The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a serious threat to the U.S. citrus industry because it spreads huanglongbing (HLB), a bacterial and incurable citrus disease. The nymphal parasitoid, Tamarixia radiata Waterston (Hymenoptera: Eulophidae), has been extensively released for biological control of D. citri in South Texas since 2010 but provides insufficient control. An ‘attract-and-kill’ (AK) device was evaluated for its compatibility with T. radiata for suppression of D. citri on dooryard citrus. The AK device is visually attractive to D. citri adults because it is the same color as young citrus flush and kills individuals on contact with the toxicant beta-cyfluthrin. This study evaluated 1) lethality of AK devices to T. radiata adults under lab conditions; 2) efficacy of AK devices for year-round psyllid suppression on individual dooryard lemon trees; 3) discovery and parasitism of D. citri colonies by T. radiata on lemon trees with or without AK devices. Contact with AK devices for 5 s or more was lethal to adult parasitoids. Deployment of 20 AK devices per tree provided significant year-round suppression of D. citri on infested lemon trees and reduced mean attack intensity (cumulative psyllid-days) of adults by 66% and nymphs by 82%. Discovery and parasitism rates of D. citri colonies by T. radiata were similar on control trees and trees protected by AK devices. An AK device that targets adult psyllids could be used to effectively complement biological control of D. citri by T. radiata in residential landscapes.

Graphical Abstract