Diurnal locomotion activity of adult rice bug, Leptocorisa chinensis (Hemiptera: Alydidae), at different ages, measured by actograph and video camera

To elucidate the relationship between locomotion activity and reproductive status versus age after eclosion of the rice bug, Leptocorisa chinensis , locomotion activity and mating behavior were investigated by use of an actograph and video recording system. Locomotion activity of males and females 3, 7, 14, and 21 days after eclosion was recorded. High locomotion activity was observed in the scotophase. In both sexes, the activity pattern changed with age; that is, settling mode was observed in younger (3 and 7 days old) individuals and locomotion mode in older (14 and 21 days old) individuals. Locomotion activity in the scotophase in settling-mode individuals was lower than in locomotion-mode individuals, and they often stayed on rice panicles all day. On the other hand, the activity of locomotion-mode individuals was high throughout the scotophase. Most locomotion-mode males had mature gonads. Courtship and mating behavior occurred in the scotophase. The results indicate that L. chinensis adults spend a lot of time on food plants and their gonads develop during the young, teneral period. They subsequently change to the locomotive mode and move around, probably for reproductive activity.