Seasonal and lifecycle changes in behavior affect the trapping efficiency of an insect vector, Circulifer tenellus (Hemiptera: Cicadellidae)

Abstract

Accurate sampling of pests is the foundation of pest management. Choosing the best trap for pest monitoring can be complex, however, because trap performance is affected by pest preferences and behaviors. Moreover, preservation of DNA in traps is a consideration when insect specimens are used in molecular assays, such as the detection of insect-borne pathogens. We assessed the efficiency of 2 trap designs and 2 trap placements on the capture of beet leafhopper, Circulifer tenellus (Baker) (Hemiptera: Cicadellidae), vector of “Candidatus Phytoplasma trifolii” and Beet curly top virus. Trap designs included standard yellow sticky cards and 3D-printed traps that capture insects directly in a DNA preservative. We found that yellow sticky cards captured more adults than did 3D-printed traps during summer months but captured fewer adults during autumn when leafhoppers move to overwintering sites. 3D-printed traps captured more nymphs than sticky cards, regardless of season, and traps hung at ground level captured more nymphs and adults compared to traps at 1-m height. Contrary to predictions, we did not find differences between trap types in the molecular detection of Ca. P. trifolii or Beet curly top virus, perhaps because 3D-printed traps captured few leafhoppers during summer when the pathogen rates were highest. Our results suggest behavioral differences in C. tenellus trap preference based on seasonality and life stage and underscore the importance of understanding insect behaviors when choosing trap designs for pest monitoring as well as for properly interpreting trap capture data.