Influence of shoot production on Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) populations in citrus

The Asian citrus psyllid (ACP) is an efficient vector of the bacterium Candidatus Liberibacter asiaticus that causes the devastating huanlongbing or citrus greening disease. Newly developing shoots are needed for oviposition and nymphal development; whereas adults can survive, but not reproduce, on mature leaves. Therefore, shoot production plays a vital role in the population dynamics, movement and management of psyllid. Young citrus trees produce shoots more frequently compared to mature trees and orange jasmine (Murraya paniculata) an ACP alternate host is thought to produce shoots more frequently than citrus. Young plants of orange jasmine and citrus treated or not with imidacloprid were tested for effects on psyllid populations in citrus. Shoots and psyllid populations were also monitored on young and mature citrus trees under natural conditions. Mature citrus trees were also pruned to induce new shoots and ACP numbers compared with unpruned trees by trapping adults with yellow sticky cards placed around the trees. Implications of results from these studies will be discussed in the context of psyllid management.