BIONOMICS OF LARVAL POPULATIONS OF ANOPHELES-PSEUDOPUNCTIPENNIS IN THE TAPACHULA FOOTHILLS AREA, SOUTHERN MEXICO

The population dynamics of Anopheles pseudopunctipennis larvae were st udied in a foothill region near Tapachula, Mexico. Systematic surveill ance of wet-season and dry-season habitats was conducted during 1990 a nd 1991. Sampling along transects of the Coatan River was employed to quantify habitat availability and population densities of larvae durin g the dry season. During the wet season, larvae were most abundant in temporary habitats, such as seepage springs, rain pools, and pools in stream and river margins. The temporary habitats disappeared during th e dry season, which occurred concurrent with incrasing densities of la rvae in dry-season habitats within transects along the Coatan River. T he great abundance of the dry-season riverine habitats, viz., small po ols with filamentous algae, resulted in peak densities of host-seeking adult populations in villages associated with the river. During both seasons, there were significant associations between the presence and abundance of larvae and habitats containing filamentous algae, and sec ondarily with selected aquatic and semiaquatic plants. There was a sig nificant correlation between mean numbers of larvae per habitat and me an numbers of breeding sites in the transects. Overall, An. pseudopunc tipennis larvae were very abundant during the dry season and relativel y uncommon during the wet season.