MATING-BEHAVIOR IN SEAWEED FLIES (COELOPA-FRIGIDA)

Video recordings were used to obtain a detailed description of the mating behavior of seaweed flies. The roles of wings, antennae, and legs were inferred from ablation and masking experiments. There is no apparent interaction between flies over a distance of more than 1-2 cm. After mounting the prothoracic legs of the male are located in the region of the female's antennae and interactions between these structures appear to facilitate successful mating. There follows either a female rejection response or a voluntary dismount by the male, or mating proceeds to insemination. When triplets of one female and two males were observed, larger males often displaced small males and were themselves less frequently displaced. The observed opportunities for female choice, male choice, and male-male competition are discussed in the light of previous reports of differential male mating success and of assortative mating with respect to size and genotypes. © 1990 Plenum Publishing Corporation.