UC Davis

Monitoring and sampling insects provide critical data for decision making in integrated pest management strategies and plant breeding. Manual sampling and monitoring methods may be biased by interactions between the method, the cropping system, and the size and behavior of the target insects, as well as circadian and seasonal dynamics. These methods may also be limited by the quantity of time and labor required for collection and processing. Novel autonomous insect sensors resolve some of these limitations but may present new challenges. Understanding the limitations and biases of established and novel methods will improve the quality of available data. This study examines the biases of circadian flight activity and seasonal dynamics on water trap, vacuum, and autonomous sensor data with a focus on the crop pest, the Western Tarnished Plant Bug, Lygus hesperus (Hemiptera: Miridae Knight) in fields of Lima beans, Phaseolus lunatus. The study also includes sensor measurements of L. hesperus in a controlled laboratory environment. A strong multimodal circadian effect was observed in sensed and vacuumed L. hesperus. The laboratory results also revealed a similar pattern of daytime and crepuscular activity but lacked a midday activity peak observed in the field. Correlations were strong between total sensed insects and water trap data from over the course of the entire season, indicating that the novel autonomous insect sensor could be a good substitute for conventional monitoring methods. More research will be needed to determine the thresholds of sensed insect data that correspond with established measures for integrated pest management and breeding. Consideration of these biases will result in higher quality data that will be useful for advancing the development of insect resistant crop varieties and improving pest management.