Mating behavior observation
Ten males and ten females were reared in each cage to investigate their mating behaviors. These adults were observed 24 h a day during 6–10 July 2015 to check the circadian rhythms of mating activity. Then adults were observed every 30 min from daybreak to noon to record the mating behaviors, including mating positions and copulatory processes. Photographs were taken with a Nikon D90 digital camera.