Journal of economic entomology最新文献

The soybean weevil, Rhyssomatus nigerrimus (Fahraeus) (Coleoptera: Curculionidae) is an economically damaging pest on soybean in Mexico. Adult weevils are managed with insecticides. Reduced risk management could include the development of traps for monitoring. Adult weevils form mating aggregations on soybean and produce low-volume sounds. The objective was to characterize the sounds produced by groups of males and females, and to determine whether the weevil group size influences the acoustic signals. Adult weevils were field collected and then sorted into groups of males and females in the laboratory. Groups of adult males or females (3, 5, or 10) were used for acoustic recordings. Adobe Audition software was used to visualize and measure the duration and peak fundamental frequency of the sounds. Two acoustic signal patterns were produced by both males and females: paired chirps and a series of chirps. Paired chirps were produced by all group sizes of males and females. The series of chirps was produced by larger groups of males more frequently than smaller groups. For females, the series of chirps was detected more frequently in small groups of 3 females than in larger groups. Paired chirps may play a role in species identification; they have been characterized for other weevil species, and chirp durations vary among the species recorded. The series of chirps produced occur in other weevil species as well and are associated with stress or disturbance. The acoustic patterns produced by R. nigerrimus and their behavioral context could be further explored for potential inclusion in an acoustic trap to detect and monitor this weevil.

Ecological theory predicts that resilience of pollination can maintain crop pollination at an acceptable level, yet empirical evidence supporting the prediction still remains limited. This study combined field observations and simulated datasets to assess whether the resilience of pollination exists in agricultural ecosystems and to what extent it can maintain crop pollination. Fourteen squash (Cucurbita pepo L.) fields along a gradient of semi-natural habitats were selected in Kunming, Yunnan Province, China. Pollinator abundance and visitation density were sampled in 2020 and 2021. The resilience of pollination was quantified as the increase in pollen deposition by honey bees following experimental exclusion of bumble bees. Codes were developed to simulate the amount of pollen grains deposited by honey bees and bumble bees respectively. Results showed that bumble bee abundance increased significantly with semi-natural habitats, while honey bee abundance remained stable. Bumble bee exclusion resulted in a significant increase in honey bee visitation density. The proportion of semi-natural habitats significantly positively influenced the resilience of pollination. Furthermore, the resilience of pollination maintained squash pollination to 1,200 pollen grains per flower, thereby securing squash pollination. In conclusion, semi-natural habitats can enhance the resilience of squash pollination at an acceptable level in agricultural landscapes.

The spotted lanternfly (SLF), Lycorma delicatula (White) (Hemiptera: Fulgoridae), a highly polyphagous invasive pest, preferentially feeds on tree-of-heaven (TOH), Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae). However, the bacterial interactions between this pest and its host plant remain poorly understood. In this study, we investigated the bacterial community composition and functional profiles in the SLF gut, TOH leaves, and TOH rhizosphere soil using amplicon and metagenomic sequencing. This study showed that the bacterial alpha-diversity differed significantly among the 3 sample types (P < 0.05). Venn analysis identified 4 shared amplicon sequence variants (ASVs) between the TOH rhizosphere soil and SLF gut, suggesting potential bacterial interactions or transfer. Further source-tracking analysis indicated that most gut bacteria originated from the rhizosphere soil. However, the dominant taxa varied across compartments: Proteobacteria dominated both the SLF gut and TOH leaves, while Acidobacteria predominated in the TOH rhizosphere soil. Network analysis revealed significant correlations between gut and rhizosphere microbes, notably Candidatus Vidania and Fastidiosipila (P < 0.05, r = 1). Functional profiling showed that the rhizosphere microbiome was enriched in nitrogen cycling and carbon fixation pathways, whereas the gut microbiome was associated with carbohydrate metabolism and nutrient assimilation. These results provide new insights into the potential roles of microbiomes in mediating plant-insect interactions and underscore the rhizosphere as a critical microbial source for SLF. Understanding these microbial connections may support the development of innovative and sustainable pest management strategies.

Mycopesticides are crucial for integrated management of the Asian citrus psyllid (ACP, Diaphorina Citri), yet highly virulent formulations remain inadequately studied. This study aimed to optimize an oil-based formul ation of Cordyceps fumosorosea strain SCAU-CFDC01-selected for its high pathogenicity against ACP-and evaluate its synergistic potential with thiamethoxam. Key optimized parameters included corn germ oil, Tween 80 (12%), carboxymethylcellulose sodium (6%), organoclay (2%), and UV-531 (4%). Compared to unformulated conidia, the oil-based formulation of C. fumosorosea significantly increased virulence against both ACP fifth-instar nymphs and 6-d-old adult females, as indicated by increased mortality rates and decreased LT50 values. Furthermore, sublethal concentrations (LC25) of thiamethoxam synergistically enhanced mortality induced by the oil-based formulation in both life stages. Combined treatment of thiamethoxam LC25 with the oil-based formulation (1 × 106 conidia ml-1) also significantly reduced female longevity and fecundity. Lastly, molecular analysis revealed downregualtion of key genes associated with juvenile hormone signaling (Met, Kr-h1) which is a crucial reproductive regulator, and other 3 reproductive related genes (DcVg1-like, DcVgA1-like, and DcVgR) after treatments with thiamethoxam LC25 and oil-based formulation (1 × 106 conidia ml-1). These results demonstrate the synergistic potential of combining C. fumosorosea oil-based formulation with thiamethoxam for effective ACP control, offering a promising integrated pest management strategy.

The performance of commercially available corn earworm, Helicoverpa zea Boddie (Lepidoptera: Noctuidae), female sex pheromone lures that attract male moths from four different commercial vendors was evaluated to determine the duration of catch in the field. Lures were aged outdoors beneath Scentry Heliothis traps for a period of 0, 2, 4, 6, and 8 weeks before standardized field testing in New York and North Carolina. Scentry Heliothis traps baited with aged lures were monitored for male H. zea for 14 d across two independent replications in each state. Gas chromatography-mass spectrometry study (GC-MS) was used to quantify the release rates and residual pheromone content in the dispenser of 11-Z-hexadecenal (Z11-16Ald), the major pheromone compound, for a subset of field-aged lures. We found an unequal decline in H. zea attraction efficiency among commercial lure types (significant lure type × age interaction). Lure type and age were also related to trap capture (model main effects), which are two important factors when selecting lures and determining replacement intervals in the field. Release of pheromone over 24 h was significantly different among lure types. Notably, discrepancies between residual pheromone and actual emission rates in septa lure highlights the need for better commercial dispensers with longer longevity and higher pheromone controlled release. Results highlight clear differences in lure performance that could directly affect the probability of H. zea detection in the field. Impacts of these temporal emission differences may increase the frequency of lure replacement in field applications.

Chionarctia nivea Ménétriès (Lepidoptera: Arctiidae) eggs serve as an effective host for the mass-rearing various Trichogramma species. This study utilized age-stage, 2-sex life tables to assess the effects of 4 host plants, maize (Zea mays L.), Chinese cabbage (Brassica rapa L. ssp. pekinensis), pakchoi (Brassica campestris L. ssp. chinensis), and soybean (Glycine max (L.) Merr.), on the biology and life table parameters of C. nivea. The results indicated that C. nivea reared on maize and Chinese cabbage exhibited significantly shorter preadult development durations and higher preadult survival rates compared to those reared on pakchoi and soybean. Fecundity was highest on Chinese cabbage (2,388.27 eggs/female), which was significantly higher than on the other hosts. Similarly, the net reproduction rate (R0) was highest on Chinese cabbage (716.48 eggs/female), surpassing those recorded on maize, pakchoi, and soybean. The intrinsic rate of increase (r) was significantly higher for populations reared on maize (0.10 d-1) and Chinese cabbage (0.10 d-1) compared to those on pakchoi (0.07 d-1) and soybean (0.05 d-1), with no significant difference observed between maize and Chinese cabbage. Conversely, the finite rate of increase (λ) showed no significant variation the 4 host plants. Collectively, these results suggest that Chinese cabbage is the most suitable host for the mass-rearing C. nivea, facilitating enhanced production of Trichogramma spp. production for biological control programs.

Historically, spider management has received relatively little attention in the literature compared to insect pests, and few studies have examined the efficacy of chemical management strategies on orb weaver mortality and web site fidelity. However, the introduction and rapid spread of the Jorō spider, Trichonephila clavata (L. Koch, 1878; Araneae: Araneidae), in North America has created a wave of media and public awareness. Characterized by its large size, bright coloration, dense aggregations, and durable webs, this species has garnered concern from residents who wish to manage this pest. Internet-based advice ranges from using products labeled for arthropod control to common products around the home. Our study evaluated spider mortality from eleven separate products and two control treatments (water and no treatment at all). High doses of pyrethroid pesticides or essential oil and detergent-based pesticides were highly effective in killing T. clavata. Although spraying foaming dish soap and machine lubricant also led to high mortality rates, we do not condone the use of products outside of their registered label use. We also evaluated several products that did not cause high mortality for their potential to cause T. clavata to abandon their webs-a result that may be just as desirable for residents-though none of these products led to high rates of web abandonment. We strongly recommend that property managers carefully weigh the pros and cons and safety aspects of different management strategies (including mechanical management) and assess whether T. clavata management is warranted in the first place.

Flavescence dorée (FD) is a quarantine grapevine disease associated with FD phytoplasmas (FDp). No curative methods are available for treating FDp-infected grapevines and the mandatory control measures consist of insecticide applications against the main FDp insect vector Scaphoideus titanus (Ball 1932) (Hemiptera: Cicadellidae) and the removal of infected grapevines. Despite such systematic control measures, FD has become widespread across numerous European winegrowing areas. Meanwhile, several alternative vectors capable of acquiring and transmitting FDp have been identified and additional host plant species have been found harboring FDp genotypes associated with FD outbreaks. This highlights the importance of extending disease management efforts beyond individual vineyard plots and considering the broader landscape as an element of FD epidemiology. This study examined the potential epidemiological role of the alternative FDp vector Orientus ishidae (Matsumura 1902) (Hemiptera: Cicadellidae) and its association with the host plant Corylus avellana. A hatching experiment was conducted to confirm the role of C. avellana as a host plant for O. ishidae in the Swiss southern Alps. Meanwhile, a habitat management (HM) experiment was designed, involving the removal of C. avellana resprouts acting as O. ishidae host plant and shelter in the surroundings of vineyards. The removal of the C. avellana resprouts confirmed to be a good strategy to reduce the O. ishidae population in the vineyard and the related risk of exchange of phytoplasma between the wild compartment and adjacent cultivated vineyards. The study concludes by discussing the potential for integrating this HM strategy into conventional FD control methods.

Drosophila suzukii Matsumura is a nearly worldwide invasive pest that causes damage to ripening fruit, particularly raspberries. Biological control in an integrated pest management strategy may be an alternative to repeated insecticide applications. We evaluated the effects of using multiple commercially available agents against D. suzukii in raspberries. In the laboratory, the combination of the pupal parasitoid Muscidifurax raptorellus Kogan and Legner (Hymenoptera: Pteromalidae) and predators Orius insidiosus Say (Heteroptera: Anthocoridae) and Chrysoperla carnea Stephens (Neuroptera: Chrysopidae) reduced D. suzukii to the lowest level compared to any 1 species or 2 species combinations in a substitutive design. However, in caged plants with ripening fruit in a greenhouse, M. raptorellus and O. insidiosus together were more effective against D. suzukii than the 3 species combination. In high tunnels, M. raptorellus and O. insidiosus were ineffective against D. suzukii, and spinosad applications with or without M. raptorellus and O. insidiosus resulted in equally low numbers of D. suzukii. In the field, M. raptorellus and O. insidiosus and Pachycrepoideus vindemmiae Rondani (Hymenoptera: Pteromalidae) releases in raspberry plots with sweet alyssum were less effective against D. suzukii than spinosad applications to plots with or without sweet alyssum as a banker plant. Hymenoptera, particularly Figitidae: Eucoilinae as determined by barcoding, were more abundant in raspberries adjacent to sweet alyssum than in raspberry plots without sweet alyssum. With the discovery and redistribution of figitid parasitoids of larval D. suzukii, future research on their effects in combination with banker plants like sweet alyssum and releases of predators is needed.

The eastern bat bug, Cimex adjunctus Barber (Hemiptera: Cimicidae), is an ectoparasite of bats that can occasionally infest human dwellings, posing a potential public health concern. When found in homes, they are often treated with insecticides labeled for bed bugs (Cimex lectularius L.). However, there are no data available on the efficacy of these pesticides against bat bugs. This study assessed the efficacy of 3 commercial insecticide sprays containing pyrethroid or pyrethroid-neonicotinoid mixture and 2 insecticide dusts containing deltamethrin or diatomaceous earth (DE) against a field-collected strain of bat bugs. One susceptible and 2 resistant bed bug strains were included for comparison. Exposure to dry pyrethroid or a pyrethroid-neonicotinoid mixture residue for 5 min caused 90% to 100% mortality in bat bugs and the susceptible bed bug strain, whereas only 0% to 13% mortality in the 2 resistant bed bug strains. Brief (crossing a 2.5 cm treated band) or continuous exposure to 4.75% deltamethrin dust caused 100% mortality to bat bugs and the susceptible strain of bed bugs, but less than 20% mortality in the 2 resistant strains of bed bugs. DE dust caused 100% mortality to bat bugs and all bed bug strains, but the time to achieve this was much longer than with deltamethrin dust treatment (4 to 6 d compared to 4 h). Bat bugs showed similar susceptibility to the tested insecticides as the susceptible bed bug strain, except that a slower mortality occurred in the CrossFire (0.4% clothianidin, 0.01% metofluthrin, 1% piperonyl butoxide) spray treatment.