Cuticular hydrocarbons of four populations ofCoptotermes formosanus Shiraki in the united states : Similarities and origins of introductions

Abstract

The degree of similarity among cuticular hydrocarbon profiles of four populations ofCoptotermes formosanus Shiraki in the United States is reported. Sixteen individual or isomeric mixtures of hydrocarbons were identified by gas chromatography-mass spectrometry. Hydrocarbon components consist ofn-alkanes, 2-methylalkanes, 3-methylalkanes, internally branched monomethylalkanes on carbons 9-15, and dimethylalkanes. The predominant hydrocarbons have 27 carbons in the parent chain. Methyl-branched hydrocarbons are more abundant thann-alkanes. No qualitative differences were apparent in the hydrocarbon components of workers or soldiers from any of the four populations. Quantitative differences in the hydrocarbon components separate castes and populations into different concentration profiles. Stepwise discriminant analysis and canonical discriminant analysis were used to choose and display seven hydrocarbon components for workers and three for soldiers that best reveal the differences among populations. Within-population variation is low compared to the differences among populations. These results suggest thatC. formosanus from Hallandale, Florida; New Orleans, Louisiana; and Lake Charles, Louisiana, are not related to those from Honolulu, Hawaii, and probably originated from other geographical locations.