Basic research to clarify the cause of the decline of a tiger beetle Cylindera bonina ―NPO Association for Bonin Oceanic Island Studies Society―

Abstract

The endangered tiger beetle Cylindera bonina, found exclusively on Ani Jima Island in the Ogasawara Islands, continues to decline in the wild despite conservation efforts of Ministry of Environment, Government of Japan since 2010. Our study employed long-term video monitoring (totaling 3,818 hours) to record behavior of the larvae. Using equipment capable of recording up to 255 hours per session, it was found that the larvae primarily prey on springtails and ants, which was the first record of their feeding habits. Additionally, we observed previously unknown behavioral responses to rainfall, including patterns of burrow construction and relocation. These findings provide better understanding of the reasons for the species' population decline, and offer valuable guidance for future conservation strategies to prevent extinction.