Monday, December 10, 2007 - 9:29 AM

Impacts of pathogen-induced plant volatiles on the behavior of insect vectors

Lori R. Shapiro,, Pennsylvania State University, Department of Entomology, 501 ASI Building, University Park, PA, Andrew G. Stephenson, The Pennsylvania State University, Department of Biology, 208 Mueller Lab, University Park, PA, Mark C. Mescher,, Pennsylvania State University, Entomology, 538 Ag Sciences & Industries Bldg, University Park, PA, and Consuelo M. De Moraes,, The Pennsylvania State University, Department of Entomology, 542 ASI Building, University Park, PA.

Plant volatiles are important cues for foraging insects that can provide detailed information about the status and identity of the emitting plants. The key role of volatile cues in mediating interactions among plants, insect herbivores, and herbivore natural enemies is well established, but only recently have investigators begun to examine how these interactions are influenced by pathogen-induced changes in plant volatile profiles, which may have significant implications for disease transmission. We examined volatile induction in the wild gourd Cucurbita pepo ssp. texana, the native progenitor of the cultivated squashes, in response to infections by Erwinia tracheiphila, the causal agent of bacterial wilt disease, and zucchini yellow mosaic virus (ZYMV) and documented distinct volatile signatures for each pathogen. We are currently exploring the effects of these pathogen-induced volatile profiles on the behavior of the cucumber beetles Diabrotica undecimpunctata howardi and Acalymma vittatum, the only vectors of Erwinia tracheiphila, and on several generalist aphid species that vector ZYMV in a non-persistent manner. Implications for disease management in agriculture will be discussed.

Species 1: Coleoptera Chrysomelidae Diabrotica undecimpunctata howardi (spotted cucumber beetle)
Species 2: Coleoptera Chrysomelidae Acalymma vittatum (striped cucumber beetle)
Species 3: Cucurbitales Cucurbitaceae cucurbita pepo (wild gourd)