|Shapiro Ilan, David|
|Mizzell Iii, Russell|
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2009
Publication Date: 5/5/2010
Citation: Shapiro Ilan, D.I., Cottrell, T.E., Mizzell III, R.F., Horton, D.L., Behle, R.W., Dunlap, C.A. 2010. Efficacy of Steinernema carpocapsae for control of the lesser peachtree borer, Synanthedon pictipes: Improved above ground suppression with a novel gel application. Biological Control. 54:23-28. Interpretive Summary: The lesser peachtree borer is a major pest of stone fruits. Alternative methods of controlling this pest are needed. One option may be the use of entomopathogenic nematodes, which are naturally occurring small round worms that are used as environmentally friendly bio-insecticides. A major hurdle in using these beneficial nematodes for lesser peachtree borer control is that the pest attacks the tree aboveground (on the trunk and limbs) where the nematodes are subjected to damaging environmental conditions. In this study, we compared a number of different formulations to improve the efficacy of aboveground nematode applications. We discovered that a sprayable gel (called Barricade®) combined with nematodes was the best formulation and caused substantial suppression of lesser peachtree borer. Therefore, we conclude that beneficial nematode treatments followed by application of a sprayable can enhance control of lesser peachtree borer and possibly other aboveground pests as well.
Technical Abstract: The lesser peachtree borer, Synanthedon pictipes is a major pest of stone fruits (Prunus spp) in eastern North America. Virulence of the entomopathogenic nematode, Steinernema carpocapsae (Weiser), to S. pictipes has been demonstrated in the laboratory. However, achieving field efficacy has been difficult because S. pictipes attacks the tree aboveground where nematodes are subjected to damaging environmental conditions. We investigated the potential of various formulations to improve the efficacy of aboveground applications. An anti-desiccant adjuvant, Shatter-Proof, was tested in field trials in 2008 and 2009. S. carpocapsae was applied alone or with Shatter-Proof to peach limbs pre-infested with S. pictipes larvae. Furthermore, the experiments included the following treatments: S. carpocapsae followed by a post-application covering of latex paint, moistened diaper, or a gel spray (Barricade®). Controls of water-only, or water plus Shatter-Proof, Barricade®, or paint (without nematodes) were also included. The nematodes-only treatment failed to reduce S. pictipes survival relative to the water-only control in either year. In both years, nematodes plus Barricade® was the only treatment that reduced S. pictipes relative to the controls and the nematodes-only treatment. We conclude that nematode treatments followed by application of a sprayable gel such as Barricade® can enhance control of S. pictipes and possibly other aboveground pests as well.