The Anopheles maculipennis complex (Diptera: Culicidae): comparison of the cuticular hydrocarbon profiles determined in adults of five Palaearctic species

Abstract

A comparison was made between the cuticular hydrocarbons of five Palaearctic species of the Anopheles maculipennis Meigen complex; A. maculipennis sensu stricto, A. melanoon Hackett, A. messeae Falleroni, A. labranchiae Falleroni and A. atroparvus Van Thiel. Females of these species had their cuticular lipid removed and the hydrocarbons separated and quantified by gas chromatography. Discriminant analysis determined the degree of difference between the species. Wild caught adults of the complex had an average correct classification rate of 77.9%. A. atroparvus and A. labranchiae are homosequential and have no uniquely diagnostic isoenzymes, but expressed distinct hydrocarbon profiles enabling them to be separated in more than 86% of cases. Similarly, A. maculipennis sensu stricto and A. melanoon differ only by minor karyotype alterations, yet their hydrocarbon profiles could be separated with 83% correct classification. A dendrogram was drawn up, based on the hydrocarbons, using the Mahalanobis distances between species. A. maculipennis sensu stricto and A. melanoon were the two closest groups; A. messeae was next to join the cluster, followed by A. labranchiae and then A. atroparvus. These last two species were also very close to each other, but quite distant from A. maculipennis sensu stricto and A. melanoon. The species' relationships based on hydrocarbons thus reflect the tentative chromosomal phylogeny of the complex. In nature, hydrocarbon differences between species may be a device enabling the recognition of suitable mates. Studies showing that hydrocarbon dissimilarity is elevated between sympatric populations are also discussed in support of this theory.