Location: Crop Bioprotection Research
Title: Quantitation of Electrophysiological Stimuli: Dose Response Study of Pheromone and Host Odor Attractants of Diorhabda Elongata Authors
Submitted to: International Society of Chemical Ecology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 11, 2006
Publication Date: N/A
Technical Abstract: The leaf beetle Diorhabda elongata Brulle (Coleoptera: Chrysomelidae) has been introduced into the U.S. as a biocontrol agent for saltcedar and has become well established in several western states. Gas chromatographic-electroantennographic detector (GC-EAD) analysis of volatiles collected from adult D. elongata feeding on saltcedar showed at least 15 compounds that were sensed by the antennae of male and female D. elongata. Blends of just a few of these EAD-active compounds are strong attractants to D. elongata in the field. The GC-EAD activity was related to the amounts of collected host odor material, which can vary greatly and depended on several factors such as the feeding activity of the adults, making predictions on possible behavioral significant compounds difficult. The GC-EAD active compounds, ranging from green leaf volatiles to sesquiterpenes differ in volatility. In order to compare antennal responses to the different EAD-active compounds, a simple quantitation technique of electrophysiological stimuli was developed that served as the basis of a dose-response study. Knowing the exact amount of stimuli presented to the antennal preparation allows for direct comparisons of antennal sensitivities to compounds with different volatilities. The quantitation showed that equal dosages of stimuli compound were being released at very different rates from our stimuli cartridges. Even the structurally very similar six-carbon green leaf compounds showed very different release profiles.