Field efficacy of autodissemination and foliar sprays of an entomopathogenic fungus, Isaria fumosorosea (Hypocreales: Cordycipitaceae), for control of Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae)

Authors: CHOW, ANDREW - Texas A&M University; Dunlap, Christopher; Jackson, Mark; AVERY, PASCO - University Of Florida; Patt, Joseph - Joe; SETAMOU, MAMOUDOU - Texas A&M University

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/2/2018
Publication Date: 9/26/2018
Citation: Chow, A., Dunlap, C.A., Jackson, M.A., Avery, P.B., Patt, J.M., Setamou, M. 2018. Field efficacy of autodissemination and foliar sprays of an entomopathogenic fungus, Isaria fumosorosea (Hypocreales: Cordycipitaceae), for control of Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae). Journal of Economic Entomology. 111:2089-2100. DOI: 10.1093/jee/toy216.
DOI: https://doi.org/10.1093/jee/toy216

Interpretive Summary: Citrus greening is a serious threat to the citrus industry in the United States. This disease is vectored by an insect, the Asian citrus psyllid. Non-commercial residential citrus trees create a reservoir where the insect pest can hide and reproduce. This study tests non-chemical control methods to control the insects in neighborhood scale studies. The results and methods are able to provide some levels of control to the serious problem. This research benefits orchard growers and consumers that utilize citrus products.

Technical Abstract: Autodissemination and foliar sprays of PFR-97™ (Certis, USA) microbial insecticide, based on blastospores of the entomopathogenic fungus Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae), were evaluated for control of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), on residential citrus. Seasonal field trials on dooryard trees in South Texas evaluated: 1) PFR-97 infectivity on autodisseminators (dispensers) deployed up to three weeks on grapefruit trees; 2) psyllid control on orange trees by dispensers or sprays; 3) psyllid control on lime or grapefruit trees by dispensers, sprays, or dispensers and sprays; 4) psyllid infection on trees with dispensers and also nearby trees. Decline in blastospore infectivity was not significantly different among dispensers during fall, winter, or spring and decreased by 30% after 1 d, 59% after 7 d, 81% after 14 d, and 100% after 21 d. Dispensers or sprays were equally effective for psyllid control on heavily infested lime trees thru fall to spring and reduced mean reproduction (cumulative egg counts) by 90% and mean attack intensity (cumulative psyllid-days) of adults by 77% or of nymphs by 82%. Dispensers or sprays were also equally effective for psyllid control on less heavily infested lime trees thru spring to mid-summer or on orange or grapefruit trees thru fall to winter. Very light infestations on grapefruit trees thru spring to mid-summer were not significantly reduced by dispensers or sprays. Combining dispensers and sprays did not improve psyllid control. Adult psyllids infected by Isaria were recovered from trees with dispensers and also trees located 3-4 m away.