|Holmes, William - MISS. STATE UNIV CHEM LAB|
Submitted to: Association Official Analytical Chemists Annual Intrl Meeting & Exposition
Publication Type: Abstract Only
Publication Acceptance Date: April 26, 2005
Publication Date: April 27, 2005
Citation: Brown, A.E., Holmes, W.E., Riddick, E.W. 2005. The use of gc/ms to identify potential aggregation pheromones in the multicolored asian lady beetle. Association Official Analytical Chemists Annual Intrl Meeting & Exposition. Meeting Abstract. Interpretive Summary: No summary required.
Technical Abstract: The multicolored Asian lady beetle, Harmonia axyridis, was released over twenty years ago as a biological control agent to manage pecan aphids in Georgia, USA. At present, H. axyridis is well-established throughout the continental United States and Canada. Although this insect has a positive impact, adults become a nuisance to homeowners when they invade houses in the fall season, in search of overwintering shelter. This beneficial predator can aggregate by the thousands in attics and wall voids. The best approach to managing this useful but problematic insect could involve a “push-pull” strategy. The idea is to use environmentally-friendly repellents to push beetles away from structures, and attractants/pheromones to pull beetles into specified traps. In order to identify attractants and/ or pheromones involved in aggregation we have utilized standard and novel methods to detect several volatile and semi-volatile organic chemicals released from H. axyridis males and females. The volatiles emitted from live beetles have been analyzed by solid phase microextraction (SPME) and whole air sampling coupled with gas chromatography and mass spectroscopy (GC/MS) in an effort to identify chemicals involved in aggregation. A carboxen/polydimethylsiloxane SPME fiber was placed within an environmentally-controlled chamber containing live beetles allowing the volatile organics to adsorb onto the fiber, whereas, in the whole air sampling, a volume of air was removed and trapped on a Tenex-G-Trap. The temperature can be systematically lowered in the environmental chamber to simulate the drop in temperature which triggers aggregation. A comparison of both sampling techniques will be described utilizing the inherent sensitivity of the ion trap mass spectrometer for detection capability.