Mechanisms controlling species composition in natural populations of the seaweed fly Coelopa

Abstract

Summary Egglishaw (1960) suggested that the species composition of natural colonies of the kelp-fly Coelopa showed regular seasonal fluctuations. This has been found not to be universally true. The species composition of several colonies has been investigated and an attempt made to explain the observations in terms of selective effects of three observed differences in the biology of the two species of Coelopa found in Great Britain.