Journal of Applied Entomology最新文献

Leatherjackets (Tipula spp.) are soil-dwelling pests associated with agriculture. Land management decisions made at farm scale can have subsequent effects on their populations. Between 1980 and 2020, surveys were conducted across Scotland to collect field histories and larval population data from grassland farms. To assess the impact of management and bioclimatic factors on leatherjacket occurrence over time, this study investigated data from fields continuously sampled between 2009 and 2018. We utilized a Generalized Linear Mixed-Effect Model on a dataset of 61 fields on 19 farms. Results indicated three significant factors affecting larval populations; field size, grazing type and application of insecticides or herbicides (referred to collectively as pesticides). Larval populations were significantly lower in fields that were larger in size and under sheep grazing, compared to no grazing. Pesticide application also caused a significant reduction in larval populations. Management variables were amalgamated to create a Management Intensity Index, revealing significantly increased larval populations under low-management systems. These results, coupled with significant effects of bioclimatic variables, pinpoint predictive signals for high infestations and potential routes for control strategies.

Click beetle larvae have been observed to cause crop damage in various regions worldwide; however, accurate prediction of plant damage is hindered by their subterranean life cycle and the associated challenges in sampling. Melanotus senilis, a beetle belonging to the subfamily Elaterinae (tribe Melanotini) within the family Elateridae, is a destructive agricultural pest that harms maize, hops, and ginger. Our study presents novel evidence indicating the attraction of M. senilis larvae to Citrus natsudaidai (Japanese name “Natsumikan” or “Natsudaidai”). Through a field experiment involving different citrus fruits, namely natsumikan, oranges, and grapefruits, we found that C. natsudaidai attracted the highest number of M. senilis larvae. Furthermore, in a separate experiment in which C. natsudaidai and potatoes were placed in the field, C. natsudaidai significantly outperformed potatoes in attracting M. senilis larvae. These findings suggest that C. natsudaidai fruit placed on the soil surface attracts M. senilis larvae. C. natsudaidai fruits used in this study were sourced from those that remained unharvested until August. Therefore, it is possible that the C. natsudaidai fruits used for comparison were more mature than the citrus fruits used in this study. It is possible that the ripening of C. natsudaidai may have led to changes in CO₂ and ethylene emissions, potentially attracting a greater number of M. senilis larvae. Further research is required to explore these aspects in detail.

Plants have developed chemical defence strategies which can either be triggered in response to herbivory or by the exogenous application of phytohormones, such as methyl jasmonate (MeJa). Tuta absoluta is the main pest associated with tomatoes worldwide. However, studies on the impact of plant hormones on this system are still scarce. This study aimed to evaluate the chemotactic responses and oviposition of T. absoluta towards tomato plants induced by MeJa and herbivory injuries. We conducted dual-choice olfactometry bioassays evaluating the response of virgin T. absoluta males and females exposed to plants with conspecifics (eggs and caterpillars) and sprayed with MeJa (0.5 mM) at 24, 48, 72 and 96 h after the treatments. We also evaluated the oviposition preference of mated T. absoluta with the chance of choosing plants exposed to water, herbivory and three phytohormone concentrations (0.1, 0.5 and 2.5 mM). The males were mostly responsive to plants with conspecifics, while the females preferred intact plants over those sprayed with MeJa and with the presence of eggs. Furthermore, plants with MeJa (0.5 and 2.5 mM) and injured by conspecifics had less oviposition by T. absoluta. The results show that spraying MeJa on tomato plants is a potential tool for managing and controlling the tomato moth.

Spotted-wing drosophila (SWD), Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae) cause yield losses and important economic impacts in fruits with thin epicarp. In the present study, the combination of powdered sulphur and predators/parasitoids for the control of SWD was analysed. First, the interaction of powered sulphur with Anthocoris nemoralis (Hemiptera: Anthocoridae) on infested strawberry fruits and Trichropia drosophilae (Hymenoptera: Diapriidae) on SWD pupae was evaluated. Second, exposure of predators/parasitoids to strawberry leaves with powdered sulphur was also assessed. Additionally, sublethal effects of powdered sulphur on T. drosophilae parasitism were examined. The results show powdered sulphur did not interfere with the activity of A. nemoralis and caused a significant reduction in fruit infestation. In contrast, sulphur affected the activity of T. drosophilae, reducing parasitism when the two agents were combined. Direct exposure to powdered sulphur did not cause significant mortality of A. nemoralis and T. drosophilae. Finally, previous exposure to sulphur did not affect T. drosophilae in terms of parasitism rates and sex ratio. Based on the results obtained herein, sulphur and T. drosophilae impacts on different stages of SWD when they are applied separately. However, the effects of sulphur on T. drosophilae should be taken into account in combination control strategies of SWD.

Fruit fly pestiferous species within the genus Anastrepha Schiner (Diptera: Tephritidae) affect fruit growing in northeastern Mexico, particularly citrus and mango production. Little is known about the population fluctuation of these pests in protected natural areas adjacent to agricultural environments. This study aimed to compare and analyse the temporal profiles of adult populations of Anastrepha pest species inhabiting agricultural zones and a protected natural area. Six years of adult capture data of Anastrepha ludens (Loew), A. obliqua (Macquart), A. striata Schiner and A. serpentina (Wiedemann) were compared and analysed between commercial orchards and fruit tree areas located in the buffer zone of the biosphere reserve “El Cielo”. The analyses were carried out for each of two triennial periods (2008–2010 and 2019–2021). Temporal patterns of the pest populations were characterized, and generalized linear mixed models were used for data analysis. All locations registered the four species, although Anastrepha ludens and A. obliqua represented the highest number of adult captures. Populations of pest species of Anastrepha showed similar fluctuation patterns throughout the year regardless of the location. However, significant differences in the population size were noted between the “El Cielo” reserve and commercial areas. The “El Cielo” reserve and its surroundings captured the highest population levels of the four species. Persistent populations of A. striata and A. serpentina were related to the area under ecological protection. The “El Cielo” reserve is a shelter for the pest species of Anastrepha, which are mainly linked to backyard hosts. We discuss the importance of these findings in the context of an Area-Wide Integrated Pest Management approach and of studying fruit flies' quarantine pests in Mexico's neotropical limits. Practical implications in designing specific phytosanitary measures to suppress or control pest populations are addressed.

Bionomics of an insect and metabolic flux of the host plant are important tools to decipher the status of plant resistance against insect species. This study illuminates vital information on aphid-induced levels of phytochemicals in the siliquae of Brassica juncea cultivars and their effect on host selection and population growth parameters of Lipaphis erysimi. The current study unveiled that the siliquae preference, intrinsic rate of increase (r), finite rate of increase (λ), gross reproductive rate (GRR) and net reproductive rate (R₀) were significantly lower on Pusa Mustard 27, DRMR 150-35, RLC 3, NRCHB 101, Pusa Mustard 26 and Pusa Mustard 25. However, the mean generation time (T) and doubling time (DT) of L. erysimi were significantly longer (p < 0.001) in these genotypes. These cultivars were also found with elevated levels of aphid-induced phytochemicals and their associated enzymes, except in a few cases. Total antioxidants, ferric ion reducing antioxidant power, chlorophyll A, total chlorophyll, ascorbate oxidase (AO), catalase, phenylalanine ammonia lyase (PAL) and myrosinase were found to contribute 49.18–85.30% variation for siliquae preference and bionomics of L. erysimi on the test B. juncea cultivars. The study revealed that phenols, antioxidants, chlorophyll A, chlorophyll B, total carotenoids, AO, ascorbate peroxidase, PAL, tyrosine ammonia lyase and myrosinase had significant and negative direct consequences on the siliquae preference and bionomics, thus can be exploited as biochemical markers to identify sources of resistance against L. erysimi. Furthermore, DRMR 150-35, NRCHB 101, RLC 3, Pusa mustard 26, RH 749 and Pusa Mustard 27 were found with greater aphid-induced defence phytochemicals and detrimental effects on the host selection and bionomics of L. erysimi, thus can be deployed in Brassica improvement program.

The functional and numerical response and the potential for mutual interference are key components in the selection of parasitoids for biological control. In this study, functional and numerical responses of Goniozus legneri to different densities of fifth instar Cydia pomonella larvae and mutual interference of this parasitoid were studied under laboratory conditions. Logistic regression was used to find the type of functional response and the result was type II. The attack rate, handling time, the parasitoid searching efficiency and the maximum host mortality rate were estimated by fitting the Holling model to the data. The numerical response of the parasitoid did not vary based on the availability of codling moth larvae. The negative value of the interference coefficient (−0.228) in the mutual interference analysis showed an inverse relationship between parasitoid density and per capita searching efficiency. This suggests that when the density of G. legneri and C. pomonella larvae is equivalent, the parasitoid proves to be more effective in pest control. The findings of this study contribute to increasing the knowledge of G. legneri and its potential as a biocontrol agent.

Deploying resistant wheat cultivars is the most economical and environment-friendly strategy to manage the devastating effects of the dipteran pest, Hessian fly (Hf; Mayetiola destructor). Currently, 37 Hf resistance genes have been identified to combat the 18 Hf genotypes documented so far. However, the Hf populations adapt rapidly to overcome the newly deployed resistance genes within a few years of release resulting in development of virulent Hf biotypes and breakdown of plant resistance. Identification of new and novel sources of resistance offers breeders additional resources that can be included in the breeding programmes to develop elite Hf-resistant cultivars. In the current study, we screened 374 wheat (tetraploid and hexaploid) accessions originating from different regions of the United States and identified three tetraploid (Triticum turgidum) pasta wheat lines, one originating from North Dakota (PI 639869) and two from Minnesota (PI 352398 and CItr 15710) exhibiting ≥95% resistance to Hf biotype L at 20°C. Further, the wheat cultivar PI 352398 showed 100% resistance to six additional Hf genotypes including biotypes B, C, D, O, GP and vH13. The lines PI 639869 and CItr 15710 also showed >70% resistance with most biotypes, except against biotype GP with the former and biotype B with the latter. Interestingly, a few plants from these two cultivars exhibited putative tolerance to these biotypes where the plants showed normal growth but harboured white, live larvae and showed cell permeability that was intermediate in levels between Hf-infested resistant and susceptible wheat. Additionally, since the increase in environmental temperatures to 25–30°C also negatively impacts Hf resistance, the three T. turgidum (PI 639869, PI 352398 and CItr 15710) cultivars were evaluated for Hf resistance at 30°C. None of the wheat cultivars were resistant to Hf biotype L at 30°C indicating a temperature-dependent breakdown of resistance and are therefore not suitable for geographical regions with higher environmental temperatures. Taken together, these three wheat lines represent additional sources of Hf resistance that can be leveraged by breeders for developing durable elite lines.

To understand the effect of diet on gut bacteria of Cnaphalocrocis medinalis (rice leaf folder, RLF), we compared the composition and diversity of gut bacterial community in C. medinalis larvae collected from three different rice variety fields of Minghui 82 (RLF1), Youngyong 15 (RLF2) and Minghui 2155 (RLF3), using culture-independent PCR (V3 variable region)-denaturing gradient gel electrophoresis (PCR-DGGE) methods and hypervariable region (V4) of 16S rRNA sequenced by Illumina HiSeq platform. The DGGE result showed that the bacteria genera Asaia, Bacillus, Stenotrophomonas, Achromobacter and Serratia coexisted in the guts of RLF1, RLF2 and RLF3, while Cedecea, Burkholderia and Acinetobacter coexisted in the guts of RLF2 and RLF3. However, only the genus Enterococcus existed in the guts of RLF1, and Pantoea, Wolbachia and Tumebacillus in RLF3 larvae. A total of 25 bacterial phyla, 48 classes, 127 orders, 223 families, and 406 genera were identified when using 16s RNA sequencing, with 35 genera coexisted in RLF1, RLF2 and RLF3 larval guts, while 83, 36, 141 unique genera existed in RLF1, RLF2 and RLF3, respectively. The indices of ACE and Shannon were not significantly different among RLF1, RLF2 and RLF3. The dominant bacterial taxa were Proteobacteria, Bacteroidetes and Firmicutes at the phylum level, and Acinetobacter and Wolbachia at the genus level. The relative genus abundance for the genera with relative abundance (≥0.01) was significantly different among RLF1, RLF2 and RLF3. The findings indicated that different rice varieties had significant effects on the relative abundance of gut bacteria in RLF, which could provide new insights into the relationship between insect gut bacteria and their associated host plants.

Metcalfa pruinosa is a highly polyphagous, invasive insect in Europe with the capability of transferring phytoplasma. In the present study, we aim to identify volatile organic compounds that may act as semiochemicals for M. pruinosa. Using a dynamic volatile collection system, volatile organic compounds were collected from Ailanthus altissima, Aristolochia clematitis and Tagetes patula. Compounds were identified using gas chromatography–mass spectrometry. We also tested the electrophysiological responses of M. pruinosa to the collected volatile organic compounds using gas chromatography-electroantennographic detection. In total, 77 volatile organic compounds were identified, and 29 compounds elicited an electroantennographic response. We analysed responses to volatile organic compounds extracted from Tagetes patula to compare antennal sensitivity between developmental stages and sexes. No differences were found in responders' number or response amplitude between males and females or adults and nymphs for any volatile. Based on the detected compounds, M. pruinosa adult females and males seem to have similar ecological needs in the host habitat. However, when we compared the response amplitudes among compounds, significant differences were found. These differences suggest that (E)-4,8-dimethyl-nonatriene, methyl salicylate, and piperitone could have an important role in M. pruinosa's behaviour. This is the first contribution to M. pruinosa olfaction profile providing a base for future semiochemical-based pest control tactics.