Drosophila subobscura

Drosophila subobscura is a species of fruit fly in the family Drosophilidae. 
It was originally found around the Mediterranean, but it has spread to most of Europe and the Near East. It has been introduced into the west coasts of Canada, the United States, and Chile.
 This species is in the "Sophophora" subgenus. 
Study organism for evolutionary biology.
In 1933, A.H. Sturtevant captured a species of Drosophila in England. It was a member of "Drosophila subobscura".
"D. subobscura", with others in its species group, is a model organism for evolutionary-biological studies. Its genetics and ecology have been studied for over fifty years.
They have served as favourable models ever since Dobzhansky and his colleagues published their influential works in the 1930s and 40s. 
Their use as a regular laboratory fly was promoted by J.B.S. Haldane and John Maynard Smith at University College London over a period of about 30 years. There it was used for research into population genetics, and for teaching genetics. For many years this species was the European "rival" to the "D. pseudoobscura" favoured by the group in California led by Dobzhansky.