Oviposition behavior and survival of Tamarixia radiata (Hymenoptera: Eulophidae), an ectoparasitoid of the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), on hosts exposed to an entomopathogenic fungus

Authors: CHOW, ANDREW - Citrus Center; Dunlap, Christopher; Jackson, Mark; FLORES, DANIEL - Animal And Plant Health Inspection Service (APHIS); Patt, Joseph - Joe; SETAMOU, MAMOUDOU - Citrus Center

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2016
Publication Date: 7/19/2016
Publication URL: http://handle.nal.usda.gov/10113/5927833
Citation: Chow, A., Dunlap, C.A., Jackson, M.A., Flores, D., Patt, J.M., Setamou, M. 2016. Oviposition behavior and survival of Tamarixia radiata (Hymenoptera: Eulophidae), an ectoparasitoid of the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), on hosts exposed to an entomopathogenic fungus. Journal of Economic Entomology. 109:1995-2005. doi: 10.1093/jee/tow164.

Interpretive Summary: In the current study, Texas A&M University researchers in collaboration with ARS and APHIS researchers, examined the impact of a beneficial insect-killing fungus on a beneficial insect species that preys upon an insect pest (Asian citrus psyllid). Both beneficial insect-killing fungi and predator insects are commonly employed to control insect pests. However, little is known about how these pest control options impact each other. This study shows at times early in the beneficial insects’ life cycle that they are susceptible to the fungus used to kill insect pests. This study provides guidance all how best deploy these two control options in an integrated pest management system for maximum effectiveness. This research directly benefits farmers, extension agents and researchers trying to control the Asian citrus psyllid and its vectored disease (citrus greening) using an integrated approach.

Technical Abstract: Antagonistic interactions between the nymphal parasitoid, Tamarixia radiata Waterston (Hymenoptera: Eulophidae), and the ARSEF 3581 isolate of the entomopathogenic fungus, Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae) could disrupt biological control of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Three interactions were evaluated: (1) parasitoid survival if parasitized hosts were exposed to ARSEF 3581 blastospores before or after host mummification; (2) parasitoid survival if mummies containing larva or pupa were exposed to ARSEF 3581 hyphae; (3) parasitoid oviposition on infected hosts with visible hyphae and infected hosts without hyphae. Exposure of live T. radiata-parasitized hosts to blastospores reduced host mummification by 50 % and parasitoid emergence by 85 %. However, parasitoid emergence was not affected by exposure of mummies to blastospores. Exposure to hyphae reduced parasitoid emergence by 80 % from mummies that contained larva but did not affect emergence from mummies that contained pupa. Female parasitoids oviposited on infected hosts without hyphae but not on infected hosts with visible hyphae. Our findings suggest that I. fumosorosea could detrimentally affect the oviposition, abundance, and reproductive success of T. radiata, if both natural enemies are simultaneously deployed for biological control of D. citri. However, because T. radiata is mostly active during periods when D. citri nymphs are present on expanding flush shoots, a temporal separation in deployment of the fungus and parasitoid could reduce antagonism between them and enhance their efficacy against D. citri.