ESTIMATION OF GENETIC AFFINITIES BETWEEN SYMPATRIC POPULATIONS OF RHIPICEPHALUS-PUSILLUS TICKS (ACARI, IXODIDAE) BY ANALYSIS OF CUTICULAR HYDROCARBONS

Genetic distances and phylogenetic clustering are calculated for sympa tric populations of Rhripicephalus pusillus (Gil Collado) 1939 ticks, using cuticular hydrocarbon analysis and several statistical tools (st epwise discriminant analysis, Nei's genetic distance using different s ets of compounds, and Cavalli-Sforza's Brownian motion model). Discrim inant analysis on genic frequencies permits the detection of the most ancient geographic relationships between the populations, while the ge netic distance method determines current evolutive affinities. However , methods based on quantitative estimation provide a poor resolution. Genetic distances are very high in the populations studied, suggesting a strong reproductive isolation of the specimens involved.