Variation in Hunting and Mating Behavior in Two Populations of the Japanese Hangingfly Bittacus mastrillii (Mecoptera: Bittacidae)

The hunting and mating behavior of Bittacus mastrillii Navas was studied at 830 and 1,600 m above sea level. In the former population, both males and females congregated after sunset at thistle flowers in full bloom to prey on insects; they also mated continuously at the same site. At the higher site, males visited the forest edge to prey on arthropods in the afternoon. Males used wide-area searching with flight (vegetation sweeping) to hunt prey. Prey-hunting males lured females with pheromone emission. Simultaneous feeding by both sexes during the prolonged copulation was observed at low temperatures. B. mastrillii hunted at air temperatures of ≈6-16°C at both sites. Differences in the daily active periods between the 2 populations are correlated with differences in elevations. The difference in the daily active period leads to a difference in resource availability. B. mastrillii is able to switch its hunting behavior according to the spatiotemporal distribution and abundance of prey arthropods. Males are able to switch their mating behavior in response to changes in their hunting behavior.