2012 Annual Report
1a.Objectives (from AD-416):
1. To collect the ex situ and/or in situ volatile emission of select native and non-native oak trees (Quercus spp.).
2. To analyze collected volatile organic compounds (VOCs) via GC-MS and identify possible chemotaxonomy trends and/or chemotype identifiers of selected trees to various insect pests.
3. To identify VOCs with kairomonal behavior to select insect pests.
1b.Approach (from AD-416):
To accomplish the stated objectives the following approach will be utilized by the graduate student under the mentorship of a UC Davis professor and secondary supervision of an ARS Albany location scientist:
1. Perform ex situ VOC analysis on a large portion of selected oak tree (Quercus spp.) leaves to determine general VOC emission trends.
2. Utilize the in situ small-scale collection method (collection bag, SPME) of the USDA-ARS PMR unit to acquire VOCs from select trees identified from ex situ analysis.
3. Separate and identify collected VOCs via GC-MS analyses.
4. Develop a chemotaxonomic tree based upon trends of identified VOCs and herbivore damage.
5. Utilize electrophysiological and/or behavioral bioassays to determine kairomonal activity. Documents NFCA with UC Davis.
This report serves to document research conducted under the NFCA (#58-5325-0-0132N) between ARS and the University of California, Davis Department of Entomology (UCD). Additional details of research can be found in the report for the parent project Biological Control of Insects and Microorganisms to Prevent Mycotoxin Contamination (Project Number 5325-42000-036-00).
The project was extended past the first year to allow the graduate student (now graduated with a Ph.D.) to write up the results. A manuscript entitled “Headspace volatiles from 52 oak species advertise induction, species identity, and evolution, but not defense” was recently submitted (7/17/2012) to the Journal of Chemical Ecology. The UCD scientist involved with this project is working on a second paper detailing the results of this project.
The goals of this project, collecting and identifying volatiles as potential kairmones for oak insect pests, are related to objective 3 of the in-house project and are a direct application of methods developed in this laboratory.