Environmental Entomology (2013) 42, 253-261

David I. Shapiro-Ilan, Wayne A. Gardner, Lenny Wells, Ted E. Cottrell, Robert W. Behle and Bruce W. Wood (2013)
Effects of entomopathogenic fungus species, and impact of fertilizers, on biological control of pecan weevil (Coleoptera: Curculionidae)
Environmental Entomology 42 (2), 253-261
Abstract: The pecan weevil, Curculio caryae (Horn), is a key pest of pecan, Carya illinoinensis (Wangenh.) K. Koch. Prior research indicated the potential for use of Hypocreales fungi to suppress C. caryae. We compared the efficacy of two fungal spp., Beauveria bassiana (GHA strain) and Metarhizium brunneum (F52), in their ability to cause C. caryae mortality. The fungus, B. bassiana, was applied to trunks of pecan trees (a method previously shown to be effective in C. caryae suppression) and efficacy was compared with M. brunneum applied to the ground or to the trunk with or without SoyScreen Oil as an ultraviolet protecting agent. Results indicated B. bassiana to be superior to M. brunneum regardless of application method; consequently, the potential for applying B. bassiana to control C. caryae was explored further. Specifically, the impact of different fertilizer regimes (as used by pecan growers) on the persistence of B. bassiana (GHA) in soil was determined. B. bassiana was applied to soil in a pecan orchard after one of several fertilizer treatments-i.e., ammonium nitrate, crimson clover, poultry litter, clover plus poultry litter, and a no-fertilizer control. B. bassiana persistence up to 49 d in 2009 and 2010 was assessed by plating soil onto selective media and determining the number of colony forming units, and by baiting soil with a susceptible host, Galleria mellonella (L.). Fertilizer treatments did not impact B. bassiana persistence. We conclude that standard fertilizers for nitrogen management, when applied according to recommended practices, are unlikely to negatively impact survival of B. bassiana in pecan orchards when the fungus is applied for C. caryae suppression during weevil emergence. Additional research on interactions between entomopathogenic fungi and fertilizer amendments (or other tree nutrition or soil management practices) is merited.
(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
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Curculio caryae	Pecan/hickory (Carya)
Beauveria bassiana (entomopathogen)	Curculio caryae	Pecan/hickory (Carya)
Metarhizium brunneum (entomopathogen)	Curculio caryae	Pecan/hickory (Carya)