Search Results (69)

In this study, we investigated the current and future potential distribution of three parasitoid species of Drosophila suzukii, which represent promising candidates for the biological control of this pest: Leptopilina japonica (Hymenoptera, Figitidae), Pachycrepoideus vindemmiae (Hymenoptera, Pteromalidae), and Trichopria drosophilae (Hymenoptera, Diapriidae). To this end, we employed Ecological Niche Modeling using the Random Forest algorithm and climatic data from WorldClim v. 2.1 under climate change scenarios (SSP2-4.5 and SSP5-8.5), analyzing the spatial overlap between the pest and its natural enemies. The results indicate that the parasitoids exhibit distinct geographic distributions, although most species show higher suitability for temperate regions of the Northern Hemisphere. Species such as T. drosophilae and L. japonica stand out for their broad distribution and high overlap with the pest, whereas P. vindemmiae and display more restrictive climatic ranges and lower control efficiency. With ongoing climate change, all parasitoids tend to migrate toward higher latitudes, with significant range contractions in tropical regions. Thus, our results demonstrate the usefulness of Ecological Niche Modeling in the selection of biological control agents by considering host-specific preferences and environmental requirements in the development of management strategies adapted to future scenarios. Full article

Several fruit fly species in the Drosophilidae and Tephritidae families are classified as invasive pests worldwide. However, limited information is available on the occurrence of those dipteran species, their interactions, and their host plants in the Pampa Biome of southern Brazil. Therefore, we investigated interactions between invasive fruit flies and host plants. After two years (2022–2023) of fruit surveys, 3802 fruits from 16 plant species were harvested in the Pampa Biome’s urban and rural areas. The collected fruits were conditioned in the laboratory. Emerged adult flies were identified and associated with the respective fruit species. The most abundant species detected were Zaprionus indianus (Gupta), followed by Zaprionus tuberculatus (Malloch), Drosophila suzukii (Matsumura), and Ceratitis capitata (Wiedemann). The invasive drosophilids D. suzukii, Z. indianus and Z. tuberculatus interacted with 10 host plant species each, whereas C. capitata was associated with seven host species. Zaprionus indianus showed the highest infestation rate on fruits collected from the ground, whereas D. suzukii had the highest infestation rate in fruits attached to plants. New host plants were identified for Z. tuberculatus and C. capitata. The findings of this study provide a valuable framework for more effective management and control strategies. Full article

Bactrocera dorsalis Hendel is a devastating invasive pest that costs billions of dollars in agricultural losses worldwide. Current control strategies rely heavily on male-specific attractants such as methyl eugenol, which are less effective against females, underscoring the need for female-targeted control approaches. Here, we investigated the molecular mechanisms underlying female attraction to cis-linalool oxide by functionally characterizing the odorant receptor OR45a, identifying it as a molecular target for female-oriented pest management. We conducted spatiotemporal expression analysis of OR45a in response to cis-linalool oxide, followed by RNAi and behavioral assays. Phylogenetic analysis of OR45a orthologs from 10 Dipteran species, combined with structural topology prediction and solvent-accessible surface area (ASA) analysis, helped identify functional domains and residues. Site-directed mutagenesis and two-electrode voltage clamp (TEVC) recordings validated receptor–ligand interactions. Results showed that OR45a was specifically upregulated in antennae, with peak expression at 10 days post-eclosion, coinciding with oviposition periods. RNAi significantly reduced OR45a transcript levels and female behavioral responses to cis-linalool oxide. Phylogenetic analysis showed that OR45a is highly conserved within Tephritidae but diverges from Drosophilidae, with closest similarity to Anastrepha ludens, indicating ecological specialization. Structural modeling predicted a canonical seven-transmembrane architecture with three extracellular loops forming the ligand-binding pocket. Among five key residues identified, Leu122 and Ile146 were essential for ligand recognition, while Tyr107 contributed to protein stability. These findings reveal a female-specific odorant receptor mechanism in B. dorsalis and provide molecular targets for OR45a-based attractants, addressing a critical gap in female-focused pest management. Full article

The increase in the world population and consequent rise in food demand have led to the extensive use of chemical pesticides, causing environmental and health concerns. In response, biological control methods, particularly those involving microbial agents, have emerged as sustainable alternatives within integrated pest management. This study highlights the potential of Lysinibacillus fusiformis as a biocontrol agent against the dipteran Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), a pest responsible for damaging soft-skinned fruits. Experimental treatments using vegetative cells, spores, and secondary metabolites of L. fusiformis on D. suzukii larvae demonstrated significant larvicidal effects, accompanied by observable changes in gut morphology under microscopy. Moreover, preliminary immunological assays showed the interference of this bacterium with the host immune system. All the results indicate the suitability of L. fusiformis for its possible integration into sustainable agricultural practices, although additional research is required to understand its applicability in the field. Full article

In the forest ecosystems of Central European Russia, the influence of forest edges on the spatial distribution of Drosophilidae was studied for the first time. The research was conducted during the period of 2021–2022 in the Republic of Mordovia. Beer traps baited with fermented beer and sugar were used to collect Drosophilidae. Two study plots were selected, differing in their forest edges, tree stands, and adjacent open ecosystems. In both cases, the forest directly bordered an open ecosystem. Edges serve as transitional biotopes, where both forest and meadow (open area) faunas coexist. Knowing that many drosophilid species prefer forest habitats, we designated forest interior sites as control points. Traps were set at heights of 1.5 m (lower) and 7.5 m (upper) on trees. A total of 936 specimens representing 27 species were collected. Nine species were common across all traps, while ten species were recorded only once. At the forest edges, 23 species were captured across both heights, compared to 19 species in the forest interiors. However, the total abundance at the forest edges was 370 specimens, while it was 1.5 times higher in the forest interiors. Both abundance and species richness varied between plots. Margalef’s index was higher at the forest edges than in the forest interiors, particularly at 1.5 m height at the edge and at 7.5 m height in the forest interior. Shannon and Simpson indices showed minimal variation across traps at different horizontal and vertical positions. The highest species diversity was observed among xylosaprobionts (9 species) and mycetophages (8 species). All ecological groups were represented at the forest edges, whereas only four groups were recorded in the forest interiors, with the phytosaprophagous species Scaptomyza pallida being absent. In general, both species richness and drosophilid abundance increased in the lower strata, both at the forest edge and within the interior. Using the R package Indicspecies, we identified Gitona distigma as an indicator species for the forest edge and Scaptodrosophila rufifrons as an indicator for the forest interior in the lower tier for both plots. In addition, Drosophila testacea, D. phalerata, and Phortica semivirgo were found to be indicator species for the lower tier in both plots, while Leucophenga quinquemaculata was identified as an indicator species for the upper tier at the second plot. Full article

Drosophilidae is a relatively small family within Diptera. However, species of this family occupy a wide range of ecological niches and are frequently found in synanthropic habitats. Additionally, some species are known agricultural pests. The dataset is based on collections of Drosophilidae from eleven regions of Russia. The dataset was uploaded to the GBIF platform in 2024. Published sources specifying exact localities and collection dates were also used. The database includes records dating back to 1867, with the majority of specimens collected by the authors between 2001 and 2024. Collection methods included net sweeping and bait trapping. The dataset contains 2830 occurrence records, with a total of 51,006 specimens of Drosophilidae studied. It includes data on 108 species from two subfamilies, covering 49 regions of Russia. Considering additional published sources, 188 species of Drosophilidae are currently known from Russia, with a complete species list provided. Among the most abundant species in the dataset, 10 species are represented by more than 1000 specimens: Drosophila obscura, Scaptodrosophila rufifrons, Drosophila melanogaster, Drosophila phalerata, Drosophila transversa, Drosophila kuntzei, Drosophila histrio, Drosophila testacea, Phortica semivirgo, and Drosophila immigrans. Conversely, 39 species are represented by fewer than 10 specimens in the dataset. Regarding ecological groupings, the most dominant groups are xylosaprobionts (39 species, 40.6%) and mycophages (30 species, 31.3%). Notably, in 2017, the quarantine pest Drosophila suzukii was detected in the European part of Russia. The current knowledge of the Drosophilidae fauna in Russia remains insufficient. Of the 15 regions, only one or two localities are represented in the dataset. The distribution limits and range boundaries of many species remain unknown. Moreover, the local faunas of more than half of Russia’s regions remain unexplored. Full article

Parasitoid wasps are vital for biological control, and while new species continue to be discovered, evaluating their biological characteristics is crucial for realizing their potential for pest management. Pachycrepoideus vindemiae (Rondani) (Hymenoptera: Pteromalidae) is a well-studied parasitoid of dipteran pests, while Trichomalopsis ovigastra Sureshan & Narendran (Hymenoptera: Pteromalidae) has been only morphologically described. To assess its biocontrol potential, we compared the biological traits of T. ovigastra and P. vindemiae using Drosophila melanogaster Meigen (Diptera: Drosophilidae) and Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) as hosts. T. ovigastra showed significantly higher parasitism rates, especially against B. dorsalis, where T. ovigastra achieved nearly 50% parasitism, compared to less than 0.3% by P. vindemiae. When using D. melanogaster as the host, no significant differences were observed between T. ovigastra and P. vindemiae in offspring sex ratio or adult longevity; however, T. ovigastra exhibited a shorter developmental duration and greater tolerance to temperature extremes, starvation, and desiccation. Notably, B. dorsalis has expanded its range from southern to northern China; however, no native parasitoids of this pest have been reported in the newly invaded northern regions. T. ovigastra, collected from northern orchards and capable of parasitizing B. dorsalis, thus shows promise as a biocontrol agent. These findings highlight the potential of locally occurring parasitoids, although field validation is still required. Full article

Drosophila suzukii (Matsumura) is a relevant pest affecting berries and stone fruits globally, including in the Neotropical region, where its invasion was reported about a decade ago. Despite chemical control being the main management method for D. suzukii, data on insecticide susceptibility in Neotropical D. suzukii populations are scarce. Here, we assessed the susceptibility of three field-collected Brazilian D. suzukii populations to four insecticides (i.e., deltamethrin, permethrin, spinetoram, imidacloprid) and contrasted this with a standard insecticide-susceptible population. Using the discriminating concentration (LC₉₀) from the standard susceptible population, we identified resistant populations. Synergist exposure (piperonyl butoxide, triphenyl phosphate, diethyl maleate) indicated the role of detoxification enzymes in resistance. Our results showed that deltamethrin was the most toxic, followed by spinetoram, permethrin, and imidacloprid. While all field populations were similarly susceptible to pyrethroids and spinosyns, one population from Minas Gerais (i.e., Paula Candido) had significantly lower imidacloprid susceptibility, with only 53.4 ± 5.2% mortality at 10.0 g/L (the equivalent of 10-fold the estimated imidacloprid LC₉₀). Only piperonyl butoxide increased the imidacloprid susceptibility of Paula Candido flies. Our findings indicate the occurrence of cytochrome P450 enzyme-based imidacloprid resistance in the state of Minas Gerais, which can challenge the management of D. suzukii in Brazil. Full article

Spotted wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), are invasive vinegar flies of East Asian origin that are an increasingly global threat to the small fruit industry. It is essential that new classes of eco-friendly insecticides and cost-effective strategies for SWD control are developed. Here, we describe the preparation of a strain of RNA interference (RNAi) Saccharomyces cerevisiae expressing shRNA that specifically targets the SWD RNA-binding Fox protein 1 (Rbfox1) gene. The yeast effectively silences the SWD Rbfox1 gene, resulting in significant loss of fly neural activity. Laboratory trials demonstrated that the RNAi yeast can be mixed with soda, which functions as SWD attractive targeted sugar bait (ATSB) that can be delivered in a soda bottle feeder. The ATSB, mixed with yeast that was heat-killed prior to suspension in the ATSB, resulted in 92 ± 1% mortality of SWD flies that consumed it, yet had no impact on non-target dipterans. Rbfox.687 yeast delivered in ATSB feeders may one day be a useful component of integrated SWD control programs. Full article

Trichopria drosophilae is a globally distributed pupal parasitoid that targets various species within the Drosophilidae family, including the invasive Drosophila suzukii. The mass rearing of T. drosophilae is a crucial step in ensuring their successful application for field D. suzukii control. The pupae of Drosophila melanogaster are currently used as a host for the mass rearing of T. drosophilae. After irradiation, the immune system function of Drosophila pupae was weakened, leading to an increase in the parasitism efficiency of the T. drosophilae. Our results showed that irradiated pupae had a significant impact on the parasitism rate, offspring eclosion rate, offspring number, and female body size of F1 T. drosophilae, all of which were significantly lower than those in the normal group. However, there was no significant difference in the parasitism rate, body size, offspring eclosion rate, offspring number, or offspring sex ratio between F2 T. drosophilae emerging from treated or untreated Drosophila pupae. Compared with F2, F1 had a significantly higher net reproductive rate (R₀), mean generation time (T), and doubling time (DT), while the intrinsic rate of increase (r) was significantly lower. Using irradiated D. melanogaster pupae provides an efficient method for the mass rearing of T. drosophilae and offers valuable insights into its potential effectiveness in field D. suzukii control. Full article

The article addresses the current and future potential distribution of Drosophila suzukii (Diptera: Drosophilidae), commonly known as spotted wing Drosophila (SWD). This invasive pest affects various fruit crops worldwide. Native to Southeast Asia, the species has rapidly expanded due to its high adaptability to climates and ability to infest ripe fruits. SWD occurrence data were collected from multiple databases, pseudo-absences were selected from the background area, and climatic variables were downloaded from WorldClim. The Random Forest algorithm was employed to model the current distribution and project future scenarios, categorizing environmental suitability into high, moderate, and low levels. The analysis of bioclimatic variables indicated that factors such as isothermality, maximum temperature of the warmest month, and precipitation of the driest month are the most significant for pest distribution. The results revealed high climatic suitability for the species in North America, Europe, and Asia, with projections indicating expansion under climate change scenarios in the Northern Hemisphere, including new areas in Europe and North America. Regions with higher suitability are expected to require management and monitoring strategies, particularly in vulnerable agricultural areas. Furthermore, the study underscores the importance of climatic data in predicting pest distribution and formulating effective control and mitigation policies. Full article

The overuse of synthetic pesticides has triggered resistance in insect pests and caused severe environmental impacts, emphasizing the urgent need for sustainable alternatives in Integrated Pest Management (IPM). This study aimed to biosynthesize and characterize chitosan-coated silver nanoparticles (AgChNPs) using Galega officinalis leaf extract and evaluate their insecticidal effects against Drosophila suzukii (Diptera: Drosophilidae), a key pest of fruit crops worldwide. The biosynthesized AgChNPs (257.2 nm) were polydisperse, crystalline, and stable, as confirmed by UV-vis spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). AgChNPs exhibited strong toxicity across multiple developmental stages. Combined larvicidal and pupicidal activity reached 48.3% and 73.3% at 500 and 1000 ppm, respectively, significantly affecting immature stages. As a consequence, adult emergence declined to 46.7%, 51.7%, and 26.7% at 250, 500, and 1000 ppm. Among emerged adults, 71.7% displayed sublethal effects, with 62.8% showing morphological malformations (deformed wings, dehydration) and 37.2% presenting cuticle demelanization. Adulticidal bioassays revealed progressive mortality over 48 h, with 96% mortality at 1000 ppm. Overall, AgChNPs caused acute and chronic toxicity, reduced adult emergence, and induced severe morphological alterations, demonstrating their potential as a sustainable nanotechnological tool for effective pest control within IPM programs. Full article

Background: Attractive Toxic Sugar Baits (ATSBs) are an innovative vector control strategy based on the “attract-and-kill” principle. The core of ATSBs lies in the preparation of attractive and toxic baits through the mixing and proportioning of luring and active ingredients. Although previous studies have investigated the effects of ATSBs on mosquitoes, significant challenges remain for broader field application. Methods: This study evaluated five fruit juices as ATSBs for mosquitoes, focusing on feeding preferences. Preservative concentrations were assessed by measuring antimicrobial activity over time. Two commercial traps were tested for mosquito entry rates. The optimal insecticide species and concentration were determined based on mortality rates. An optimized ATSBs system was developed and tested under a semi-field cage. Statistical analysis was performed using GraphPad Prism. Results: Within 24 h, apple juice-based ATSBs had the highest attractant index for Culex quinquefasciatus and Anopheles sinensis, while a pear juice-based ATSB was most effective for Aedes albopictus. A 0.1% preservative concentration best maintained juice stability. The LC50 values of dinotefuran-based ATSBs for Cx. quinquefasciatus, Ae. albopictus, and An. sinensis were 1.18 × 10⁻³, 4.06 × 10⁻⁴, and 5.20 × 10⁻⁵ g/L, respectively. The Spodoptera frugiperda trap outperformed the Drosophilidae trap. Simulated semi-field cage tests showed 48 h mortality rates of 86.00% for Cx. quinquefasciatus and 95.67% for Ae. albopictus. Conclusion: This study optimized an ATSB system by screening various fruit juices, preservative concentrations, insecticides, and trap devices. The system’s efficacy in mosquito control was evaluated under a semi-field cage. These findings provide a strong foundation for the future application and refinement of ATSB-based mosquito control strategies. Full article

Drosophila suzukii is a pest affecting a wide range of host plants, causing severe damage to small fruits, berries, and grapes. This study analyzed environmental factors influencing its population dynamics in regions where temperature is not a limiting factor. Data were collected in the spring–summer seasons of 2018 and 2019 across three vineyards in northwestern Portugal, examining the relationship between captured D. suzukii females, climatic variables, vine phenological stages, and ecological infrastructures. A stepwise linear model and Pearson correlation matrix were used. In 2020, a winter study was conducted in nine vineyards, focusing on landscape composition and its effect on D. suzukii populations. An ecological infrastructure index was created and correlated with captures data. Results show that vine phenological stages and nearby ecological infrastructures significantly affect population dynamics in spring and summer. Vineyards surrounded by complex landscapes, especially with wild hosts, supported higher D. suzukii populations during winter. These findings highlight the importance of ecological infrastructures in managing D. suzukii populations year-round and suggest their consideration in pest control strategies. Full article

Drosophila suzukii (Diptera: Drosophilidae), spotted-wing drosophila, poses a significant threat to soft-skinned fruit crops in the Americas, Europe, Africa, and Oceania, as well as in Asia. The application of chemical insecticides is the primary control strategy for D. suzukii; however, resistance has developed with the indiscriminate use of chemical insecticides. Essential oils, considered potential alternatives to pesticidal strategies, exhibit potent toxic and sublethal behavioral effects against numerous pests, including D. suzukii. Clary sage oil repels a variety of agricultural and household pests; however, whether it has a repellent effect against D. suzukii remains unknown. Here, we found that clary sage oil exhibited dose-dependent repellency against D. suzukii adults in a T-maze assay, a two-choice assay and a two-choice attraction assay. Also, clary sage oil showed a significant repellent effect against D. suzukii larvae. Next, we explored the chemical constituents of clary sage oil by GC-MS and identified two major constituents, linalyl acetate (40.03%) and linalool (23.02%). Furthermore, the behavioral assays of linalyl acetate and linalool showed that both compounds conferred comparable repellency against D. suzukii adults and larvae. Finally, we found clary sage oil, linalyl acetate, and linalool elicited EAG responses in D. suzukii, especially clary sage oil, suggesting the repellency was mediated by the olfactory system. These findings indicate that D. suzukii shows olfactory-based behavioral avoidance of clary sage oil, linalyl acetate, and linalool. Clary sage oil and its major constituents may be possible alternatives in the management of D. suzukii. Full article