Males of a number of species produce more than one type of sperm, some types contain and some lack DNA. Males of Drosophila obscura produce sperm of various discrete lengths, a phenomenon known as polymegaly. While all types contain DNA, the potential biological benefit of producing different lengths is unknown. In fact, the evolutionary significance of this polymorphism is not understood in any species. The present study tests the biological and evolutionary significance of polymegaly in some members of the Drosophila obscura group. In addition to a better understanding of basic reproductive biology and evolutionary theory, this research may assist in the development of biological control programs. One current methodology for "natural" insect pest control is to release many sterile males in the hopes that females will mate with these males rather than fertile males currently in the population. Since a number of insect species exhibit sperm polymorphism, this research may provide information useful in pest management programs.
