A new “walker” tool for efficient placement of Diaphorina citri (Hemiptera: Liviidae) on trees in mating behavior bioassays

The Asian citrus psyllid, Diaphorina citri Kuwayama, is a known carrier of the bacteria Huanglongbing. This bacteria, when transmitted by psyllids, is extremely lethal to citrus trees. Because of this fact, a significant amount of research has been conducted into the psyllid insect itself. At the CMAVE lab in Gainesville, Florida, bioassays are being actively run which analyze the possible interruption of vibrational calls between males and females during courtship. Before the tests can begin, it is important that the psyllids are independently settled on each leaf. Initially, our data collectors found that many psyllids jumped off during transfer to the leaf and refused to settle on the leaf surface. As a result, a walker tool was developed. This object is a dark tube that naturally encourages the psyllid to move up and towards the light. By allowing the psyllid to naturally move, rather than pushing it, it can be expected that the psyllids are more likely to settle comfortably onto the leaf surface. When compared with placement using a paintbrush, initial data has shown that the walker tool does reduce the time of placement and the number of psyllid escapes. The lower rate of psyllid jumps prevents researchers from losing several bugs, and therefore several data points, during setup. The walker tool also helps to ensure that the placed psyllids are less irritated on the leaf surface. The walker tool is a simple tool that can greatly improve the efficiency of psyllid bioassays.