MORPHOMETRIC DISCRIMINATION OF THE SIBLING SPECIES DROSOPHILA-MELANOGASTER (MEIGEN) AND DROSOPHILA-SIMULANS (STURTEVANT) (DIPTERA, DROSOPHILIDAE)

The sibling species Drosophila melanogaster and D. simulans often co-o ccur. Males are easily distinguished using their genitalia while femal es of the two species are often deemed indistinguishable. A series of nine linear and two angular measurements were taken using the heads of both males and females of both species from the same locality. A simp le comparison of cheek width and eye height accurately assigned all fe males to species. Multivariate techniques using linear head measures a lone produced very good discrimination between both species and sexes. Drosophila simulans have significantly larger eyes and narrower eye m argins than D.melanogaster. Unknown females collected from this locali ty could be easily and reliably assigned to species.