Monitoring pest populations is essential to integrated pest management. However, adopting tools like pheromone traps is often stymied by a lack of clear information. For instance, one may use different trap types and change lures at various frequencies. Furthermore, the correlation of trap capture with crop damage may be unclear. Additionally, a perceived lack of need, high cost, and time commitment may reduce trap use. Therefore, this study focuses on Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), western bean cutworm monitoring in dry bean to determine the (1) effectiveness of four trap types on the number and timing of moth capture, (2) the relationship amongst moth catch, crop damage, and insecticide timing, (3) the ideal pheromone change frequency, and (4) trapping cost and labor. Trap types were compared on three (2020) and four (2021) fields in Scotts Bluff County, Nebraska, USA. Insecticide application timing was compared on three of these fields in both years, and S. albicosta damage was assessed. The bucket trap caught the most moths in three of four fields in 2021. Unfortunately, there was a low correlation between S. albicosta counts and feeding damage. Insecticide application after peak moth flight was more effective at reducing feeding damage than an application before canopy closure, where sufficient pest pressure occurred. In summary, pheromone trapping is a poor predictor of S. albicosta damage in dry bean; however, it can facilitate accurate insecticide timing. Further, manual trapping techniques remain the most effective and cost-efficient, with further efficiencies realized with pheromone replacements at 4-week intervals.

The western bean cutworm ( Striacosta albicosta) is a primary pest of corn and dry edible bean, for which control measures are often warranted. Inundative releases of Trichogramma ostriniae have been used to control lepidopterous pests, such as the European corn borer ( Ostrinia nubilalis), in eastern North America (e.g., New York, Virginia). However, no prior field studies have assessed T. ostriniae as a biological control agent in the North American Great Plains. Objectives for this study were (i) to determine the suitability of S. albicosta as a host for T. ostriniae and (ii) to assess the feasibility of T. ostriniae as a biological control agent of S. albicosta in Nebraska corn and dry edible bean fields. Dispersal and parasitism were monitored with yellow sticky cards and sentinel egg masses (O. nubilalis, S. albicosta, and Ephestia kuehniella) at 36 locations surrounding a central release point. Trichogramma ostriniae adults tended to be concentrated near the point of release. However, egg parasitism was so low that the minimum rates of T. ostriniae needed for effective control could not be determined. Our evidence indicates that the low parasitism measured in this study may indicate low suitability of T. ostriniae to Western Nebraska and, possibly, the Great Plains.

Western bean cutworm, Striacosta albicosta (Smith; Lepidoptera: Noctuidae), is a major pest of corn and dry beans in its historic and expanded ranges in the North American western Great Plains and Great Lakes Region, respectively. In corn, S. albicosta ear feeding damage can significantly reduce yield and introduce avenues for secondary fungal infections. Management practices currently rely on transgenic crops expressing effective Bacillus thuringiensis (Bt) protein, of which only the VIP3A protein is effective against S. albicosta, and/or labor-intensive scouting and chemical control. However, limited research on biological control options for this critical pest has been conducted. This study identifies key trophic interactions between S. albicosta and predatory arthropods in corn fields. Field surveys identified a community of 21 predator taxa present in Nebraska corn fields where S. albicosta eggs and larvae were present. The most common taxa were as follows: Hippodamia convergens (Gu & eacute;rin-M & eacute;neville; Coleoptera: Coccinellidae), Coleomegilla maculata (De Geer; Coleoptera: Coccinellidae), Orius insidiosus (Say; Hemiptera: Anthocoridae), and green lacewings (Neuroptera: Chrysopidae). Additionally, molecular gut-content analysis via PCR confirmed the predation of S. albicosta by several well-known biological control agents, including H. convergens, O. insidiosus, C. maculata, and Chrysopidae larvae and adults. Coleomegilla maculata consumed more S. albicosta eggs and larvae than H. convergens in feeding trials, although egg consumption by C. maculata was unaffected by the presence of corn pollen, an important supplemental food for this species. Exploring the trophic interactions between S. albicosta and its predators will provide information necessary to improve conservation biological control for S. albicosta integrated pest management.

Widespread use of genetically engineered maize targeting the corn rootworm complex ( Diabrotica species) has raised concerns about insect resistance. Twelve years of university field trial and farm survey data from 10 US Corn Belt states indicate that maize hybrids expressing toxins derived from the bacterium Bacillus thuringiensis (Bt maize) exhibited declining protection from rootworm feeding with increased planting while pest pressures simultaneously decreased. The analysis revealed a tendency to overplant Bt maize, leading to substantial economic losses; this was particularly striking in eastern Corn Belt states. Our findings highlight the need to go beyond the “tragedy of the commons” perspective to protect sustainable use of Bt and other crop biotechnology resources. We propose moving toward a more diversified and transparent seed supply.

ContextInterest is growing among farmers in the Midwestern US region in the potential benefits of establishing cereal rye (Secale cereale L.) as a cover crop. However, they are concerned about the implications and potential trade-offs due to this practice.ObjectiveWe aimed to evaluate the effects of cereal rye cover crop termination at or before soybean planting on soybean (Glycine max [L.] Merr.) seed yield.MethodsField experiments were conducted from 2019 to 2021 across 28 location-years in the Midwestern US. Treatments consisted of no cereal rye, cereal rye termination before soybean planting, and termination at planting. Cereal rye was chemically terminated at each termination timing. Cereal rye biomass and soybean yield were assessed.ResultsDelaying cereal rye termination in soybean systems increased rye biomass, but its impact on soybean yield was inconsistent. Results showed that delayed termination did not reduce soybean seed yield in 25 of 28 location-years compared to a no cover crop treatment. There was no clear evidence indicating that a threshold level of cereal rye biomass accumulation reduced soybean seed yield.ConclusionsOur results suggest that farmers who adopt cereal rye as a winter cover crop in the examined region have a flexible management window for terminating cereal rye, as the timing of termination had minimal effect on soybean seed yield. However, there were no significant soybean seed yield benefits that would justify the associated cost with the use of cover crops. Therefore, conducting long-term studies in the future is highly recommended to better understand how cereal rye cover crops can influence soybean seed yield and soil quality properties over time. Further studies should also investigate the aspect of non-chemical rye management to assess its potential cost-saving effects for farmers adopting this system.ImplicationsThese findings hold several implications for farmers, agronomists, and stakeholders. The increased cereal rye biomass due to delayed termination could offer greater soil benefits. While the inconsistent effects on soybean yield imply flexible termination options for cover crop adoption, the absence of substantial yield benefits underscores the importance of considering both short-term costs and long-term sustainability goals.

The impact of selected foliar insecticides against pest insect populations in soybean was evaluated at the UNL South Central Agricultural Laboratory (Clay County, NE) in 2023.The experimental design was an RCB with 4 replicates.Plot size was 12 rows × 27.5 ft length @ 30-inch row spacing.'NK 28-T3XF' soybean seed was planted on 8 May.Plant populations were evaluated on 9 Jun.The total number of plants in the center 2 rows of each plot was recorded and converted to plants per acre (PPA) (Table 1).Adult Japanese beetle emergence was first observed in the study area on 23 Jun.Foliar insecticides were broadcast over the plant canopy in a 15

Cost-effective and reliable sampling procedures are crucial for integrated pest management. Sweep net sampling is commonly used for stink bugs (Hemiptera: Pentatomidae) in soybean, with sample size being the number of sets of sweeps, and sample unit size the number of sweeps in each set. Sample unit size has received little attention, but can affect sampling parameters. Here, two sample unit sizes (10 vs. 25 sweeps) were compared for the sampling of stink bug taxa. On average, sampling for stink bugs took 3.6 more minutes with the 25-sweep than with the 10-sweep sample unit size. Generally, estimates of the mean number of stink bugs per sweep were similar between the two sample unit sizes for Euschistus spp. and Chinavia hilaris combined ("combined herbivores") and Euschistus spp. The 25-sweep sample unit size had a higher probability of detecting combined herbivores, Euschistus spp. and Podisus spp., lower standard errors and relative variance for combined herbivores and Euschistus spp., lower standard errors for C. hilaris, and higher relative net precision [which accounts for sampling cost (i.e., time)] for combined herbivores and Euschistus spp. Taken together, the better probability of detection, precision and efficiency of the 25-sweep sample unit size support the continued use of sampling plans developed for that sample unit size. The optimization of sample unit sizes is an important factor that should be accounted for in the development of sampling plans.

Stink bugs represent an increasing risk to soybean production in the Midwest region of the United States. The current sampling protocol for stink bugs in this region is tailored for population density estimation and thus is more relevant to research purposes. A practical decision-making framework with more efficient sampling effort for management of herbivorous stink bugs is needed. Therefore, a binomial sequential sampling plan was developed for herbivorous stink bugs in the Midwest region. A total of 146 soybean fields were sampled across 11 states using sweep nets in 2016, 2017, and 2018. The binomial sequential sampling plans were developed using combinations of five tally thresholds at two proportion infested action thresholds to identify those that provided the best sampling outcomes. Final assessment of the operating characteristic curves for each plan indicated that a tally threshold of 3 stink bugs per 25 sweeps, and proportion infested action thresholds of 0.75 and 0.95 corresponding to the action thresholds of 5 and 10 stink bugs per 25 sweeps, provided the optimal balance between highest probability of correct decisions (≥ 99%) and lowest probability of incorrect decisions (≤ 1%). In addition, the average sample size for both plans (18 and 12 sets of 25 sweeps, respectively) was lower than that for the other proposed plans. The binomial sequential sampling plan can reduce the number of sample units required to achieve a management decision, which is important because it can potentially reduce risk/cost of management for stink bugs in soybean in this region.

Stink bugs (Hemiptera: Pentatomidae) are agricultural pests of increasing significance in the North Central Region of the United States, posing a threat to major crops such as soybean. Biological control can reduce the need for insecticides to manage these pests, but the parasitism of stink bugs by Tachinidae (Diptera) is poorly characterized in this region. The objective of this study was to evaluate the rate of parasitism of stink bugs by tachinids over 2 yr from nine states across the North Central Region. Parasitism was assessed by quantifying tachinid eggs on the integument of stink bug adults. Parasitism rates (i.e., percent of adult stink bugs with tachinid eggs) were compared across stink bug species, states, stink bug sex, and years. The mean percent parasitism of stink bugs by tachinids was about 6% across the region and did not differ among stink bug species. Mean percent parasitism was significantly higher in Missouri than in northern and western states. In addition, male stink bugs had significantly higher mean percent parasitism than females. Stink bug species commonly found in soybean in the region showed some parasitism and are therefore potentially vulnerable to oviposition by these parasitoids. This is the first study to characterize the level of parasitism of stink bugs by tachinids across the North Central Region.

Stink bugs (Hemiptera: Pentatomidae) are an increasing threat to soybean (Fabales: Fabaceae) production in the North Central Region of the United States, which accounts for 80% of the country's total soybean production. Characterization of the stink bug community is essential for development of management programs for these pests. However, the composition of the stink bug community in the region is not well defined. This study aimed to address this gap with a 2-yr, 9-state survey. Specifically, we characterized the relative abundance, richness, and diversity of taxa in this community, and assessed phenological differences in abundance of herbivorous and predatory stink bugs. Overall, the stink bug community was dominated by Euschistus spp. (Hemiptera: Pentatomidae) and Chinavia hilaris (Say) (Hemiptera: Pentatomidae). Euschistus variolarius (Palisot de Beauvois) (Hemiptera: Pentatomidae), C. hilaris and Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) were more abundant in the northwestern, southeastern and eastern parts, respectively, of the North Central Region of the United States. Economically significant infestations of herbivorous species occurred in fields in southern parts of the region. Species richness differed across states, while diversity was the same across the region. Herbivorous and predatory species were more abundant during later soybean growth stages. Our results represent the first regional characterization of the stink bug community in soybean fields and will be fundamental for the development of state- and region-specific management programs for these pests in the North Central Region of the United States.