PATTERNS OF CUTICULAR HYDROCARBON VARIATION AND GENETIC SIMILARITY BETWEEN NATURAL-POPULATIONS OF AMBLYOMMA-CAJENNENSE (ACARI, IXODIDAE)

Gas chromatography has been used to analyze the variation in cuticular hydrocarbon patterns between several populations of Amblyomma cajenne nse. 88 compounds were detected and these could be divided into 17 gro ups of hydrocarbons. Heterozygosis in the populations ranges from 0% t o 25.84%. Isomers for pentacosane, heptacosane and nonatriacontane are the most variable, with 13, 10 and 11 variants, respectively. Nei's g enetic identity and genetic distance show that populations may be cons idered as regional variants of only one species: the results do not in dicate the presence of sibling species. However, a relatively high gen etic distance has been observed between several Cuban and continental populations, suggesting a long reproductive isolation. Gas chromatogra phy of cuticular hydrocarbons is a good alternative to isozyme analysi s for population studies, when collecting conditions do not allow the use of live ticks and only alcohol-preserved collections are available . The high number of compounds available for genetic studies will prov ide excellent markers for evaluating the extent of gene flow and migra tion of tick species.