GENETIC-DIFFERENCES AMONG ANOPHELES VESTITIPENNIS SUBPOPULATIONS COLLECTED USING DIFFERENT METHODS IN CHIAPAS STATE, SOUTHERN MEXICO

Biting activity and population genetic studies of the malaria vector A nopheles vestitipennis were conducted in southern Mexico. Three subpop ulations were collected from 2 villages; 2 subpopulations were from th e same village, one on human bait and one with an animal-baited trap; the third was collected from a cattle corral in the 2nd village (280 k m away SSE). The anthropophilic subpopulation had steady activity with 61% of bites occurring before midnight, significantly different from those of the 2 zoophilic subpopulations, which had 78-82% of bites bef ore midnight and 2 biting peaks, one at 1900-2100 h and the other at 0 400-0500 h. Isozyme analysis (13 enzymes) of these subpopulations indi cated that differences between the 2 sympatric subpopulations (D = 0.0 7), collected using 2 different methods, were greater than that betwee n the 2 allopatric ones (D = 0.03). These studies suggest the existenc e of 2 genetically different subpopulations of An. vestitipennis with specific host preferences.