A "walker" Tool to Place Diaphorina citri (Hemiptera: Liviidae) Adults at Predetermined Sites for Bioassays of Behavior in Citrus (Sapindales: Rutaceae) Trees

Abstract

A "walker" tool was developed to assist successful placement of Diaphorina citri Kuwayama (Hemiptera: Liviidae) adults at predetermined sites on citrus (Sapindales: Rutaceae) trees in behavioral bioassays. Use of the walker resulted in a significantly higher proportion of successful placements and a significantly lower number of jumps away from the predetermined site compared with the use of a brush, although on average it required an additional 108 s more than the 41 s required with the brush to complete a successful placement. Females and males performed similarly with both devices. Potentially, the walker is a useful placement tool under conditions where it is time and labor intensive to provide large numbers of insects with specific physiological characteristics for testing, e.g., when it is difficult to supply large numbers of D. citri adults of known sex, mating status, and age. Because phototaxis is commonly observed in psyllids, the walker may be of use also for bioassays with other economic pests such as Bactericera cockerelli (Šulc) (Hemiptera: Triozidae).