to the female wasps or to M. alternatus prior to parasitism. We further examined the effect of exposure timing by applying the fungus at different developmental stages of the S. guani offspring. Key population parameters, including the reproductive capacity of female wasps, the survival and developmental fitness of S. guani offspring and the germination period of hyphae, were measured. The results indicated that the most severe damage to populations of S. guani occurs when its host, M. alternatus, is infected by B. bassiana. Among the various developmental stages, S. guani offspring exhibited the greatest vulnerability during mid-to-late larval stages, whereas the egg and pupa within cocoon stages demonstrated a higher tolerance. We conclude that both the pathway and the timing of fungal exposure are critical factors influencing its impact. These findings provide valuable insights for optimizing the integrated use of biological agents in pest management, informing strategies that mitigate adverse effects on beneficial parasitoid wasps. Full article

Background: Snake envenomation represents a significant health concern in some regions of the world, with fatal cases occasionally requiring forensic investigation to estimate the postmortem interval (PMI). However, the influence of venom on carrion decomposition dynamics and arthropod succession patterns remains poorly understood, potentially compromising postmortem interval (PMI) estimations in such cases. Objectives: This study investigated the effects of Naja haje and Cerastes cerastes venoms on decomposition progression and necrophagous arthropod succession. Methods: Fifteen rabbits were allocated into three experimental groups. Two groups received median lethal intravenous doses (LD₅₀) of N. haje or C. cerastes venom, whereas the control group received a saline injection followed by CO₂ euthanasia. The carcasses were subsequently placed under natural field conditions and monitored daily for 15 days. Results: The presence of venom significantly altered decomposition dynamics. C. cerastes venom accelerated early decomposition, shortening both the fresh stage (1 ± 0.22 days vs. 2 ± 0.31 days in controls,) and bloating stage (3 ± 0.35 days vs. 5 ± 0.35 days), while extending both the decay stage (6 ± 0.3 days vs. 6 ± 0.17 days) and the dried stage (5.0 ± 0.44 days vs. 2 ± 0.039 days). N. haje venom showed intermediate effects. Overall arthropod abundance peaked on day 5 and declined thereafter. Control carcasses exhibited significantly higher arthropod abundance than carcasses envenomed with C. cerastes or N. haje. Conclusions: Snake envenomation significantly influenced decomposition kinetics and arthropod colonization patterns. Envenomation with C. cerastes venom produced more pronounced alterations than envenomation with N. haje venom. Full article

The two-spot cotton leafhopper, Amrasca biguttula (Ishida) (Hemiptera: Cicadellidae), was recently detected in Florida and other southeastern states, USA. This is a quarantine pest of regulatory significance, since it can infest staple crops, such as okra, cotton, eggplant, and tropical hibiscus. While collecting infested okra plants in Homestead, Florida, five female Anagrus (Hymenoptera: Mymaridae) parasitoids emerged from eggs of Am. biguttula. The specimens were identified morphologically and molecularly by sequencing the cytochrome c oxidase subunit I (COI) gene and internal transcribed spacer 2 (ITS2) region of nuclear ribosomal RNA. Two Anagrus species were identified: Anagrus vulneratus and Anagrus sp. near vulneratus. These parasitoids are not known to occur in the Old World, the origin of Am. biguttula. Rather, they are native to North America. The available evidence suggests that the collected specimens switched from unknown local hosts in southern Florida to parasitize eggs of the invasive Am. biguttula. Future research to ascertain the identity of A. sp. near vulneratus and evaluate the efficiency of both parasitoids as natural enemies of Am. biguttula is warranted. Full article

The diamondback moth, Plutella xylostella (L.), is a significant pest of brassica crops that is found across the globe. Due to the development of insecticide resistance, control tactics have shifted focus towards integrating pest management techniques such as biological control. Diadegma insulare (C.), Oomyzus sokolowskii (K.), and Microplites plutellae (M.) are parasitoids of P. xylostella found in the Eastern United States. From 2022 to 2025, we surveyed P. xylostella larvae and pupae in locations across Virginia to assess the current rates of parasitism in brassica fields. Specimens were brought to the laboratory and reared to assess parasitoid emergence rates. Only D. insulare specimens were found during the study. Adult P. xylostella, larvae and pupae, adult D. insulare, D. insulare pupae, unknown parasitoids, and unknown deaths were recorded and used to calculate the rates of parasitism at each location. We concluded that the parasitism rate varied by location and year, which was expected due to regional conditions and seasonality. Rates averaged between 30.1 and 65% by year, with the lowest individual rate being 15% in 2025 and the highest at 100% in 2022. This suggests that D. insulare is actively present in Virginia and could be a successful biological control agent when paired with other integrated pest management techniques to reduce P. xylostella populations. Full article

Ant–hemipteran mutualism is mediated by honeydew through long-term coevolution. To clarify the feeding preferences for the main honeydew components (sugars and amino acids) in the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), this study employed a self-developed feeding preference assay system to systematically determine the feeding and attraction preferences of workers for ten sugars, eleven amino acids, and their different concentrations and combinations in both laboratory and field experiments. Results showed that: (1) S. invicta workers exhibited a significant feeding preference for sucrose and leucine among all tested sugar and amino acid solutions; (2) Feeding preferences for both sucrose and leucine were concentration-dependent. Specifically, preferences for 20% sucrose and 0.5% leucine were significantly higher than for lower concentrations, while not significantly different from higher concentrations; (3) The feeding preference for 10% sucrose or 0.5% leucine alone was higher than that for multi-sugar mixtures or a mixture of all eleven amino acids. However, a mixture of sucrose and leucine solutions significantly enhanced field attraction compared to single solutions of sucrose or leucine. The self-developed feeding preference assay system provides a new tool for measuring feeding preferences in ant colonies under near-natural conditions. Overall, this study systematically clarifies the feeding preference for key nutrients in S. invicta workers and establishes a critical theoretical basis for understanding its foraging ecology and developing highly effective liquid baits. Full article

LED-enhanced sticky traps improve monitoring of greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), but their effects on its parasitoid, Encarsia formosa Gahan (Hymenoptera: Aphelinidae), are unclear, which may compromise biological control. Methods: We quantified E. formosa visual responses in climate-chamber multiple-choice arenas using six LED colors at equal photon flux (8.1 μmol m⁻² s⁻¹) and in greenhouse choice/no-choice assays comparing a standard yellow sticky trap with a green LED-enhanced yellow trap, with and without host-infested tomato leaves. We further tested modified LED traps (green LEDs with white or green backgrounds) and assessed intensity-dependent responses (18.0–25.6 μmol m⁻² s⁻¹). Results: E. formosa showed the highest attraction to green LEDs (peak ≈ 521–524 nm) and a significantly lower response to other colors. In greenhouse assays, E. formosa preferred the standard yellow sticky trap over the LED-enhanced yellow trap; in no-choice tests, only 9% were recaptured on the LED-enhanced yellow trap, both without and with hosts. Modified traps with white or green backgrounds substantially increased E. formosa recapture (≈54% higher than the yellow-background LED trap). Encarsia formosa attraction to the white-background LED trap declined with increasing intensity (61% at 18.0 to 4% at 25.6 μmol m⁻² s⁻¹), whereas whitefly captures were stable to slightly higher. Conclusions: The standard LED-enhanced yellow trap is compatible with E. formosa releases and does not disrupt biocontrol. Modified LED traps show promise for simultaneous monitoring of E. formosa and whiteflies, warranting validation under commercial conditions. Full article

To investigate the long-term effects of climate change on biological communities, our primary aim was to identify the most reliable indicators among available biodiversity, dominance, and evenness indices. We examined three distinct response types to climate change, represented by three taxonomic groups: Aculeata (Hymenoptera), Syrphidae (Diptera), and nocturnal macrolepidoptera (Lepidoptera). Using faunistic datasets derived from our own 3–5 decades of field surveys, we calculated 12 key indices with the vegan package in R 4.2.1. The robustness of these indices was assessed through 1000-fold bootstrap simulations and pairwise correlation analyses. Our results revealed that the Gini–Simpson, Simpson diversity, McIntosh diversity, and McIntosh evenness indices consistently demonstrated high temporal stability and strong correlations across all three climate response types. Therefore, we recommend these indices as primary climate indicators. In contrast, Chao1 estimates, Margalef Index, Menhinick Index, and the Shannon–Wiener diversity index are suitable only for analyzing specific response patterns. Meanwhile, the Berger–Parker, Buzas–Gibson indices, and Hill numbers showed high variability or limited ecological responsiveness, making them unreliable for tracking climate change impacts. Our findings underscore that selecting biodiversity indices must be tailored to the research question and the characteristics of the ecosystem in order to ensure valid and informative ecological analysis. Full article

The genus Phanerotoma Wesmael, 1838 (Hymenoptera, Braconidae, Cheloninae, Phane- rotomini) is distributed across all six major zoogeographical regions, with the highest species diversity recorded in the Palaearctic Region. DNA barcoding provides a robust method for species identification, yet its effectiveness for the genus Phanerotoma is limited by the scarcity of reliable, species-level data from specific regions in public databases. This gap makes it essential to contribute comprehensive genetic resources to advance taxonomic research. This study presents a comprehensive COI dataset of 92 sequences for the genus Phanerotoma, employing both the Automatic Barcode Gap Discovery (ABGD) method for species delimitation and the bPTP model for phylogenetic inference. The integrated analytical approach revealed 18 distinct species, including five new species; all species new to science are described and illustrated, and updates of the most recent key to the Chinese species are included. Full article

Pollen is one of the main food sources for honeybees. The honeybee gut microbiota plays a crucial role in maintaining digestive function and host health during long-term coevolution. While the consumption and utilization of pollen have been extensively studied, there is limited information about the effects of pollen on the gut microbiota of Apis cerana. In this study, we used 16S rRNA amplicon sequencing to evaluate the effects of four natural pollens (oilseed rape pollen, camellia pollen, lotus pollen and buckwheat pollen) and two pollen substitutes (Diet 1 and Diet 2) on the hindgut microbiota of newly emerged A. cerana worker bees, following feeding periods of 5, 10 and 15 days. The results showed that Firmicutes and Proteobacteria are dominant in the gut microbiota of A. cerana. A. cerana workers fed with pollen diets had a higher diversity of gut microbiota than those fed with pollen substitutes. There have been significant differences in the gut microbiota structure and relative abundance of the core microbial community among A. cerana workers supplied with different diets. Our results confirm that gut bacterial communities of A. cerana can be influenced by pollen diets and may play an important role in host adaptation. Full article