Journal of economic entomology最新文献

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.

A field population of fall armyworm Spodoptera frugiperda (J.E. Smith) after toxicological bioassays, was subjected to laboratory selection with chlorantraniliprole and flubendiamide to investigate how resistance develops. The S. frugiperda field population from Multan (Mt Field-Pop), Pakistan, at second generation exhibited moderate resistance to chlorantraniliprole (27.48-fold) and flubendiamide (20.77-fold), very low resistance to abamectin and fenoxycarb (7.9-fold), but high resistance to lufenuron (78.3-fold) and pyriproxyfen (96.8-fold) compared to a laboratory susceptible population (LAB-SUS). Selection of S. frugiperda with chlorantraniliprole and flubendiamide over 10 generations resulted in the development of 198.7-fold and 136.5-fold resistance to these insecticides, respectively. The realized heritability (h2) of resistance to chlorantraniliprole and flubendiamide in S. frugiperda was estimated at 0.15 and 0.16, respectively. Selection for chlorantraniliprole resistance increased the resistance by 22.3-fold for flubendiamide, 17.5-fold for abamectin, and 10.9-fold for pyriproxyfen, but had no effect on resistance to lufenuron and only a slight increase in resistance (2.4-fold) to fenoxycarb. Similarly, selection with flubendiamide increased resistance to chlorantraniliprole (31.9-fold) but did not lead to resistance development against the insect growth regulators (IGRs) lufenuron, pyriproxyfen, and fenoxycarb. The inheritance analysis of chlorantraniliprole and flubendiamide resistance in S. frugiperda revealed that resistance to both diamides was autosomal, polygenic, and incompletely dominant. These findings provide important implications in managing insect resistance in S. frugiperda, including rotation of insecticides to mitigate the pest resistance.

In the 16 years since the initial detection of Drosophila suzukii Matsumura in the continental United States, integrated pest management programs in susceptible crops have been disrupted, resulting in unsustainable increases in insecticide sprays. Effective monitoring is critical for informing treatment decisions and to guide product selection when this pest is present. However, adult traps are difficult to process and poorly correlate with larval infestation in fruit. Recently focus has been placed on larval monitoring to document whether fruit are uninfested, starting to become infested, or heavily infested. We compared fruit sampling data from 4 states to determine whether these provide D. suzukii monitoring information which could better aid management decisions. We collected samples weekly for 6 wk at field edges and field interiors of berry crop plantings in Georgia, North Carolina, Michigan, and Oregon. Monitoring eggs and first instar larvae at field edges provided detection 2 wk earlier than monitoring later life stages or in field interiors. Here, we provide the first predictive models for the relationship between eggs and larvae in blackberries and blueberries. Our power analysis estimated that a minimum of 13 samples, either of individual fruit for egg counts or of 30 to 50 berry samples for larval extraction, are needed per location to detect the initial egg and larval infestation with 80% precision. These findings provide growers and other decision-makers with improved D. suzukii detection sensitivity, likely resulting in reduced pesticide application frequency and enhanced integrated pest management programs for berry crops producers.

High tunnels (HTs) are a protected agriculture tool used by specialty crop farmers. Cucumbers (Cucumis sativa L.) are well suited for HT production because of their vertical growth habit, allowing for space optimization, and repeated flowering, providing multiple harvest opportunities. However, twospotted spider mites (Tetranychus urticae Koch; TSSM), striped cucumber beetles (Acalymma vittatum Fabricius), and melon aphids (Aphis gossypii Glover) are common pests of cucumbers in HT systems, limiting production. The unique environment of HTs lacks regulation of temperatures, which can reach high levels during summer, facilitating the rapid development of pests. Here, we present results from a field study evaluating the susceptibility of cucumber cultivars to the most common insect pests in high tunnel production systems. Cucumbers were grown in HTs at three locations in Indiana, along a north-south gradient. Cultivar susceptibility was evaluated across 10 cultivars, each replicated within a single tunnel in a randomized complete block design. Our result showed that "Excelsior" and "Socrates" exhibited the lowest susceptibility to aphids. "Quirk" exhibited the lowest susceptibility to striped cucumber beetles. Cultivars including "China Long," "Itachi," and "Tasty Jade" exhibited low susceptibility to twospotted spider mites. This research highlights the impact of cultivar selection on insect pests in cucumber production, especially under high tunnel conditions.

Cytochrome P450 monooxygenases (CYP450) and trehalose play a significant detoxification role under high CO2 stress. Notably, CYP450 significantly affects trehalose metabolism of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), a devastating stored pest. To explore whether trehalose enhances CYP gene responses to CO2 stress, investigations were conducted on the 95% CO2 tolerance in 8th-instar T. castaneum larvae, whose specific CYP genes-TcCYP4BN1, TcCYP9F2, and TcCYP9AB1-were silenced, across different trehalose dietary regimes (50% flour + 50% trehalose or 100% trehalose). The 95% CO2 tolerance response was systematically evaluated through multi-dimensional analysis of gene expression levels, carbohydrate contents, and enzyme activities. Results indicated that compared with the 50% flour + 50% trehalose feeding regimen, trehalose-only diet groups exhibited downregulation of trehalose metabolism-related genes, with the notable exception of the dsCYP9F2 experimental group. As to carbohydrate contents, glucose content increased significantly on 100% trehalose diet by inhibiting the expression of TcCYP9AB1, but it decreased in the other 2 groups, a pattern that also held true for glycogen. Together, these results demonstrate that trehalose does enhance the response of CYP genes to CO2 stress, and that TcCYP9AB1 is more responsible for modulating trehalose metabolism. Future research could investigate the molecular mechanisms underlying these regulatory processes and their practical applications, potentially enhancing biocontrol techniques and advancing pest management solutions.

Drosophila suzukii (Matsumura) is an important pest affecting small fruit crops worldwide. Given its short generation time and multiple, overlapping generations annually, population monitoring remains a critical integrated pest management strategy to detect and track population dynamics throughout the season. In this 3-year study, we leverage adult D. suzukii trap captures from Scentry monitoring traps to develop a degree-day model for this invasive fly in small (<25 acre) U-pick blueberry orchards in Indiana. Three common blueberry varieties ('Bluecrop,' 'Blueray,' and 'Elliott') were also examined to identify berry characteristics known to influence D. suzukii infestation. A two-parameter generalized logistic model explained ≥ 80% of the variance between cumulative degree days and the cumulative proportion of adults captured in monitoring traps in 2021, 2022, 2023, and across all 3 years combined. Based on the combined degree-day model, monitoring traps should be deployed in early June, as the first detection of D. suzukii typically occurred in mid-June. Additionally, the model predicts that peak activity, marked by 50% of cumulative trap capture, will occur by late July. The late season 'Elliott' berries were more susceptible to infestation, while firmer berries had lower infestation rates, regardless of blueberry variety. This research improves the predictability of D. suzukii activity and infestation risk in Indiana blueberry production.

Tenebrio molitor L. (Coleoptera Tenebrionidae) is 1 of the 3 most important species of industrialized insects worldwide. Its potential as a substitute for fish meal in animal feed formulations and as a source of protein and lipid for human consumption has increased over the years. Improving the characteristics of the stock commercial colonies of T. molitor to increase biomass productivity is one of the current questions of interest for the industry. Despite their high degree of plasticity, the quantitative traits development time and pupal weight have been proven to possess sufficient levels of heritability to be impacted by selection. The objective of this study was to determine if significant differences in these 2 traits could be observed in selected populations after 3 generations of selection. Starting from a single cohort from the stock colony, mealworms were grouped in 4 selection groups (F0): completing larval development within 16, 18, 20, and 22 wk and with pupal weight ranges of 180 to 199, 200 to 219, 220 to 239, and 240 to 259 mg, respectively. Groups were selected for 3 generations to conform with the ranges established and at the end of selection, fecundity and egg viability were evaluated for F3 adults of each of the selection classes. Significant changes in development time and pupal weight were observed in the F3 in all the selected classes. The F3 also showed significant differences in fecundity, egg viability, and immature survival at the end of the F3.