Foraging activity of sympetrum infuscatum (Selys) adults living in Satoyama forest gaps (Odonata: Libellulidae)

Abstract

Adult Sympetrum infuscatum (Selys) live in the forest gaps throughout their life except when visiting rice paddy fields for oviposition. They prey on small flying insects in the forest gaps, using sit-and-wait tactics. They perch on the tips of branches or grass all day and take off when a small flying insect comes into sight. In the present study, the foraging behavior of S. infuscatum in the forest gaps was observed. The perching height was high in the morning and evening and low around noon. The diurnal change in the perching height corresponded to the abundance of flying small insects. The mean daily frequency of foraging flights was 251 for females and 182 for males, and the mean actual number of insects captured was 109 and 89, respectively. A total of 2,935,300 small flying insects were preyed on by S. infuscatum adults during one day in the Satomaya forest gaps.