Assessing the efficacy of predatory arthropods in controlling Asian citrus psyllid (Hemiptera: Psyllidae) eggs

Asian citrus psyllids Diaphorina citri Kuwayama (Hemiptera: Psyllidae) (ACP) and huanglongbing (HLB) continue to pose critical threats to the US citrus industry. Augmentative biocontrol is a possible alternative to insecticides, especially for organic citrus production. While considerable effort has been spent on identifying natural enemies of ACP immatures, their efficacy against eggs concealed in unopened shoots remains understudied. We evaluated 4 commercially available predators for their predation on ACP eggs: minute pirate bug Orius insidiosus (Say) (Hemiptera: Anthocoridae), green lacewing Chrysoperla rufilabris (Burmeister) (Neuroptera: Chrysopidae), mealybug destroyer Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), and predatory mite Amblyseius swirskii Athias-Henriot (Mesostigmata: Phytoseiidae). Predator efficiency was quantified on egg-infested shoots in laboratory assays using (24-48 h) and whole-plant cages (2-4 d). All predators except A. swirskii significantly reduced egg numbers on shoots. Lacewings, mealybug destroyers, and minute pirate bugs achieved 94%, 76%, and 68% suppression, respectively, in the laboratory. In whole-plant cage conditions, lacewings and mealybug destroyers provided 97% and 93% egg suppression, respectively, while O. insidiosus reduced egg density by 73%. Functional response modeling revealed high consumption capacity in C. montrouzieri and C. rufilabris, each exceeding 100 eggs per exposure period, while O. insidiosus averaged 65 eggs. Together, these findings indicate that targeting ACP eggs with lacewings or mealybug destroyers may substantially enhance sustainable psyllid management and support long-term HLB mitigation in citrus groves.