Journal of economic entomology最新文献

Transgenic corn (Zea mays L.) expressing insecticidal toxins from Bacillus thuringiensis (Bt) helps to control or suppress injury from a range of target insect pests. This study summarizes the yield benefits of Bt corn from field trials in Georgia, North Carolina, and South Carolina evaluating Bt and non-Bt corn hybrids from 2009 to 2023. For Cry1A.105 + Cry2Ab2 and Cry1Ab + Cry1F Bt corn, the percentage increase in yield between Bt and non-Bt corn hybrids did not vary significantly among years or states. Across years, the percentage increase in yield for both Bt traits relative to non-Bt corn hybrids increased with planting date, indicating that the yield benefit of planting Bt corn was greater later in the growing season. On average, Bt hybrids in both families had a significantly higher yield compared to their non-Bt pairs, with yields declining in later planting dates. Yields declined with increasing kernel injury from Helicoverpa zea (Boddie) and leaf injury from Spodoptera frugiperda (J. E. Smith) in both Bt and non-Bt hybrids. While insect pressure increased in later planted corn trials, identifying causal relationships between increases in insect damage and associated yield losses in corn is challenging given the numerous factors that influence corn yield during the season. In addition to illustrating the highly variable yield benefits of planting Bt corn, our study suggests that yield increases in Bt corn may occur more frequently than previously documented in the southeastern United States.

Xylosandrus crassiusculus Motschulsky and Xylosandrus germanus Blandford are serious ambrosia beetle pests in ornamental nurseries. Three ethanol baits, AgBio low release (LR), AgBio high release (HR), and Trécé are commercially available for use in bottle traps to determine flight activity of adult Xylosandrus spp. However, release patterns of ethanol from these baits under varying temperatures and captures of Xylosandrus spp. are poorly understood. Thus, the objectives of this study were (i) to determine ethanol release rates from these baits under constant and variable temperatures and (ii) to compare relative adult Xylosandrus spp. captures using these baits in ornamental nurseries. When 3-d difference (3-d difference) bait weights were recorded under constant 15.6, 21.1, 26.7, and 32.2 °C, an increase in release rates was recorded with an increase in temperature from 15.6 to 32.2 °C for LR bait. At 32.2 °C, no increase or reduction in the 3-d-difference weights was found for the HR and Trécé baits, respectively, compared to LR bait. The 3-d-difference weights were steady with all 3 baits when temperatures gradually increased and decreased in variable sequence for 30 d. In 2022, 2023, and 2024, although all 3 baits captured adult X. crassiusculus and X. germanus, LR bait captured significantly more numbers of X. crassiusculus than the other 2 baits in 2022 and 2023, and in 2024, X. crassiusculus captures were greater in traps with the Trécé bait than the other 2 baits. Thus, ethanol baits can effectively detect the early flight activity of Xylosandrus spp. adults in ornamental nurseries.

This work aimed to optimize olive fruit fly (OFF) Bactrocera oleae (Rossi) (Diptera: Tephritidae) monitoring and integrated management, thereby ensuring optimal and less-costly decision-making and timely intervention. Field trials in Andalusia (Spain) were undertaken over 2 years to optimize trap model, color, size, and density for the accurate determination of pest spatial distribution and damage as a function of olive cultivar. McPhail traps and yellow sticky panels outperformed the other 4 models with respect to the number of OFF captured. However, McPhail traps caught more natural enemies than yellow sticky panels and so sticky panels were selected to unravel the effect of color on the number of both OFF and natural enemies [hymenopteran parasitoids (Psyttalia concolor) and lacewings (Chrysopidae)] captured. Yellow sticky panels outperformed white, green, and blue ones for the number of OFF captured and captured the fewest natural enemies. When comparing the surface area of yellow sticky panels, 20 × 25 and 10 × 25 cm double-sided panels were equally effective at catching OFF. However, large double-sided yellow sticky panels caught significantly more natural enemies than the small double-sided panels, a key result for developing a less costly and environmentally friendly monitoring system. Furthermore, it was shown that the damage curve had a cultivar-based shape, i.e., for the same population size of OFF the damage caused varied depending on cultivar. Finally, 15 sticky panels per hectare were the optimal number for estimation of OFF spatial distribution. The present research provides key information for new trap design, OFF forecasting, and IPM development.

House flies, Musca domestica L. (Diptera: Muscidae), are commonplace pests in both urban and agricultural settings. The potential for house flies as vectors of many disease-causing organisms to humans and animals, coupled with their incessant nuisance behaviors toward these hosts has resulted in a desire to manage their populations. Although many house fly management tools are available, insecticide use continues to predominate as the preferred choice. One such option, insecticidal baits, is commercially available in a variety of active ingredients that encompass several modes of action. Though they can be effective, resistance to many of the active ingredients used in bait formulations has been documented. The primary pathway for resistance evolution to bait products likely has been selection at the targeted adult stage. However, exposure at the larval stage may occur when these products are scattered on substrates, contaminating sub-surface developmental areas and ultimately, playing a selective role as well. A study was conducted to assess the potential mortality effects of insecticidal bait products on house fly larval development when applied according to the manufacturer's recommended label rate. Adult house fly emergence was reduced by nearly 40% due to treatment, supporting the implication that bait-driven mortality during larval development may represent a previously unrecognized selection pathway contributing to resistance evolution against these products.

Chemical control is currently the main strategy for managing brown marmorated stink bug, Halyomorpha halys (Stål). However, chemical pesticides can harm nontarget species, including natural enemies of H. halys. Pesticides with high toxicity to H. halys and low toxicity to its parasitoids need to be identified to support H. halys management. This is not only for natural biological control but also for preemptive classical biological control of H. halys by parasitoids. Here, we assessed the contact toxicity of residues of eight insecticides against H. halys and three of its main parasitoid species (Anastatus japonicus Ashmead (Hymenoptera: Eupelmidae), Trissolcus japonicus Ashmead (Hymenoptera: Scelionidae), Trissolcus cultratus Mayr (Hymenoptera: Scelionidae)). This study aims to provide valuable insights for preemptive classical biological control of H. halys using these parasitoids. Our results showed that A. japonicus exhibited higher tolerance to the tested pesticides, while T. japonicus was the most sensitive species. Among the pesticides, chlorantraniliprole had the lowest overall impact on all three parasitoid species. Additionally, acetamiprid, azadirachtin, and rotenone were found to be harmless to A. japonicus. Acetamiprid, however, was slightly harmful to T. cultratus. The remaining pesticides showed moderate to significant harmful effects on the parasitoids. For H. halys adults and fifth instars, the pesticides tested caused no mortality within the 24 h exposure. However, young nymphs were susceptible to the tested pesticides. Fenpropathrin had the highest toxicity to H. halys, killing 83.3%, 52.8%, and 19.4% of second, third, and fourth instars in a 24 h exposure. Fenpropathrin, acetamiprid, cyfluthrin, azadirachtin, and dinotefuran were all slightly harmful to the first instar nymphs. The other pesticides were harmless to H. halys in a 24 h exposure. Halyomorpha halys mortality increased with the contact time with the residue. Mortality of fourth and fifth instars of H. halys was >70% for fenpropathrin, cyfluthrin, dinotefuran, abamectin-aminomethyl, and acetamiprid if exposure continued for 7 d. Acetamiprid was effective in controlling H. halys nymphs but exhibited varying levels of toxicity towards the three tested parasitoid species, depending on the residue age and exposure time. Azadirachtin showed lower overall toxicity to beneficial insects, suggesting that these materials could be used to manage H. halys while minimizing harm to key beneficial species.

Grapholita molesta (Busck) (Lepidoptera: Tortricidae) is a major pest of many fruit trees. The large-scale artificial propagation technology of the insect is the basis for the field application of the sterile insect technique and biological control products based on host mass reproduction. However, a low-cost diet with easily accessible materials remains lacking. In this study, we assessed the insect rearing performance feeding on 3 artificial diets: D1: an artificial diet based on wheat bran and soybean powders; D2: an artificial diet based on soybean powder, maize powders, and tomato sauce; and D3: an artificial diet based on soybean powder, maize powder, tomato sauce, and wheat bran, with apples as a control, using 2-sex life table. At 26 ± 1 °C, 70 ± 5% humidity, and 16:8 h L:D photoperiod, the biological indicators of G. molesta fed D1 were consistent with those fed apples, with a larval stage of 14.88 d, a pupal stage of 7.57 d, adult longevity of 22.69 d, egg deposition count of 223.22, intrinsic rate of increase (r) of 0.1359, finite rate of increase (λ) of 1.1456, and net reproductive rate (R0) of 94.50. D1 was used to continuously rear G. molesta population for 5 generations, all life parameters remained normal. These results indicated that the artificial diet based on wheat bran and soybean powder could be used for rearing of the insect. This study proposes an available and cost-effective artificial diet for G. molesta, facilitating the application of green prevention and control technology.

Debate over resistance management tactics for genetically engineered (GE) crops expressing insecticidal toxins is not new. For several decades, researchers, regulators, and agricultural industry scientists have developed strategies to limit the evolution of resistance in populations of lepidopteran and coleopteran pests. A key attribute of many of these events was insecticide resistance management (IRM) strategies designed around a presumed high-dose expression sufficient to kill 99.5% of exposed larvae for some of the main target pests in corn, Zea mays L. and cotton, Gossypium hirsutum L. In contrast, other target pests did not meet this high-dose criterion. Similarly, the recent release of ThryvOn cotton that expresses thysanopteran and hemipteran active Mpp51Aa2.834_16 toxin is not high dose, working on a combination of behavioral and sublethal effects to suppress populations. This unique mode of control has generated considerable uncertainty about what IRM strategies will be most effective to limit field-evolved resistance to this unique spectrum of pests. The goal of this manuscript is to present several knowledge gaps that exist in proposed Mpp51Aa2 IRM plans, focusing on its activity on thrips, Frankliniella spp. Addressing these gaps will be crucial to limit resistance and preserve the benefits that this technology may provide by alleviating reliance on conventional insecticides and seed treatments. Broadly, these considerations will be important for future GE events that are non-high dose but remain valuable components of a more holistic insect management programs that integrate multiple tactics to reduce conventional insecticide use for challenging pests.

Megalurothrips usitatus (Bagnall) (Thysanoptera: Thripidae) is an important pest of cowpeas, Vigna unguiculata (L.) Walp., and can cause severe damage to the crop. Lasioseius lindquisti (Tseng) (Acari: Blattisociidae) and Lasioseius scapulatus (Kennett) (Acari: Blattisociidae) are 2 mites used against M. usitatus in Hainnan, China. The functional responses of these mites were examined in the laboratory. Lasioseius lindquisti showed a type III functional response, with a maximum prey consumption of 22.38 ± 0.63 per day. Its optimal search density for each unit in this experiment was 10.27 ± 0.50 per day. Lasioseius scapulatus showed a type II functional and an attack rate on 1st instars of M. usitatus of 0.83 ± 0.23. The handling time (h) of L. scapulatus was 0.074 ± 0.018 (means ± SE), while the maximum attack rate (T/Th) of adult females on 1st instar thrips was 13.51. Our results showed that both L. lindquisti and L. scapulatus are potentially useful predators of M. usitatus.

The carpophilus beetle, Carpophilus truncatus Murray, 1864 (Coleoptera: Nitidulidae) is an invasive pest recently detected in California's tree nut crop orchards. Here we report a simple, labor-saving, and cost-effective rearing system for C. truncatus utilizing banana and industrial sand components. Banana slices served as both a larval and adult diet source as well as a moisture source to facilitate pupation within the underlying sand. The combination of banana and sand within a single container successfully supported the development of all C. truncatus life stages over multiple generations. The average developmental times recorded in rearing units placed under environmental conditions of 26°C, 60% relative humidity, and 16:8 h (light:dark) photoperiod were: egg to wandering stage larva, 7.54 days; wandering stage to adult, 11.08 days; and adult longevity, 94.33 days. These banana-sand rearing units facilitated the easy collection of all C. truncatus developmental stages, except for eggs. To address this challenge, standalone oviposition chambers utilizing a lima bean-based agar diet were evaluated. These chambers effectively enabled the collection as well as tracking of eggs for different research purposes. The average developmental time recorded for eggs, from initial oviposition to neonate hatching, was 3.20 days. These rearing as well as egg collection approaches provide cost-effective tool to investigate biology, life-history traits and ecology, as well as evaluate approaches to control this invasive pest.

The lesser mealworm Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae), an important insect pest of stored-product commodities and poultry production systems, is regarded among the most difficult species to control. It has developed resistance to many chemical insecticides, and though various cultural and biological methods have been assessed and identified as possible factors for its control, none are currently implemented. Entomopathogenic nematodes are often successfully employed as alternative to chemicals biocontrol agents of various insect species, including pests of stored products; nevertheless, their evaluation as potential biocontrol factors of the lesser mealworm is not efficiently scrutinized. In the current study, single A. diaperinus larvae were exposed to six doses of Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), Steinernema carpocapsae (Weiser) (Rhabditida: Steinernematidae), and Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae), for 4 and 8 d, and mortality was recorded at 3 different temperature regimes, i.e., 25 oC, 30 oC, and 35 oC. The study concludes that S. carpocapsae and S. feltiae are both highly virulent against A. diaperinus larvae and may be considered as promising biological control agents for reducing lesser mealworm infestations when applied at a rate of 70 IJs/cm2 at 25 oC. When assessed at 30 oC, both species were effective at the same rate though causing lower mortality of ~60% and ~50%, respectively, whereas their efficacy was low at 35 oC.