Journal of Applied Entomology最新文献

Insect gut microbes represent a rich source of enzymes and metabolic pathways that can be harnessed to advance renewable energy production. This review explores the potential of insect gut microbiota in the context of biomass degradation and biofuel production. Insects, particularly wood-feeding species like termites and beetles, harbour complex microbial communities in their guts that efficiently break down lignocellulosic materials into simple sugars. These sugars can then be fermented into biofuels such as ethanol and methane. Recent research has focused on identifying key microbial species and enzymes involved in this process, as well as on engineering these microbes to enhance their efficiency and substrate specificity. Additionally, the ecological roles of these microbes in insect digestion and their potential for biotechnological applications beyond biofuel production are discussed. Overall, understanding and harnessing insect gut microbes holds great promise for advancing sustainable and renewable energy solutions.

The attractive effect of dung on coprophagous beetle communities and their role in dung degradation are well-known phenomena. However, little research has been conducted on the recruitment capacity of this substrate for other arthropods, especially those inhabiting the soil. With the aim of beginning to recognize general patterns in these relationships, the influence of the structure and origin of dung from invasive exotic mammals on the recruitment of microarthropods was investigated in two meadows within Nahuel Huapi National Park in southwestern Argentina. Abundance, richness and diversity of microarthropod communities collected on invasive mammal dung were studied. A total of 2478 microarthropods were collected and 52 species were identified. Recruitment of microarthropods on dung of two invasive coprophagic herbivores, the rabbit, Oryctolagus cuniculus and the hare, Lepus europaeus, were compared with two invasive non-coprophagic mammals, one herbivorous, the red deer, Cervus elaphus and one omnivorous, the wild boar, Sus scrofa. Pellets of S. scrofa showed the highest microarthropod abundance and richness while diversity was greatest on pellets of C. elaphus. Pygmephorid and oribatid mites and springtails were the most abundant. Liposcelis psocopterans and oribatid mites were more abundant on S. scrofa dung. Low similarity was observed when comparing dung of invasive mammals from different sites revealing spatial variability regarding species composition. Based on its more diverse diet, we conclude that S. scrofa dung exerts a strong influence on microarthropod communities by recruiting a greater number of individuals and species than the dung of the remaining invasive mammals.

Dictyophora rubrovolvata and Pleurotus ostreatus are economically important mushrooms in China. Bradysia minpleuroti Yang et Zhang and Coboldia fuscipes (Meigen, 1830) are important mushroom flies that damage the two mushrooms. In this study, we used the age-stage, two-sex life table method to assess the fitness of B. minpleuroti and C. fuscipes when they were respectively fed on D. rubrovolvata and P. ostreatus. Our results showed that the first (2.39 days) and second (1.41 days) instar larvae, pupa (2.87 days) and total longevity (18.19 days) of B. minpleuroti were shorter when fed on P. ostreatus than fed on D. rubrovolvata (3.46, 1.86, 3.10 and 20.19 days). B. minpleuroti had similar fecundity when fed on the two edible mushrooms. B. minpleuroti had higher values of net reproductive rate (R₀, 87.73), intrinsic rate of increase (r, 0.2604 day^-1), and finite rate of increase (λ, 1.2974 day^-1) and shorter mean generation time (T, 17.19 days) when fed on P. ostreatus than fed on D. rubrovalvata (26.96, 0.1659 day^-1, 1.1805 day^-1, 19.85 days). The developmental period of larvae and pupa stages of C. fuscipes were significantly different fed on the two edible mushrooms. Female fecundity, total longevity, R₀, r, λ and T of C. fuscipes were not significantly different between the two edible mushrooms. We found that fitness of B. minpleuroti larvae had higher fitness when fed on P. ostreatus than fed on D. rubrovolvata. However, there was no significant difference in the fitness of C. fuscipes larvae when fed on the two edible mushrooms. This study has provided valuable data and insights by delving into the adaptability of two significant pests on two edible mushrooms, thereby facilitating the development of more effective pest management strategies and contributing to the advancement of the mushroom industry. For instance, it provides guidance on the appropriate timing for preventive measures and treatment.

Caloptilia roscipennella (Hübner, 1796) is a leaf-mining moth native to Central and Southern Europe. In this publication, we provide the first report of the occurrence of Caloptilia roscipennella in India. The identification was performed using an integrative approach, combining molecular (barcoding, COI) and morphological analysis (forewing pattern). In 2020, the larvae were initially found scraping in the silvery-white mine and later feeding in folded or rolled leaves of the common walnut Juglans regia L. In the subsequent years, the species was found only in the same places. Two generations were recorded per year (May–June and August–September) and leaf miners overwintered as adults and reappeared in the early spring. Damage ranging from 15% to 20% was observed on the leaves of J. regia. Further efforts related to C. roscipennella should concentrate on evaluating its geographic distribution and its impact on walnut trees. Several species of parasitoids were reared from infested mines, with specimens belonging to the genus Chrysocharis Förster, 1856 (Hymenoptera: Eulophidae) and Itoplectis maculator (Fabricius, 1775) (Hymenoptera: Ichneumonidae). These species provided excellent control of leaf miner larvae, and out of 10 larvae, seven were found parasitized by the parasitoids and higher numbers of specimens were found with relative higher frequencies.

Many studies have examined the gene expression of baculoviruses during host infection by infecting cultured insect host cells; however, only a few have attempted to characterize the interaction between baculoviruses and insect larvae, which more accurately models the virus-insect relationship. The greatest challenge in assessing gene expression profiles in vivo in the larval gut is the lack of infection synchronization compared to cultured cells. Working with bertha armyworm, Mamestra configurata, larvae infected with the baculovirus Mamestra configurata nucleopolyhedrovirus-A (MacoNPV-A), viral gene expression was measured using droplet-digital PCR, showing that the rate of infection in individual insects varies extremely widely. Subsequent RNA-Seq of individual guts revealed that gene expression patterns were consistent in individuals with similar levels of viral gene expression. Therefore, the best approach for analysing baculovirus gene expression in vivo is to use the expression of an early viral gene as a means to select individuals that are closely matched in infection progress to produce the most synchronized infection cohorts for measuring gene expression profiles. In this way, a profile of gene expression was identified very early in infection that would have been masked by the activity of a few very robustly infected individuals present in sample pools made up of multiple individuals.

Bees can be exposed to pesticides when visiting crops or plants in adjacent areas affected by spray drift. Among pesticide categories, fungicides tend to be considered relatively safe, though they also can negatively affect pollinators. Most evidence of damage by fungicides to bees comes from laboratory tests; there is little information concerning contamination levels in the field. We examined exposure of honey bees (Apis mellifera L.) (Hymenoptera: Apidae) and a common Brazilian native species of social stingless bees (Scaptotrigona postica Latreille; Hymenoptera: Apidae), which is about a third the size of a honey bee, to a commercial fungicide (Fox Xpro), with three active ingredients (trifloxystrobin, bixafen, and prothioconazole), applied to crops they often visit according to label directions. A spraying apparatus mounted on tracks in a laboratory spray room was used to simulate field conditions. Soybean and cotton plants grown in pots were transferred to the spray room when the plants were in flower. Anaesthetized bees were attached with insect pins at the top and middle of the plants, on leaves and flowers. The fungicide was applied using fine or coarse droplets. The amounts of the individual active ingredients absorbed by bees were then quantified. Concentrations of trifloxystrobin were highest in both honey bees and stingless bees, followed by bixafen, and then prothioconazole, which was detected in the bees at much lower levels. Overall, bees at the top of the plants and those sprayed with fine droplets absorbed more pesticide. As a function of body mass, the stingless bees were more heavily contaminated than the larger honey bees. Tests using spraying systems that simulate field conditions can better estimate the actual doses that contaminate bees to help determine the impact of fungicides and other pesticides applied to crops.

A new aphid species infesting apricots (Prunus armeniaca L.) was identified for the first time in 2016 in Europe. The invasive aphid was assigned to the species Myzus mumecola (Matsumura, 1917). The species is native to India and East Asia, and it was found to be highly invasive and is currently spreading throughout Europe. Records were confirmed for Italy, Hungary, Serbia, and Germany. For a phylogenetic analysis, wingless (apterae) adults were sampled in spring 2022 in Italy, as well as in Austria and Germany in spring 2023. Our study reports the first record of M. mumecola for Austria. In all three countries, the new pest caused heavy infestations overall in organically managed apricot orchards. Aphids were identified morphologically based on external characteristics, and damages were compared to those reported in the literature. COI and 12S barcoding analyses for aphid samples from Italy, Germany, and Austria were performed to attain a molecular characterization of sampled specimens and to confirm the morphological identification. Only a few COI sequences of M. mumecola were present in NCBI GenBank or BOLD Systems, and no sequences were available for 12S. Therefore, the results provide a deeper insight into the phylogeny of this spreading pest insect. The results of the COI barcoding showed no differences between the sampled populations and other M. mumecola populations from Europe and Japan, while reports from China showed significant differences. All 12S sequences showed no variability between populations from Austria, Germany, and Italy. A phylogenetic analysis of COI and 12S sequences with sequences from other aphid species from NCBI GenBank or sampled in Italy revealed a close relationship of this species with the damson-hope aphid, Phorodon humuli.

Reproductive allocation is often balanced between the quantity and quality of offspring. Ecological stresses, like exposure to predators, can cause organisms to shift their allocations along this continuum. While the consequences of such plastic shifts for offspring performance are often untested, they are critical to understanding the potential long-term benefits of manipulating predation risk as an agricultural pest management technique. Predation risk induces reductions in egg production and increases in nutritional condition due to maternal provisioning in Colorado potato beetles (Leptinotarsa decemlineata, CPB). Here, we tested whether reductions in density or increases in offspring condition, which may increase per-capita larval survival, can compensate for the reduction in total egg production, especially when offspring are exposed to predators. In two field trials, we manipulated density and condition of larval CPB and measured survival through development to adulthood in field cages with and without predaceous stink bugs (Podisus maculiventris). As expected, cages with the higher initial larval densities had more larvae and adults surviving in the treatments without predators – about 30%–50% survival across densities. When predators were present, this relationship did not hold because of density-dependent predation. Larval condition interacted with density and impacted larval survival in both trials albeit in different ways. In trial 1, unprovisioned beetles had higher survival at the higher densities; in trial 2, provisioned beetles had higher survival across densities. Synthesis and Applications: Overall, our test of the effects of predation risk via manipulations of larval density and condition revealed few net compensatory benefits to the prey of reduced density and higher condition. Benefits to the prey of shifts in allocation from the quantity to quality of offspring may depend on factors that influence the strength of density dependence, including predation intensity. Our results suggest a new strategy of taking advantage of the reductions in prey density due to non-consumptive effects of predators as a pest management approach to protect plants.

Pest attack is an important biotic threat to sorghum productivity, and one of the main insect pests of grain sorghum is sugarcane borer (SCB) Diatraea saccharalis. Despite the importance of this insect species, little is known about the relationship between SCB infestation and reduction in sorghum grain yield, as well as on the gain threshold and economic injury level for decision making of pest control. This study evaluated the influence of SCB infestation on plant performance and grain production in three commercial grain sorghum hybrids. Hybrids AG1090, BRS 373, and DKB 590 were planted in three crop seasons in Sete Lagoas, Brazil, and six treatments were assessed in the experiments, consisting of three grain sorghum hybrids with and without the insecticide chlorantraniliprole at 52.5 g a.i. ha⁻¹ under SCB natural infestation. The parameters evaluated on sorghum plants were the length of tunnels, plant height, length and weight of panicles, stem borer injury, and grain yield. The infestation of SCB was higher when sorghum plants were not treated with insecticide, resulting in lower productivity. The use of insecticide increased plant height, reduced tunnel length, and increased panicle length and weight. Hybrids only affected panicle weight. The hybrid that presented the highest panicle weight when using the insecticide was AG 1090. Hybrids AG 1090 and DKB 590 showed reduced grain production with increasing gallery length, whereas BRS 373 did not show a significant correlation, which may suggest a certain level of tolerance to SCB attack. This is the first study that determines the gain threshold and economic injury level and that effectively shows how much grain yield is lost by SCB attack in grain sorghum hybrids.

The control of pests and diseases is one of the main challenges of sustainable agriculture. Plantains, with an annual production of nearly 12 million tons, are a significant staple food crop in West and Central Africa, as well as in Central America. Cosmopolites sordidus is the major pests for plantains and is present in all production areas. This study assessed how the traits and associated agricultural practices of 12 crops, usually associated with plantains in Cameroun, affected the arthropods trophic network and C. sordidus abundance. The abundance and the diversity of arthropods in experimental plots associating plantains with each of the 12 tested crops were measured. Each associated crop was described by a unique profile of traits and agricultural practices. This ‘trait’ approach allowed linking the plant characteristics to the abundance of arthropods from different trophic groups. Structural equation modelling was used to analyse the interactions between associated crops traits, their associated agricultural practices and the abundance of main trophic groups. The highest abundance of C. sordidus was observed in plots with Ananas comosus and Xanthosoma sagittifolium as associated crops. These plots also had the lowest abundance of omnivores and predators. In contrast, plots with the lowest abundance of C. sordidus were those with weeds and Vigna unguiculata, where more omnivores and predators were observed. Grouping associated crops by their traits and agricultural practices allowed for drawing conclusions on a wider range than the set of plants tested. For instance, this study showed that plants from the higher strata tend to decrease ground-dwelling predators. The ideal crop traits and agricultural practices to maximize the regulation of C. sordidus should not be obtained by a single species of crop but rather by a community of associated crops.