Submitted to: Comparative Biochemistry and Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/3/2001
Publication Date: 9/1/2001
Interpretive Summary: The surface cuticular lipids of Hymenoptera, i.e., ants, bees, termites and wasps, which are mainly hydrocarbons, play important roles in colony, caste, and sibling recognition, and are useful as taxonomic characters to distinguish similar species. We have shown that there are minor, but clear differences in the specific hydrocarbon components (in the saturated methyl-branched alkanes) between ants held in the laboratory and those in the field of the species Pogonomyrmex barbatus. Field ants have less hydrocarbon and lack 2-methylalkanes which are present in the hydrocarbons of laboratory-held ants. Instead, the field ants had trace amounts of 4- methyalkanes. Both laboratory and field ants had similar amounts of wax. The delineation and identification of these previously unknown differences provide the fundamental information for behaviorists to determine the role of specific compounds on insect behavior.
Technical Abstract: Ants held in the laboratory and field ants of the species Pogonomyrmex barbatus have quantitative differences in their cuticular hydrocarbons and a qualitative difference in their methyl-branched hydrocarbons. Laboratory-held workers showed twice the hydrocarbon content as field ants. This difference was mainly due to higher amounts of straight-chain alkanes and methyl-branched alkanes in laboratory ants, whereas the proportion of the alkenes remained the same for both groups. In addition to the absence of some hydrocarbons in the field colonies, one of the methyl-branched hydrocarbons differed in amount and branching pattern between the two groups of ants. Whereas notable peaks of 2-methylalkanes were identified in ants kept in the laboratory, these compounds could not be identified in ants living in their natural habitat. However, a trace amount of 4-methyltriacontane was found in lieu of the 2-methyltriacontane counterpart in field ants. Possible explanations for both qualitative and quantitative differences are discussed.