Jacqueline M. Maille

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.

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.

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.

Management of stored-product pests has historically relied on fumigation when pest populations become large. However, the ban of the fumigant methyl bromide and the ineffectiveness of other pesticides stress the need for alternative fumigants. Therefore, laboratory studies were conducted to evaluate the efficacy of ethanedinitrile (EDN) against different life stages of the mite Tyrophagus putrescentiae and to determine the sorption and desorption of EDN by dry-cured ham meat. The results showed that eggs were the most tolerant life stage to EDN fumigation, with an estimated LC₅₀ of 0.6 mg/L. Tyrophagus putrescentiae mixed life-stage colonies were controlled at 1.3 mg/L, and less than 0.05% of the population survived following treatment with 0.6 mg/L within 24 h at 25 °C. The free-headspace concentrations of EDN in fumigation chambers containing ham decreased by 97% of the initial concentrations applied (2.6 and 4.8 mg/L) after the 24 h fumigation period. The EDN sorption in ham followed the first-order kinetics, with half-life values of 5.0 and 4.9 h for 2.6 and 4.8 mg/L, respectively. The percentage losses of EDN per hour were calculated to be 12.8 and 13.2% at 2.6 and 4.8 mg/L, respectively. Our study indicates that EDN controls T. putrescentiae in the laboratory.

The Entomological Society of America (ESA) Student Debates is an annual student competition at the ESA Annual Meeting organized by Student Debates Subcommittee (SDS) members of the ESA Student Affairs Committee. In conjunction with the 2023 ESA Annual Meeting theme, ‘Insects and influence: Advancing entomology’s impact on people and policy’, the theme of this year’s student debate was ‘Addressing emerging issues in entomology’. With the aid of ESA membership, the SDS selected the following debate topics: (1) Should disclosure of artificial intelligence large language models in scientific writing always be required? and (2) Is it more important to prioritize honey bee or native pollinator health for long-term food security within North America? Four student teams from across the nation, composed of 3–5 student members and a professional advisor, were assigned a topic and stance. Over the course of 5 months, all team members researched and prepared for their assigned topic before debating live with an opposing team at the 2023 ESA Annual Meeting in National Harbor, Maryland. SDS members additionally prepared and presented introductions for each debate topic to provide unbiased backgrounds to the judges and audience for context in assessing teams’ arguments. The result was an engaging discussion between our teams, judges, and audience members on emerging issues facing entomology and its impact on people and policy, such as scientific communication and food security, that brought attention to the complexities involved when debating topics concerning insects and influence.

Understanding the ability of internal‐ and external‐infesting stored product insects to vector microbes is important for estimating the relative risk that insects pose to postharvest commodities as they move between habitat patches and in the landscape. Thus, the aim of the current study was to evaluate and compare the microbial growth in novel food patches at different dispersal periods by different populations of Sitophilus oryzae (e.g., internal‐infesting) and Lasioderma serricorne (e.g., external‐infesting). Adults of both species collected from laboratory colonies or field‐captured populations were either placed immediately in a novel food patch, or given a dispersal period of 24 or 72 h in a sterilized environment before entering a surrogate food patch. Vectored microbes in new food patches were imaged after 3 or 5 days of foraging, and microbial growth was processed using ImageJ while fungal species were identified through sequencing the ITS4/5 ribosomal subunit. We found that increasing dispersal time resulted in multiple‐fold reductions in microbial growth surrogate food patches by L. serricorne but not S. oryzae. This was likely attributable to higher mobility by S. oryzae than L. serricorne. A total of 20 morphospecies were identified from 13 genera among the 59 sequences, with a total of 23% and 16% classified as Aspergillus and Penicillium spp. Our data suggest that there is a persistent risk of microbial contamination by both species, which has important food safety implications at food facilities.

Flight behavior is an important component to understand in the context of pest management. However, because of their small size, little is known about the flight capacity of most stored-product insects, and when a flight has been assessed, it usually consists of a propensity for initiating flight. Despite a priori expectations of the importance of flight for moths, there are no data about the flight capacity and little on the flight behavior of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). As a result, the objective of the current study was to (i) characterize the baseline flight capacity of E. kuehniella and (ii) determine how flight capacity is affected by the presence of kairomonal, pheromonal, or no stimuli. We found adult E. kuehniella flew a mean of 24–34 km in a 24-h period, and the distance flown per bout increased from 91 to 207 m in the presence of pheromones but decreased to 41 m when food was nearby compared to a negative control. The total number of flight bouts was 1.6-fold higher in the presence of pheromone compared to the negative control, but E. kuehniella flew significantly slower with pheromone and food cues present, suggesting they may be exhibiting an optimal foraging strategy. Our data on flight capacity results in qualitatively and quantitatively different conclusions about flight than those conclusions formed if only flight initiation is considered. Overall, this novel information is useful for understanding the spread within facilities and in the landscape (between facilities), as well as parameterizing ecological modeling.

The storage mite Tyrophagus putrescentiae infests a wide range of food products including pet food. Control of this mite depends on chemical methods such as fumigation and spraying with insecticides. Methyl bromide was used as a fumigant for high-value stored products, especially to control mite infestation in dry-cured hams and cheeses, but it is now banned for most uses in many countries because of its atmospheric ozone-depleting effects. Effective alternatives to methyl bromide are needed to develop integrated pest management programs for this pest. Liquid smoke is a naturally derived flavoring and preservative with known antimicrobial properties. The objective of this study was to investigate the efficacy of liquid smoke preparations, with varying phenol and carbonyl concentrations and pH, on the survivability and orientation behavior of T. putrescentiae in a model semi-moist pet food. The mite survivability assays using liquid smoke-treated and untreated semi-moist pet food samples indicated that there was no difference among treatments (p > 0.05) for mite infestation and survival. Two-choice behavioral assays using semi-moist pet food cubes dipped in varying concentrations (0%, 0.3%, 1%, 5%, 10%, 25%, 50%, or 100% v/v) of liquid smoke preparations found that some of the liquid smoke preparations containing medium to high carbonyl content repelled the mites. In conclusion, liquid smoke did not kill or inhibit the mite population growth in semi-moist pet food. However, some liquid smoke fractions containing medium to high carbonyl content were repellent to mites and may retard mite infestation in stored semi-moist foods.

The ham mite Tyrophagus putrescentiae and the red-legged ham beetle Necrobia rufipes are harmful pests to several high-valued stored products. The regulatory phase-out of the fumigant methyl bromide necessitates the search for alternative fumigants. Propylene oxide (PPO) and ethyl formate (EF) were therefore evaluated in the laboratory for controlling these pests of dry-cured hams. Concentration–mortality studies at 25 °C of PPO and EF found that the mobile stages of the mites were very susceptible to low concentrations of 10 mg/L and less of each gas, while mite eggs were very tolerant and required 20 mg/L for PPO and 80 mg/L of EF for 100% mortality. Mixed life stage cultures of mites and beetles were treated for 24 h with either PPO or EF at 1× and 2× the estimated 99% lethal doses and confirmed effectiveness for controlling simulated pest populations. The sorptive properties of each gas in chambers with ham pieces, dog food kibbles, or fish meal were minimal for a reduction in mite toxicity when compared to treatments in empty chambers. There was no evidence that any desorbed gas occurred at a level toxic to mite eggs in any of the fumigated commodities. These fumigation studies with ham pests support further work with PPO and EF on any changes in the sensory quality of dry-cured hams for human taste and for commercial-scale fumigations toward regulatory approval.

The 2022 student debates of the Entomological Society of America (ESA) happened during the Joint Annual Meeting of the Entomological Societies of America, Canada, and British Columbia in Vancouver, BC, and addressed entomological aspects beyond research and education. The Student Debates Subcommittee of the ESA Student Affairs Committee and the participating student team members communicated for 8 months and prepared for the debates. The theme of the ESA meeting in 2022 was “Entomology as inspiration: Insects through art, science, and culture”. There were 2 unbiased speakers who introduced the debate topics as well as 4 teams who debated the following 2 topics: (i) Is forensic entomology viable in criminal case investigations and court cases today? and (ii) Are insects being treated ethically in scientific research? The teams prepared for about 8 months, debated their arguments, and shared their thoughts with the audience. The teams were judged by a panel and the winners were recognized at the ESA Student Awards Session during the annual meeting.