Journal of Applied Entomology最新文献

Blueberry cultivation requires insect-mediated pollination for optimal fruit formation. Studies have shown that improving the efficiency of pollen exchange during flowering increases both the quantity and quality of fruit. Blueberry flowers have a unique anther structure that facilitates pollen release through a specialised interaction called ‘buzz pollination’, which is performed by wild bee species rather than Apis mellifera. The study aims to assess the effects of pollination management, weed management, and landscape heterogeneity on pollinator communities, and their interaction with the crop and blueberry fruit set. Nine blueberry plots were studied to investigate the influence of including Bombus pauloensis hives, the presence of inter-row vegetation, and landscape heterogeneity on pollinator abundance, richness, visitation rate, and fruit production. Generalised linear mixed models (GLMM) were used to analyse the relationship between these factors. No significant differences in fruit formation were found between plots receiving pollination services from Apis mellifera and those with a combination of A. mellifera + B. pauloensis hives. However, inter-row vegetation had a positive effect on pollinator abundance and visitation rate to blueberry flowers. The increase in cultivated areas had a negative effect on the visitation rate of both managed and native pollinators. Conversely, more diverse landscapes had a negative and significant effect on A. mellifera abundance within the plots. These findings suggest the importance of implementing wild pollinator-friendly management practices, carefully assessing honeybee densities, and managing resources at both local and landscape scales to enhance bee visitation and blueberry fruit production.

The contribution of dipterans to pollination in tropical communities has been scarcely studied. Although some studies have evaluated dipteran pollination in crops and wild species, limited attention has been paid to their role in pollination networks. In particular, their role in pollen transport has been neglected. Integrating their role as floral visitors and their importance in pollen transport through interaction networks may help reveal their importance in pollination in tropical co-flowering communities. We constructed visitation and pollen transport networks from the analysis of pollen carried on dipteran bodies in two tropical coastal communities to test the prediction that pollen transport networks would reveal fewer but more specialised interactions than visitation networks. We estimated parameters describing the network topology and the main estimators of the roles of each species. We recorded 1372 floral visits and counted 46,001 pollen grains. Our results showed that the visitation and pollen transport networks exhibited similar pollination network structures (e.g., nestedness, specialisation, and modularity). However, the pollen transport network suggested a higher level of specialisation between dipterans and plants in both communities. In addition, the networks' modular structure suggested contrasting species grouping according to network type. Moreover, most dipterans were classified as peripheral species in pollen transport networks, suggesting high within-module interactions. Although some estimators of dipteran role through visitation (nestedness contribution and resource range) can be used as indicators of pollen transport, we found that pollen transport is a better descriptor of dipteran specialisation or the role of the species in the modular structure of the network. This work is the first to explore the importance of dipterans using visitation and pollen transport data in the tropics. Overall, our results suggest that a better understanding of the dipteran's importance in pollination networks is necessary to add information on their role in pollen transport.

Severe leafhopper pests infesting fruit trees (apricot, grape, peach, persimmon and plum) in South Korea were investigated. DNA barcoding using mitochondrial cytochrome c oxidase (COI) sequences identified four Typhlocybinae species: Arboridia kakogawana and Arboridia maculifrons on grape, Singapora shinshana on Prunus trees and Zorka sp. on persimmon, spanning both nymphal and adult life stages. Notably, DNA barcoding revealed phylogenetically relevant colour variation among adult specimens of the grape pest, A. kakogawana. This study presents, for the first time, live nymphal and adult photographs alongside neighbour-joining trees, host plant associations and updated DNA barcode sequences for these Korean leafhoppers, which have not previously been included in global datasets.

Entomopathogenic nematodes (EPNs) of the genera Heterorhabditis and Steinernema are widely used as biological control agents (BCAs) against agricultural insect pests. Recently, nematodes from the genus Oscheius have shown potential as candidates for biological control agents. In this study, two nematode populations from the agricultural fields in Bukidnon, Philippines, were isolated using the traditional insect soil baiting technique with superworm (Zophobas morio). Through morphological, morphometrical, and molecular analyses, these nematodes, labelled as BRT2 and CSS4, were identified as Oscheius colombianus, the country's first record of the species. Preliminary laboratory assays were conducted to evaluate the efficacy of the isolated nematodes against Z. morio larvae. The results showed that the isolate BRT2 exhibited higher efficacy than the isolate CSS4. Isolate BRT2 was tested against different developmental stages of Spodoptera litura and effectively controlled all stages. The fourth and fifth instar larvae showed the highest susceptibility within 72–96 h post-inoculation at various test concentrations (500, 300 and 100 IJs/larvae). However, 2-day-old pupae had the lowest mortality rate among all treatments, with the commercially available Steinernema siamkayai Thai strain (SST1) serving as the standard control. This study highlights the potential of locally isolated nematodes as biocontrol agents for combating different stages of S. litura. The findings contribute to the growing research on EPNs and their applications in agricultural pest management.

Ephestia elutella (Hübner) (Lepidoptera: Pyralidae), an omnivorous pest with a wide range of hosts, is responsible for the damage and loss of many stored commodities. However, the parasitoid wasp Habrobracon hebetor (Say) (Hymenoptera: Braconidae) utilises 5th instars of E. elutella larvae to breed. In order to support the large-scale production of E. elutella for research and parasitoid rearing, we explored the effects of diet (artificial diet and tobacco) on the mortality, developmental duration, adult longevity, fecundity, and population parameters of E. elutella reared at 19°C, 22°C, 25°C, 28°C, and 31°C using age-stage, two-sex life tables. Increasing the temperature from 19°C to 31°C significantly affected the stage-specific mortality, reproductive parameters, and population parameters of E. elutella. Specifically, both developmental duration and adult longevity decreased with increasing temperature. For both diets, pre-adult mortality was lowest at 25°C but was lower overall in populations fed an artificial diet. The developmental duration, adult longevity, and mean generation time (T) were significantly lower in populations fed an artificial diet, whereas the intrinsic rate of increase (r) and finite rate of increase (λ) were significantly lower in populations fed tobacco leaves. Temperature appears to have a significant effect on the development and reproduction of E. elutella, and a combination of 25°C and artificial diet may be the most conducive to large-scale breeding. This study provides a theoretical basis for the mass rearing of E. elutella to support pest control applications in tobacco warehouses.

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a serious insect pest of tomato crops. Our previous study revealed that the tomato varieties JinLingHongYu and ShiTouDaFen are resistant and susceptible to MED B. tabaci, respectively. In this study, we focused on determining the transcriptional response of these two tomato varieties before and after infestation with B. tabaci using Illumina sequencing. A total of 629, 859, 512 clear reads were mapped to the tomato reference genome. According to the filtering threshold (log2 ratio ≥ 2, false discovery rate (FDR) ≤ 0.05), 727 differentially expressed genes (379 upregulated and 348 downregulated) were identified in the susceptible tomato variety before and after infestation, respectively, while 1060 (537 upregulated and 523 downregulated) were identified in the resistant tomato variety. The Unigenes might be involved in the tomato variety resistance genes to B. tabaci, such as receptor-like kinase, the cell-wall-modifying enzymes of the xyloglucan endotransglucosylase/hydrolase family, expansin, tryptophan-arginine tyrosine transcription factor, cytochrome P450, GDSL esterase/lipase, Nucleotide-binding adaptor shared by Apaf1, R proteins and CED-4 (NB-ARC) and F-box. To verify the results of the transcriptome analysis, 18 genes were randomly chosen and subjected to RT–qPCR. The RT–qPCR results were the same as those of the transcriptome analysis. The present results provide important information on B. tabaci resistance mechanisms in tomato varieties that will be useful for further studies of the molecular mechanisms of this resistance and for breeding new pest-resistant varieties.

Black truffle, Tuber melanosporum Vittad., production is increasing due to an improvement in cultivation management and to the demand for this highly appreciated fungus. However, this intensification of truffle cultivation has led to the appearance of problems related to pest incidence. Specifically, the truffle beetle, Leiodes cinnamomeus (Panzer, 1793) (Coleoptera: Leiodidae), causes significant losses in black truffle marketability. However, its biology is still poorly known, and no effective agro-ecological methods exist to mitigate its damage to the truffles. This study aimed at assessing the population dynamics of L. cinnamomeus over four seasons (2019–2023) in an orchard located in NE Spain and relating these dynamics to weather variables and damage to truffle fruit bodies. Moreover, we described the diversity of arthropods captured in the traps in search of potential natural enemies of this beetle. The maximum population peak was observed in November, except for a single season in which it occurred in December. Moreover, the sex ratio was balanced (0.54 on average), but it varied over the growing season and among years. Significant and positive relationships of the population density of truffle beetles with air temperature and relative humidity were observed. The number of beetles per trap and day was strongly linked to heat accumulation. Finally, the Carabid Percus (Pseudopercus) patruelis (L. Daufour, 1820) was identified as a natural enemy of L. cinnamomeus. These results could be used in the future for monitoring and predicting truffle beetle populations.