Ecological Knowledge of an Endangered Species Libelloides ramburi (MʼLachlan, 1875) (Insecta, Neuroptera) in Kanagawa Prefecture, Japan, Part 2―Study on the Population Dynamics by the Marking Method―

Abstract

Libelloides ramburi is an endangered species whose distribution in Kanagawa Prefecture is currently limited to a corner of the northern part of the prefecture. In this study, I report the results of the ecological survey conducted in 2022. In 2022, I marked 367 adults of L. ramburi for individual identification, of which 37 individuals (10 %) were recaptured. The result was similar to that of the 2021’s survey. These suggest that adult members in the populations interchange rather frequently. The days to survive was as 15 (males) and 19 (females) days, respectively. The ratio of males was high in the early season, but it remarkably decreased towards the end of the survey. Thus, the marking methods are useful for the solution of population dynamics of this species.