Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 16, 2011
Publication Date: December 1, 2011
Citation: Hunter, W.B., Avery, P.B., Pick, D., Powell, C.A. 2011. Broad sprectrum potential of Isaria fumosorosea on insect pests of citrus. Florida Entomologist. 94:1051-1054.
Interpretive Summary: The entomopathogenic fungus Isaria fumosorosea (Ifr), holds some promise as a management tool for a number of citrus pests including Asian citrus psyllid, Diaprepes root weevil, leafhoppers, and aphids. These insects were susceptible to Ifr under laboratory conditions. Psyllids appeared most susceptible with the earliest mortality 2 days post-treatment and 100 percent mortality by day 8. During this time period, psyllid feeding was reduced. Leafhopper adults showed increasing mortality by day 3 with 100 percent at 15 days post treatment. The glassy-winged sharpshooter leafhopper showed similar rates of mortality during the same time period, with 100 percent at 15 days post treatment. All aphids treated with Ifr died by 15-20 days post treatment. Ifr was effective against Diaprepes root weevil, although 100 percent mortality of treated weevils did not occur until 35 days post-treatment. Ifr may provide an additional biological control agent to be used in current pest reduction programs.
Use of entomopathogenic fungi, Isaria fumosorosea, Ifr, =Paecilomyces fumosoroseus, successfully increased insect pest mortality. Spraying the Ifr containing product, PFR97 TM, on citrus seedlings was used to screen efficacy for the management of Asian citrus psyllid, Diaphorina citri; glassy-winged sharpshooter leafhopper, Homalodisca vitripennis; citrus aphids, Toxoptera citricida and a coleopteran, Diaprepes root weevil. The three hemipteran insects (psyllid, leafhopper, aphid) and coleopteran all were susceptible to infection. Psyllids appeared most susceptible to PFR97 with the earliest mortality observed 2 days post-treatment, with 100 percent mortality by day eight. During this time period, psyllid feeding was reduced as evidenced by the reduction of honeydew droplets. Leafhopper adults showed increasing mortalities by day 3 with 100 percent at 15 days post treatment. The glassy-winged sharpshooter leafhopper nymphs showed similar rates of mortalities during the same time period, with 100% by 15 days post treatment. Aphids showed 100 percent mortality at 15-20 days post treatment. Within all hemipteran control groups, mortality was 3 percent or less over the same time period. For the coleopteran weevil which has a larger body size, thicker cuticular layer control groups had 13 percent mortality by 15 days post-treatment reaching a maximum of 33 percent at 35 days, while fungal treated weevils showed 100 percent mortality at 35 days post exposure. The Ifr spray product, PFR97 TM, demonstrated potential to reduce citrus insect pests and may provide an additional biological control agent programs.