Temporal and spatial distribution of anopheline mosquitos in an Ethiopian village: implications for malaria control strategies.

The spatial and temporal distribution of Anopheles gambiae mosquitos in houses in the village of Sille in Ethiopia was monitored in 1990-91. Monthly mosquito densities in over 300 houses were obtained, and the data for each month were plotted on maps, which indicated clustering of mosquitos within the village. Spatial analysis using "kriging" techniques demonstrated clustering towards the edges of the village, the pattern of which changed with time. For example, the low density of mosquitos in one area in September increased as the nearby irrigation canals dried up during the following months. Since most entomological activity occurred at the periphery of the village, focal spraying of these areas could be a cost-effective procedure. If such clustering occurs in other villages, selective control of breeding sites and indoor spraying could provide a more efficient use of limited resources than traditional total coverage.