A natural population of Drosophila (Diptera: Drosophilidae) in Colombia

The natural population of a site in Fusagasuga, Colombia, was sampled weekly from March 1964 to December 1965, and weights of the collected adult Drosophila were determined. D. melanogaster Meigen, D. immigrans Sturtevant, D. cardini Sturtevant, and D. capricorni Dobzhansky & Paven were the most abundant species. The total number collected of D. immigrans, D. bandcirantorum Dobzhansky& Pavan, the D, tripunctata Loew group, and 77. griscolineata Duda was higher after rainy months than after dry months. This correlation did not hold for D. mclanogaster or D. cardini . The average weight of female D. melanogaster and D. immigrans collected during rainy months was higher than that of females collected during dry months. However, the reverse was true for D. cardini . A greater variety of species of Drosophila was taken at Fusagasuga than in a previous study at a higher altitude in Colombia.