PI(s): Bergh, J Christopher (Project Leader)

Abstract:

Description:My current Hatch project extends from July 1, 2007 through June 30, 2012. Larvae of numerous species of clearwing moths, family Sesiidae, are damaging pests of many economically important horticultural crops. The dogwood borer (DWB), Synanthedon scitula Harris, is considered a relatively polyphagous pest of deciduous ornamental, fruit and nut trees in eastern North America. Although known historically as a pest of flowering dogwood, DWB has become particularly abundant in apple orchards and can be a serious impediment to the establishment, growth and survival of young apple trees planted on size-controlling rootstocks in high density orchards. By comparison, the host range of the grape root borer (GRB), Vitacea polistiformis (Harris), is restricted to wild and commercial grapevines in the eastern US. Larvae of GRB feed exclusively on the roots of grapevines, causing reductions in vine vigor and productivity, and potentially, vine mortality. Cultural management tactics for these pests are labor-intensive, only partially effective and can have adverse horticultural side-effects, while pesticide-based management options for them are very limited, compared with those available for controlling other lepidopteran pests. Trunk and soil drench applications of the organophosphate pesticide, chlorpyrifos (Lorsban), are considered most effective against DWB and GRB, respectively. However, a review of chlorpyrifos for re-registration is scheduled for 2009 and, given that the tolerances of organophosphate pesticides continues to diminish under the Environmental Protection Agency's 1996 Food Quality Protection Act, the long-term availability of this compound is quite uncertain. This scenario provides the incentive and rationale for further research on the behavioral and chemical ecology of these species, ultimately toward the development of novel and environmentally benign monitoring and management tactics that are based on behavioral manipulation. The overarching goal of this project is to explore the existence of and response to host plant derived semiochemicals by DWB and GRB. Specifically, I propose to investigate the use of volatile, host plant odors by mated female DWB in their location of oviposition sites and the use of behaviorally active compounds associated with grape roots in the orientation of larval GRB to feeding sites. An ancillary goal is the development of acoustic emissions detection technology to address questions about the biotic factors that influence the distribution of GRB infestations in commercial vineyards.