Male Mating Success in Diptera: Advantages of Small Size

Small size may be advantageous to males that mate on the wing. This hypothesis is supported by the results of a comparison of size in males that mate and those that do not. Six species of Diptera (four chironomids, one sepsid and one scatophagid) are examined and in all six, smaller males are more successful at acquiring mates than larger males. Aerobatic ability may be conferred by small size and, if this is so, it could explain why smaller males achieve greater success. The conclusion that small size carries a selective advantage contrasts with the conventional view that large size is a universal determinant of mating success among males.