Grain aeration is a pest management tactic whose efficacy is more strongly affected by climate and environmental conditions than insecticides. We evaluated whether the already widespread use of grain aeration is feasible in the Middle East in silico given the arid and hot weather conditions prevalent in the region. Historical weather data from 2004 to 2023 was obtained for 77 sites in 13 countries in the Middle East, and Sitophilus oryzae populations were predicted for a subset of 10 locations spanning the range of climates in the region. We investigated the potential efficacy of aeration triggered at 15, 18, or 21  °C (compared to unaerated) in silico starting in one of five months from July to November. There was little accumulation of hours below 15  °C, a key developmental threshold, in most of the countries prior to November. Modelled S. oryzae populations were highest in hot desert and warm Mediterranean climates. Aeration was predicted to not suppress populations in the hot desert climate, especially in Egypt, but aeration is predicted to suppress population increase in the relatively milder Mediterranean climates. The strength and direction of the correlation (eg strongly positive) between predicted S. oryzae abundance and grain temperature or hours below threshold indicates effective aeration. Thus, when grain is aerated in locations with climate close to the upper developmental threshold of S. oryzae, it will not be effective. Our study illustrates grain aeration is predicted to be effective in some locations of the Middle East, with climatic features of the biome determining efficacy.

Corn rootworms are the leading insect pests of corn in the growing regions of North and Central America, with an estimated direct loss in revenue exceeding $2 billion USD. Damage is primarily caused by western corn rootworm (Diabrotica virgifera virgifera LeConte); however, Mexican corn rootworm (Diabrotica virgifera zeae Krysan & Smith) also causes significant losses. Little life history is known about D. v. zeae, so information on D. v. virgifera is often referenced, which may lead to incorrect assumptions. We used niche space models to assess the potential differences in the niche space and potential distribution of both subspecies under current and future climatic scenarios (SSP126 and SSP585). Interestingly, the niche spaces of the subspecies did not overlap, and there was a mismatch of the bioclimatic variables that contributed most to the models. The current potentially highly suitable area of D. v. zeae was much smaller, and both subspecies' highly suitable areas expand in the models (2.26- and 1.35-fold for D. v. virgifera and D. v. zeae by 2080 SSP585) and shift to the north and west, with greater deviations noted in later time periods and with greater environmental change. However, the overlap of highly suitable areas is consistently small, ranging from 4.2% to 6.3%. More research effort is needed on the basic ecology, behavior, and toxicology of D. v. zeae, as it may further differ from D. v. virgifera. Additionally, more universal surveys of both subspecies are needed in the likely case of expansion.

Infestation by stored-product insects leads to significant postharvest losses in the USA and globally, which requires efficient and effective management. Overreliance on a single pesticide, or mode of action, may result in the evolution of resistance. Deltamethrin is extensively used to manage stored-product insects in the USA and globally, because of its efficacy, quick knockdown, ready breakdown in the environment, and low mammalian toxicity. Tribolium castaneum, T. confusum (Coleoptera: Tenebrionidae), and Sitophilus zeamais (Coleoptera: Curculionidae) have all shown varying levels of susceptibility and potential resistance to pyrethroids across different regions. The study evaluated the toxicological responses of selected field-derived and laboratory populations of three major stored product insect species to deltamethrin under laboratory conditions. Adult mixed sex beetles were exposed to a range of deltamethrin concentrations (0.0157-1.57 & times; 105 ng/cm2) with the highest concentration being 1.57 & times; 105 ng/cm2for five exposure durations (0.5, 1, 24, 48, and 72 h) in impregnated filter paper bioassays to assess the proportions of adults that were either alive, affected (knocked down), or dead. Results demonstrated clear concentration and time-dependent responses in all species. Susceptible strains of all species exhibited up to 100% mortality with >= 1.00 & times; 104 ng/cm2 deltamethrin within 48-72 h, while resistant S. zeamais and T. confusum strains had over 30% live or affected individuals even at the highest concentration after 72 h. These findings highlight species and strain specific variation in deltamethrin susceptibility and underscore the importance of continued resistance monitoring in stored-product insect management programs.

There is an increasing demand for organically certified practices throughout the postharvest supply chain. Yet, evaluating mortality and sublethal effects from organic chemical control options have received less attention. Thus, the aims of this study were to evaluate the direct mortality and changes in mobility of Prostephanus truncatus and Sitophilus zeamais when using (i) fresh residues or (ii) 7-mo-aged residues on maize from a suite of organically approved grain protectants (3 formulations of 5% pyrethrins, or 8.66% spinosad) compared to a conventional insecticide (4.75% deltamethrin) and water-treated negative control in a grain bin environment. Adults were exposed to residues continuously for 24 or 168 h. There were 92% to 99% and 78% to 88% fewer dead S. zeamais and P. truncatus, respectively, after exposure to maize with pyrethrins or H2O compared to deltamethrin, whereas there were 16% fewer to 1.4% more dead S. zeamais and P. truncatus after exposure to maize treated with spinosad. Exposure to maize treated with pyrethrins, spinosad, or deltamethrin reduced progeny production by 43% to 99% for S. zeamais and by 27% to 100% for P. truncatus compared to H2O-treated grain. There were 2.4-fold and 4.1-fold more progeny produced by S. zeamais and P. truncatus, respectively, on maize aged 7 mo compared to initially treated with a grain protectant. We found consistent sublethal reductions in movement by S. zeamais after exposure to maize treated with both organic and conventional insecticides. Overall, our work helps raise the profile of the importance in assessing available organic options for management of insects after harvest.

ABSTRACT Effective monitoring of stored‐product insect pests is essential for timely intervention and informed decision‐making in integrated pest management (IPM) programs. In practice, however, routine inspection of sticky traps remains labor‐intensive and is often constrained by limited temporal resolution and observer variability. Here, we evaluate an automated, image‐based monitoring system designed to estimate moth populations from sticky traps under realistic storage conditions. The system combines camera‐equipped traps with image preprocessing and a convolutional neural network (CNN) to distinguish moths from non‐moth insects and other trap‐associated artifacts. A dataset of 1739 high‐resolution sticky‐trap images collected under variable lighting, trap orientation, and contamination levels was annotated and used for model training and evaluation. The automated approach achieved an overall classification accuracy of 95.8%, with precision, recall, and F1‐scores consistently exceeding 90%, demonstrating reliable performance even in images containing overlapping insects and debris. Beyond classification accuracy, the system enabled continuous estimation of moth abundance over time, revealing site‐specific and temporal variation in moth activity relevant to IPM decision thresholds. By substantially reducing manual inspection effort while maintaining biologically meaningful population estimates, this approach offers a practical and scalable tool for enhancing stored‐product pest surveillance. The results support the feasibility of integrating automated image analysis into routine monitoring workflows to improve responsiveness and efficiency in postharvest pest management.

Japanese beetle, Popillia japonica Newman, is an invasive species that attacks many field and ornamental crops. Intercropping soybean with sorghum is suggested as a strategy to reduce the abundance of P. japonica throughout soybean fields. The mechanism by which this affects P. japonica is unknown but may arise from a difference in the host plant compounds emitted by the intercropped plants because P. japonica responds to olfactory cues. In this study, we investigated a semiochemical-based mechanism for the behavioral response of P. japonica to intercropping soybean with sorghum by (1) evaluating P. japonica behavioral responses to solvent extracts from monocropped soy, intercropped soy, and a mixture of soy and sorghum extracts in no-choice video-tracking and preference in a release-recapture dual-choice assay to host stimuli from plants; and (2) applying solid-phase microextraction (SPME) in conjunction with gas chromatography coupled with mass spectrometry (GC-MS) to characterize the semiochemical profiles of each extract. We found unique semiochemical profiles among our treatments, with 1-octen-3-ol and 1-octanol characteristic of monocropped soybean and dodecane-1-iodo primarily in sorghum extracts. Nevertheless, our treatments did not significantly affect movement or orientation by P. japonica compared to controls, nor did conspecifics exhibit a significant preference for any of the treatments in a dual-choice assay at a local scale. Therefore, if intercropping soybean with sorghum significantly affects the behavior of P. japonica in the field, it may occur at a different scale, or in response to non-olfactory stimuli (e.g., visual, habitat, or landscape cues) rather than semiochemical cues.

The invasive larger grain borer (Prostephanus truncatus) is a major pest of stored maize and threatens to expand its range under climate change. With the phase-out of methyl bromide and increasing resistance to phosphine, the most commonly used fumigant, there is a need for alternative management tactics. Here, we present an evaluation of the effectiveness of 2 types of insecticide-incorporated nets (0.4% deltamethrin, D-Terrence, Vestergaard, Lausanne, Switzerland; and 0.34% alpha-cypermethrin, Carifend, BASF Ag, Ludwigshafen, Germany) against adults of P. truncatus. To do this, we evaluated mortality in Petri dishes that had been lined with the 2 netting types. Netting of both types with no insecticide treatment served as the control. Twenty adults were placed into each dish, and insects were exposed for 60, 90, 120, 240 min, 1, 3, and 5 d. Mortality was immediately measured at the end of the exposure time, and delayed mortality after exposure to a clean food source was then evaluated after 7 d. Both long-lasting insecticide-incorporated netting types were effective for controlling P. truncatus. Carifend was 4.6 times more effective than the control, and D-Terrence was 8 times more effective than the control in terms of mortality. Overall, D-Terrence provided better efficacy in terms of mortality and a quarter fewer adults alive after 7 d with supplemental food compared to Carifend. Our study highlights the effectiveness of insecticide-incorporated nets as an alternative pest management tactic.

Theocolax elegans (Hymenoptera: Pteromalidae) is a potential postharvest biocontrol agent whose host range includes Sitophilus oryzae (Coleoptera: Curculionidae) and Rhyzopertha dominica (Coleoptera: Bostrichidae). Both host species are cosmopolitan and destructive pests of bulk wheat. In addition, either species could be used when mass rearing T. elegans. The Hopkins-Host Selection principle suggests the natal host environment (e.g., the habitat in which a wasp emerges from a pupa) may influence the semiochemicals an organism utilizes when foraging for oviposition sites. Thus, later efficacy may be impaired if important semiochemicals are lost from the foraging repertoire of T. elegans. In order to investigate the impact of natal host environment on the behavioral response of T. elegans to potential hosts, we reared T. elegans on either S. oryzae or R. dominica for multiple generations. We then evaluated the orientation and taxis of T. elegans to six treatments: S. oryzae, R. dominica, damaged grain + S. oryzae, damaged grain + R. dominica, damaged grain + insects from the natal environment, or an undamaged control. We found T. elegans reared on R. dominica most preferred damaged grain from R. dominica in a four-way olfactometer, which was 4.2-fold more often chosen than S. oryzae individuals alone. Treatments containing R. dominica were differentiated from others based on headspace volatiles while S. oryzaeinfested grain generally overlapped with uninfested grain. Both rearing host and subsequent foraging host affected efficacy of T. elegans released in a pilot-scale elevator. Wasps appeared most effective in suppressing grain damage by 35-38 % when reared on R. dominica and foraging for R. dominica compared to S. oryzae-reared wasps that only reduced damage by 1-18 %. Sitophilus oryzae-reared wasps only effectively foraged on hosts up to 0.5 m, while R. dominica-reared wasps foraged successfully up to 4 m. Overall, we found that the natal host and chemical cues significantly affected taxis and foraging by T. elegans, suggesting that careful attention should be paid to the mass rearing procedure for this parasitoid.

The majority of long-lasting insecticide-incorporated nets use alpha-cypermethrin or deltamethrin after harvest. However, there is interest in including long-lasting insecticide nets in integrated pest management programs at food facilities with new active ingredients against stored product insects. In this study, two impregnated nets, one with etofenprox and one with permethrin, were tested against adults of four stored product insects, that is Prostephanus truncatus (Horn), Sitophilus zeamais Motschulsky, Tribolium castaneum (Herbst), and Sitophilus granarius (L.). Among the tested species, S. granarius was the most susceptible, while in most cases, there were no differences in the efficacy level between the two nets. Short exposures resulted in immediate knockdown of all species, while increasing exposure to the nets decreased knockdown but increased adult mortality. When all adults were removed from the treated substrate and were transferred to untreated dishes, previous exposure to both nets caused more than 90% of delayed mortality 3 or 7 d later for S. granarius and S. zeamais. Our data underline the efficacy of impregnated nets with new active ingredients and their potentials for further use in stored product protection strategies.

Eucosma giganteana (Riley) (Lepidoptera: Tortricidae) is a specialist pest on Silphium spp. including Silphium integrifolium. This pest is currently one of the major limiting factors to the development and commercialization of S. integrifolium in Kansas as a more sustainable oilseed alternative within its native range. One of the factors making E. giganteana difficult to manage is the lack of knowledge about when pest management tactics should be applied for maximum effect. To aid with proper timing, our objectives were to determine a lower activity threshold, then use it to develop a growing degree day model to estimate important phenological events in the life history of adult E. giganteana in the field. In addition, we found a good fit between the actual phenological events for E. giganteana from 2020, 2023, and 2024 and the predicted phenological events from trapping data collected in 2019 in Salina, Kansas. The lower activity threshold was determined to be 17 °C using a series of environmental chamber experiments with overwintering E. giganteana larvae. Furthermore, we found a significant correlation between predicted growing degree days for phenological events in 2019 and the actual degree day measurements for those events in subsequent years. Finally, the model was able to accurately predict adult E. giganteana emergence in the field during 2024. We anticipate the model will continue to provide accurate predictions for the coming years, which would allow for improved timing of pest management practices for E. giganteana to be implemented.

ABSTRACTLong‐lasting insecticide‐incorporated netting (LLIN) can intercept insects and has shown promise for pest management before and after harvest in agriculture. Understanding how to incorporate LLIN into existing integrated pest management (IPM) programs, with other commonly used tactics like residual contact insecticides, can significantly enhance IPM programs at food facilities. In this study, we assessed whether LLIN (0.34% alpha‐cypermethrin, BASF) may enhance the effects of residual contact insecticides such as Centanyl EC (Central Life Sciences), active ingredient (a.i.) deltamethrin and Evergreen (McLaughlin Gormley King Co.), a.i. natural pyrethrins against Tribolium castaneum and Rhyzopertha dominica. We recorded their dispersal and progeny production in treatments with LLIN alone, deltamethrin or pyrethrins alone, LLIN + insecticide, or no treatment (positive control). We demonstrated the use of both LLIN and residual insecticide with either deltamethrin or pyrethrins reduced adult insect dispersal to the food sources compared to the control, but only increased control of progeny production marginally by 8%–19%. LLIN alone was highly effective in reducing progeny production of T. castaneum by 40% compared to the positive control. Importantly, pyrethrins did not cause significant direct mortality or prevent progeny production when used alone against T. castaneum. However, the combined use of pyrethrins with LLIN showed an enhanced efficacy against the insect. Together, the combined use of LLIN and the residual contact insecticides evaluated in our study may have some benefits over using residual contact insecticide alone to manage stored product insects.

The foundation of many postharvest integrated pest management (IPM) programs is proper sanitation. However, there may be deviations from this due to the effort, time, and cost required to keep a facility clean. Long-lasting insecticide-incorporated netting (LLIN) has been used successfully to augment post-harvest IPM programs, but has not yet been investigated for its role in supporting sanitation. Here, we investigated the use of LLIN to spot treat spillage and how food dust deposition may alter LLIN efficacy against Tribolium castaneum and Rhyzopertha dominica. After immersing 0.34 % alpha-cypermethrin LLINs in flour, we found no significant changes in adults of both species classified as alive, affected, and dead compared to undipped LLINs. We found slightly more recovery by T. castaneum after exposure to 0.4 % deltamethrin LLIN in the presence of food dust compared to when it was absent, but there was no effect on recovery for R. dominica. When a layer of LLIN was used to cover spillage, we found statistically equivalent numbers of affected and dead individuals induced compared to when spillage was absent. After holding spillage for 6 weeks, no larvae and 87 % fewer pupae were produced by T. castaneum after exposure to a layer of alpha-cypermethrin LLIN for 48 h, compared to netting without insecticide. Finally, we found a 2.5 cm strip of LLIN sufficiently impeded the dispersal of R. dominica on a site of spillage, but this was not the case for T. castaneum. Overall, these results suggest the use pattern for LLIN could be expanded, and that food dust will minimally affect LLIN efficacy against stored product insects, most likely due to the high concentration of the active ingredient in LLIN.

Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), and Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) are 3 important stored product pests of maize, but there has been little work evaluating how they vector microbes. While there has been some work assessing the microbial ecology of S. zeamais, none has directly assessed whether they transfer microbes to new food patches. Thus, we evaluated the ability of both species to vector microbes when given the opportunity to forage on sterilized potato dextrose agar dishes after a 0, 24, or 72 h dispersal period in a sterilized container. We subsequently photographed the dishes at 3 and 5 d after introduction and quantified the microbial growth using ImageJ. In addition, we isolated unique morphotypes of fungi, extracted DNA and amplified the internal transcribed spacer 5/4 intergenic spacer region, then sequenced to determine fungal identity. We found that 3 species readily vectored several plant pathogenic microbes, including 21 taxa from more than 11 genera, notably Aspergillus spp. Increasing dispersal period (0, 24, 72 h) resulted in a third less microbial growth (mean microbial growth or mean greyscale value from 0 to 255) by S. zeamais after 72 h, while for P. truncatus it resulted in a 2.7-fold increase in microbial growth. Dispersal by S. zeamais (0, 24, 72 h) resulted in 6.6-fold more microbial growth than dispersal by P. truncatus. There was 1.5- to 3.7-fold more microbial growth after 5 d than 3 d by each species. This research has important implications for food safety in the postharvest environment, especially for maize production, storage, and processing.

Understanding the combined contribution of insects and microbes to conditions in a grain mass is particularly relevant for pest management programs in bulk storage. There are important and strong interactions between Sitophilus oryzae (L.) and stored product fungi, especially Aspergillus flavus Link. The aims of this study were to determine how the introduction of S. oryzae, A. flavus, or both in a grain mass affected (i) the fitness of S. oryzae, and (ii) the abiotic conditions in a grain mass. Containers with 300 g of wheat were established with no insects or added microbes, 75 mixed-sex S. oryzae adults only, 11.6 g of A. flavus-inoculated grain only, or both, and dataloggers were placed in the masses to record temperature and relative humidity every 5 min. After 60 d, progeny were counted, and grain moisture was also measured. Although mean temperature was not consistently altered in the presence of A. flavus or S. oryzae, the combined inoculation of A. flavus and S. oryzae in a grain mass consistently elevated relative humidity by 7% to 8%. The presence of A. flavus or S. oryzae consistently elevated grain moisture from 10.8% prior to the experiment to about 13%. Importantly, there were 203-fold more F1 progeny produced by S. oryzae when A. flavus was present compared to when it was absent in a grain mass, possibly indicating a mutualistic relationship. Our work adds to the growing body of literature suggesting that insects and microbes should be managed in concert at food facilities.

The khapra beetle, Trogoderma granarium, is a stored product pest of global concern, readily transported with cargo and reported in over 60 countries, several of which have spent millions in USD to eradicate populations. Despite the profound risk to stored grain commodities, nothing is known about the potential future distribution of species. We utilize MaxEnt and two datasets representing (1) only the historical range and (2) all global locations where it currently is or was established, even if later eradicated, to model areas of suitability under current future climatic conditions under low and high climate change scenarios at close (2040) and distant (2080) time points. The potential distribution using historical data was much reduced compared to the combined model; consequently, all established localities, even if eradicated, change model outcomes and are vitally important when building models. An increase of high potential suitability (> 75% suitable) is projected with greater time and climatic scenarios, primarily in North America and Europe, which have previously eradicated T. granarium. These results call for greater surveillance to prevent T. granarium expansion to inland areas with high grain production and storage where devastating losses would occur.

Management of the brown marmorated stink bug, Halyomorpha halys (Stål), using attract-and-kill (AK) strategies in orchard crops has resulted in reduced pesticide inputs and the reestablishment of integrated pest management programs but also increased labor inputs and damage in pheromone-baited AK trees. Here, we re-tool previously developed AK practices for H. halys management using long-lasting insecticide netting (LLIN) as a low-input, effective killing agent. Simple LLIN AK stations were evaluated for efficacy compared with grower standard practices when hung directly on orchard perimeter fruit trees, hung on posts near, but not touching perimeter trees, and placed outside the orchard perimeter in commercial Mid-Atlantic apple orchards from 2017 to 2019. Treatments in which LLIN stations were attached to or hung near perimeter trees were equivalent to grower standards in terms of H. halys injury. In commercial pear orchards in Washington State in 2018 to 2020, efficacies of several LLIN station designs were evaluated as supplements to grower standard practices. A novel LLIN station design, referred to as the poncho trap, consistently caught nearly 3-fold more H. halys compared to a simple post-deployed “ghost trap” design when installed outside orchard perimeters. However, only LLIN stations mounted directly to perimeter trees provided statistically significant reductions in fruit damage. Our overall findings underscore the importance of positioning the pheromone lure, host plant (fruit tree), and LLIN in close proximity for successful AK H. halys management. Results also indicate that poncho trap LLIN fabric flaps could be integrated into near-mounted LLIN stations to further increase efficacy.

Trogoderma granarium, or khapra beetle, is a quarantined pest with a history of interceptions in countries where it is excluded. Long-lasting insecticide-incorporated netting (LLIN) may be able to provide additional quarantine security against this pest as a strategy for high-risk commodities. The aims of this study were to evaluate 1) direct lethality, and 2) sublethal effects of exposure to two LLINs on semiochemical-mediated foraging and movement by T. granarium. Direct lethality was examined on larvae after a 5- or 60-min exposure to control netting (without insecticide), a 0.34% alpha-cypermethrin (Carifend, BASF), or 0.4% deltamethrin LLIN (D-Terrence, Vestergaard, Inc.) over 168 h. Sublethal changes in movement were evaluated immediately after a 5-min exposure. Finally, semiochemical-mediated foraging was evaluated 24-h after LLIN exposure by larvae in a release-recapture assay using pitfall traps baited with either no stimulus, food cues, or the sex pheromone for T. granarium. The recovery of larval T. granarium dramatically rose and peaked 72-168 h after exposure to LLINs, while the percentage of alive individuals in the control remained consistently high. Larvae spent 6-10% more time in low acceleration and not moving after exposure to alpha-cypermethrin and deltamethrin LLIN compared to the control netting. There was a 6.6-fold higher capture of larvae in traps after exposure to control compared to deltamethrin netting. Elevated response to food cues was suppressed after exposure to LLIN. Overall, there is evidence of significant impacts of LLIN on T. granarium, but high recovery after short exposures and subsequent unresponsiveness to pheromone-baited traps, which are critical for species detection, suggest limitations for using LLIN in management for T. granarium.

Stored grain pests cause significant economic losses during cereal grain storage. Insecticides have long been central to pest control; however, growing concerns over resistance, environmental harm, and human health demand alternative strategies. Diatomaceous earth (DE) treatments are a safe, eco-friendly alternative to insecticides, although their efficacy depends on the temperature, humidity, dose, and insect species. This study assessed the insecticidal effects of two natively-sourced raw (Ankara and Aydin) and one commercial (Silico-Sec) DE treatments against the key pest species Rhyzopertha dominica (F.) and Sitophilus granarius (L.) on stored wheat. Five doses (0, 250, 500, 750, and 1000 ppm) of each DE treatment were tested under two temperatures (25 °C and 30 °C) and two humidity levels (40% and 60%). Mortality was assessed at 7, 14, and 21 days after treatment (DAT). All DE treatments caused higher mortality in S. granarius than R. dominica. The highest mortality occurred in S. granarius at 30 °C and 40% RH with the highest dose. Aydin DE was most effective, but did not reach 100% mortality in S. granarius by 21 DAT. In contrast, it caused 100% mortality in R. dominica under the same conditions. There was no F1 progeny produced by surviving individuals of both species. Given the similarity of the environmental conditions to the optimal conditions for DE efficacy present in Turkish storage facilities, natively sourced Aydin DE is a promising control option.

BACKGROUND:To date, prior research on the biological control of stored products has focused on the direct consumptive effects of parasitoids and predators. However, in other systems, trait-mediated indirect interactions or nonconsumptive effects have been shown to be as or more important in maintaining the suppression of pest populations. Thus, in this study, our aim was to evaluate the effect of the parasitoid, Theocolax elegans, the predator community around food facilities, and their associated chemical cues on the foraging behavior of Sitophilus oryzae and Rhyzopertha dominica. RESULTS:We evaluated consumptive predation of a variety of insect and arachnid predators on S. oryzae as well as effects on the foraging behavior of S. oryzae and R. dominica in a series of movement assays after exposure to adult T. elegans, headspace extracts from T. elegans or gryllids, and a facsimile gryllid model to determine potential nonconsumptive effects. We found the headspace from T. elegans colonies to be distinct from other treatments. The strength of nonconsumptive effects appeared to be greater after exposure to T. elegans adults compared to other predators or extracts. The presence of T. elegans in a block led to a 48-58% reduction in distance moved and 40-56% reduction in instantaneous velocity for the control and wheat treatments by S. oryzae and R. dominica compared to when wasps were absent. Rhyzopertha dominica exhibited 73% reduced frequency of entering the zone with wheat when adult T. elegans was present. CONCLUSIONS:We conclude that nonconsumptive effects may result in alterations in behavior by stored product insects, but these effects may vary by the coevolutionary relationship between the natural enemy and pest. Published 2025. This article is a U.S. Government work and is in the public domain in the USA.