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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #142386
Title: THE EFFECT OF MOLECULE STRUCTURE ON THE OLFACTORY DISCRIMINATION BY THE PARASITOID MICROPLITIS CROCEIPES

Author
item MEINERS, TORSTEN - FREIE UNIV. BERLIN
item WACKERS, FELIX - NIOO CTO/NETHERLANDS
item LEWIS, WALLACE

Submitted to: Chemical Senses
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/29/2002
Publication Date: 11/1/2002
Citation: Meiners, T., Wackers, F., Lewis, W.J. 2002. The effect of molecule structure on the olfactory discrimination by the parasitoid Microplitis croceipes. Chemical Senses. 27:811-816.

Interpretive Summary: A better understanding and use of natural enemies of agricultural pests is important to developing effective alternatives to the economic costs and environmental hazards of conventional pesticides. ARS scientists at Tifton, GA, together with their cooperators, are studying how the parasitic wasp, Microplitis croceipes, a natural enemy of the bollworm/corn earworm, detects and tracks chemical cues to optimize their host/pest-finding effeciency. They demonstrated that this wasp has a keen ability to distinguish between structurally related alcohols and aldehydes, chemicals typically associated with host presence and plant-feeding activities. The wasp could distinguish, learn and subsequently recognize different isomers of six-carbon alcohols on the basis of the position of the alcoholic group as well as between 1-hexanol and 1-hexanal. This knowledge of the keen chemical sensing abilities of parasitic wasps is an important step in developing improved strategies for biologically-based pest management of agricultural crops.

Technical Abstract: Flight chamber experiments were conducted to examine the capacity of the larval parasitoid Microplitis croceipes (Hymenoptera: Braconidae) to learn to distinguish between structurally related aliphatic alcohols differing in the carbon chain-length and the position of the functional group and between an alcohol and the respective aldehyde. The parasitoids ability to discriminate between the components depended on the chain-length of the trained alcohol. Discrimination improved with increasing difference in carbon chain-length, e.g. the parasitoids made clear differences between 1-hexanol and 1-octanol. M. croceipes could also distinguish different isomers of six-carbon alcohols on the basis of the position of the alcoholic group as well as between 1-hexanol and 1-hexanal. The learning abilities of M. croceipes correspond to the specificity of antennal odour receptors towards aliphatic alcohols and aldehydes in previous electrophysiological studies of M. croceipes and other insects. Differences in perception or processing of single compounds might reflect differences of their ecological relevance.