都市近郊の農村域におけるクツワムシの生息実態

抄録

The calling songs of cicadas and orthopterans have had a symbolic influence on the Japanese people, and these species are important as they make people understand the value of ecosystem services. In this study, we focused on Mecopoda nipponensis, a well-known acoustic insect in Japan, and we aimed to clarify its distribution in rural areas near large cities. The study site was Ushiku and Tsukuba Cities in Ibaraki Prefecture, Japan. By using a method for counting the sound of M. nipponensis, we recorded its distribution a few times during the summer of 2012 in large (for 5 km around) and small (for 500m around) areas. In addition, we created vegetation maps by conducting field surveys or by obtaining them from existing government data. In the large-scale analysis, the relationship model between the distribution of M. nipponensis and vegetation type from vegetation maps was constructed by using a logistic regression model, and selected best combination of explanatory variables by AIC criterion. Analysis of the large-scale areas revealed that vegetation type such as city, cultivation, and wetland areas around the 600-700m buffer had a statistically negative influence on the M. nipponensis distribution. In the small-scale analysis of density of populations, tall grasslands, forests, and forest edges were found to be important habitats. This study shows that M. nipponensis is vulnerable to environmental changes and is therefore a good environmental indicator species.