Submitted to: Journal of Entomological Sciences
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/17/2003
Publication Date: 7/1/2004
Citation: Shapiro Ilan, D.I., Cottrell, T.E., Gardner, W.A. 2004. Trunk perimeter applications of beauveria bassiana to suppress adult curculio caryae (coleoptera: curculionidae). Journal of Entomological Sciences. 39:337-349. Interpretive Summary: The fungus Beauveria bassiana is an environmentally friendly natural pesticide. The fungus can control many economically important insect pests. We are evaluating the potential to use this fungus to control the pecan weevil, which is a major pest of pecans. The fungus caused up to 95% mortality in adult pecan weevils within the first week following application. The effects of the fungus were greater in plots that did not receive irrigation compared with plots that did. In all cases, the effects of the fungus did not last longer than one week. Therefore, future research must focus on prolonging the effects of the beneficial fungus.
Technical Abstract: The pecan weevil, Curculio caryae (Horn) is a key pest of pecans. Entomopathogenic fungi such as Beauveria bassiana (Balsamo) Vuillemin, have been shown to be pathogenic towards this pest. Our primary objective was to determine the potential of B. bassiana, applied to soil around pecan tree-trunks, to suppress emerging C. caryae adults, and (secondarily) to determine the potential of subsequent B. bassiana recycling. In 2000 and 2001, B. Bassiana was applied in a 2-m band around pecan tree trunks at two locations. In Byron, GA, results indicated greater fungus induced mortality in plots that received B. bassiana with irrigation than in plots that received B. bassiana with irrigation. In Griffin, the 2000 results indicated higher C. caryae mortality in B. bassiana treated plots than in non-treated plots, whereas 2001 results showed no difference. Future research should focus on extending the persistence of B. bassiana suppression. Estimates of conidia production yielded up to 4.2 x 10-9 per B. bassiana infected insect indicating some potential for recycling of the applied fungus.