ABSTRACT
Drosophila are small two-winged flies. The most studied species, D. melanogaster, has a head and body length of about 2.5 mm for males and 2 mm for females. The genus con tains at least 2,000 species (Spieth, 1968), and all are of behavioral and ecological interest for their courtship and mating systems, for their evolution, and for their adaptations to different environments. However, very few species have been studied in detail. The small percentage that have are those that adapt best to laboratory conditions. For this reason most of what we know about Drosophila behavior relates to their behavior in the laboratory. A recent devel opment in research has been to combine labo ratory and field studies (Crossley 1988a; Par tridge, Hoffman 5c Jones, 1987).
