Environmental Entomology (2008) 37, 162-171

David I. Shapiro-Ilan, Wayne A. Gardner, Ted E. Cottrell, Robert W. Behle and Bruce W. Wood (2008)
Comparison of application methods for suppressing the pecan weevil (Coleoptera: Curculionidae) with Beauveria bassiana under field conditions
Environmental Entomology 37 (1), 162-171
Abstract: The pecan weevil, Curculio caryae (Horn), is a key pest of pecans. The entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin is pathogenic to C. caryae. One approach to managing C. caryae may be application of B. bassiana directed toward adult weevils as they emerge from the soil to attack nuts in the tree canopy. Our objective was to compare different application methods for suppression of C. caryae adults. Treatments included direct application of B. bassiana (GHA strain) to soil under the tree canopy, soil application followed by cultivation, soil application in conjunction with a cover crop (Sudan grass), direct application to the tree trunk, and application to the trunk with an UV radiation-protecting adjuvant. The study was conducted in a pecan orchard in Byron, GA, in 2005 and 2006. Naturally emerging C. caryae adults, caught after crawling to the trunk, were transported to the laboratory to determine percentage mortality and signs of mycosis. When averaged over the 15-d sampling period, weevil mortality and signs of mycosis were greater in all treatments than in the nontreated control in 2005 and 2006; >75% average mortality was observed with the trunk application both years and in the trunk application with UV protection in 2005. Results indicated trunk applications can produce superior efficacy relative to ground application, particularly if the ground application is followed by cultivation. Efficacy in the cover crop treatment, however, did not differ from other application approaches. Future research should focus on elucidating the causes for treatment differences we observed and the extent to which B. bassiana-induced C. caryae mortality reduces crop damage.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): David I. Shapiro-Ilan, Ted E. Cottrell, Robert W. Behle

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
environment - cropping system/rotation
Research topic(s) for beneficials or antagonists:
application technology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Curculio caryae	Pecan/hickory (Carya)	U.S.A. (SE)
Beauveria bassiana (entomopathogen)	Curculio caryae	Pecan/hickory (Carya)	U.S.A. (SE)