Mating Strategies and Variable Mate Guarding Behavior of Gypsy Moth, Lymantria dispar japonica L., Males (Lepidoptera; Lymantriidae)

The gypsy moth, Lymantria dispar L, in Japan showed two patterns of copulation; duration type I and type II. Type I copulation was the more typically seen type and was sufficient to fertilize almost all of a female's eggs. Type II copulation continued until the female began pre-ovipositional behavior and occurred when other males were attracted to the copulating pair. Type II copulation, therefore, appears to be a mate guarding strategy by males. Males changed their strategies from mate searching to mate guarding in response to disturbances by other males.