Spatial and temporal variation in stored-product insect pest distributions and implications for pest management in processing and storage facilities

Authors: Gerken, Alison; Campbell, James - Jim

Submitted to: Annals of the Entomological Society of America
Publication Type: Review Article
Publication Acceptance Date: 10/19/2021
Publication Date: 11/17/2021
Citation: Gerken, A.R., Campbell, J.F. 2021. Spatial and temporal variation in stored-product insect pest distributions and implications for pest management in processing and storage facilities. Annals of the Entomological Society of America. 115(3)239-252. https://doi.org/10.1093/aesa/saab049.
DOI: https://doi.org/10.1093/aesa/saab049

Interpretive Summary: Insect pests of stored grain and grain based products can infest products in facilities at any point along the supply chain after harvest. Post-harvest insects move throughout a facility searching for mates, food, and shelter and their movement and spatial distribution is also driven by movement of product, sanitation activities, and insecticide applications. Determining spatial distributions and population density of these insects provides important information to develop more targeted and cost-effective management programs. Monitoring data collected using traps to capture stored product insect pests has provided information on spatial distribution and movement patterns of stored product insect pests under a range of conditions: in bins of grain, grain elevator silos and their immediate environment, milling and processing facilities, commercial warehouses, and retail stores. In evaluating available data, we found few generalizable patterns, though we did identify key influences that may be leveraged to increase the impacts of future monitoring schemes. Species-specific locations of infestation were common among these stored product insect pests and seasonal variation was highly influential in population growth patterns. Competition among different species also drives spatial distributions and overlap in different species is limited. Vertical distribution of insects was common in bins, elevators, and silos. More insects were often found in the receiving and storage areas of mills and processing facilities and insects often migrated into facilities from surrounding natural reservoirs. Previously stored grain and spillage can also harbor long-term insect populations, which also reinforces the need for sanitation in and around stored grain products. Continued monitoring research will provide information to develop predictive tools which will use behavioral patterns to further our understanding of these insect pests within these unique facilities and circumstances.

Technical Abstract: Post-harvest insects colonize environments that are often buffered from environmental perturbations but susceptible to both sustained and stochastic human influences. Insect infestations can result in damaged or destroyed product, costing producers and retailers millions of dollars in lost product annually. Post-harvest insects move throughout a given space searching for mates, food, and shelter and their movement and spatial distribution is also driven by movement of product, sanitation activities, and insecticide applications. Determining spatial distributions and population density of these insects provides important information to develop more targeted and cost-effective management programs. Monitoring data collected using traps to capture stored product insect pests has provided information on spatial distribution and movement patterns of stored product insect pests under a range of conditions: in bins of grain, grain elevator silos and their immediate environment, milling and processing facilities, commercial warehouses, and retail stores. In evaluating available data, we found few generalizable patterns, though we did identify key influences that may be leveraged to increase the impacts of future monitoring schemes. Species-specific locations of infestation were common among these stored product insect pests and seasonal variation was highly influential in population growth patterns. Competition among different species also drives spatial distributions and overlap in different species is rare. Vertical distribution of insects was common in bins, elevators, and silos. More insects were often found in the receiving and storage areas of mills and processing facilities and insects often migrated into facilities from surrounding natural reservoirs. Previously stored grain and spillage can also harbor long-term insect populations, which also reinforces the need for sanitation in and around stored grain products. Continued monitoring research will provide information to develop predictive tools which will use behavioral patterns to further our understanding of these insect pests within these unique facilities and circumstances.