|Bray Bishop, Belinda|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2009
Publication Date: 11/25/2009
Citation: Yee, W.L., Lacey, L.A., Bray Bishop, B.J. 2009. Pupal Mortality and Adult Emergence of Western Cherry Fruit Fly (Diptera: Tephritidae) Exposed to the Fungus Muscodor albus (Xylariales: Xylariaceae). Journal of Economic Entomology. 102(6):2041-2047.
Interpretive Summary: Cherry fruit vly is a serious quarantine pest of commercial cherries in the Pacific Northwest. The fly is currently controlled using insecticides, but alternatives to use of insecticides alone for managing the fly are needed. Personnel at the USDA-ARS Yakima Agricultural Research Laboratory in Wapato, WA, are determining the effects of the fungus Muscodor albus on mortality of pupae and adult emergence of the fly. We found that volatiles from the fungus can cause significant mortality of the pupae and can also delay the emergence of adults. The results of this tudy are important in that they indicate there may be methods to manage the fly in addition to insecticide use, and that these methods need to be developed.
Technical Abstract: Western cherry fruit fly, Rhagoletis indifferens Curran, is a major pest of sweet cherry, Prunus avium (L.) L., that is conventionally controlled using insecticides. One alternative to the use of insecticides for fly control could be fumigation of the fly’s overwintering habitat using the fungus Muscodor albus Worapong, Strobel & Hess (Xylariales: Xylariaceae) in conjunction with reduced insecticide use. The fungus produces a mixture of volatile organic compounds (VOCs) that are biocidal for a wide variety of organisms. In this study, the main objectives were to determine the effects of M. albus VOCs on mortality of R. indifferens pupae and on adult emergence under laboratory conditions. In fumigation chamber experiments, a 14-d exposure of pupae in soil to VOCs caused 39.1% corrected pupal mortality, and exposure to VOCs for 7, 10, and 14 d reduced fly emergence by 44.2, 70.0, and 86.3%, respectively, relative to controls. In an experiment using plastic covers to retain VOCs in treated soil, a concentration of 1% M. albus formulation (fungus + rye grain) did not affect pupal mortality and fly emergence, but a concentration of 5% M. albus formulation caused 18.8% corrected pupal mortality and reduced fly emergence by 30.1% relative to the control. Larvae of R. indifferens that were dropped onto soil with 1% M. albus formulation were not affected by the fungus. Results indicate that prolonged exposure and high concentrations of M. albus VOCs can cause significant mortality of R. indifferens pupae in soil and delay adult emergence.