Field evaluation of attract-and-kill devices for control of Asian citrus psyllid (Hemiptera: Liviidae) in urban landscapes

Abstract

The Asian citrus psyllid, Diaphorina citri (Kuwayama) (Hemiptera: Liviidae), vector of huanglongbing, is uncontrolled in urban and unmanaged citrus refugia, from where psyllids can infest commercial groves. Attract-and-kill devices (AKDs) may be a practical tool for controlling D. citri in these areas. We tested 2 AKDs, the yellow perforated cylinder AKD and the black screen AKD in which the killing agents (yellow sticky card traps) were placed inside the devices to prevent contact by non-target organisms. Experiments were conducted in laboratory cage bioassays and in an orange jasmine (Murraya paniculata; Rutaceae) hedge. Two scent attractant mixtures (myrcene, gamma-terpinene, and acetic acid; acetic and formic acid) were sprayed onto the yellow sticky card traps as a means of increasing the attractiveness of the AKDs. Despite promising results in laboratory assays, neither scent increased psyllid capture in the AKDs under field conditions. Enlarging the diameter of the entry holes (from 6 to 20 mm) in the yellow perforated cylinder AKD increased psyllid capture but also permitted entry by small reptiles. Unscented black screen AKDs caught over twice as many psyllids as unscented yellow perforated cylinder AKDs, but still caught juvenile reptiles. These AKDs were highly effective in tracking psyllid populations in the hedge. Once adjustments to reduce non-target captures are made, these AKDs should be more acceptable to homeowners and consumers than current insecticidal controls. This acceptance, in turn, could make them a valuable and sustainable tool for area wide management strategies aimed at reducing the spread of huanglongbing.