Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2011
Publication Date: 12/20/2011
Citation: Cossentine, J., Jaronski, S., Thistlewood, H., Yee, W.L. 2011. Impact of metarhizium brunneum petch clavicipitaceae (Hypocreales) on pre-imaginal Rhagoletis indifferens (Diptera: Tephritidae) within and on the surface of orchard soil. Biocontrol Science and Technology. 21:1501-1505. Interpretive Summary: The western cherry fruit fly damages sweet cherry fruit and is a major concern for cherry growers in the western U.S. Personnel at the USDA-ARS Yakima Agricultural Research Laboratory in Wapato, WA and at other locations examined mortality of cherry fruit fly in soil treated with the pathogenic fungus Metarhizium brunneum. It was found that the fungus killed over 80% of immature stages of the fly. The susceptibility of immature cherry fruit flies to the fungus when entering soil indicates that orchard floor management of this pest may be possible.
Technical Abstract: When last instar laboratory-reared Rhagoletis indifferens were allowed to pupate within non-sterile orchard soil containing Metarhizium brunneum isolate F52 conidia, a dose related proportion died from developmental abnormalities and mycosis. Similarly, when last instar larvae entered soil that was surface-treated with 4.5 x 106 M. brunneum conidia cm-2, over 80 % of the pupae died of developmental abnormalities. Metarhizium was isolated from some of the aseptically dissected pupae removed from the treated soils. The susceptibility of laboratory reared R. indifferens to damage by M. brunneum when entering soil indicates that orchard floor management of this pest may be possible.