BIONOMICS OF ADULT ANOPHELES-PSEUDOPUNCTIPENNIS (DIPTERA, CULICIDAE) IN THE TAPACHULA FOOTHILLS AREA OF SOUTHERN MEXICO

Field studies on the bionomics of adult Anopheles pseudopunctipennis T heobald were conducted to assess its relative importance as a primary vector of vivax malaria in southern Mexico. In four malaria endemic vi llages in a foothill region near Tapachula, Mexico, population densiti es of A. pseudopunctipennis increased during the dry seasons of 1990 a nd 1991. The pattern of nocturnal host-seeking activity indoors was un imodal with a late night peak at 0100 hours enhancing its vectorial si gnificance, because it occurred when most residents were asleep and fu lly exposed to the anophelines. Comparisons of trapping methods showed that a horse-baited trap was more effective than human landing catche s or UV light traps. Pit shelters, on the other hand, were more effect ive than indoor and natural shelter resting collections. Results of en zyme-linked immunosorbent assays performed on wild-caught A. pseudopun ctipennis specimens documented the presence of natural infections with the VK210 and new VK247 circumsporozoite polymorphs of P. vivax. Thes e findings verify the importance of A. pseudopunctipennis as a major v ector of vivax malaria at higher elevations and extend the geographica l range of the VK247 P. vivax polymorph in Mexico.