Arboreal Ants at Isolated Small Stands in Fujisawa City, Kanagawa Prefecture

Abstract

The arboreal ant fauna was investigated at isolated small stands in Fujisawa City, Kanagawa Prefecture, from June to November in 2013 and 2014. Ants were directly collected mainly from the trunks of living Quercus acutissima and Chamaecyparis obtusa in the daytime. In total, 15 species belonging to nine genera in four subfamilies were obtained from the tree trunks. Among these ant species, eight species （Camponotus quadrinotatus，C. nawai, C. itoi, C. keihitoi, Crematogaster matumurai，C. teranishii，Monomorium intrudens，and Dolichoderus sibiricus） are regarded to be truly arboreal. During the survey, 1786 ant individuals were collected from Q.acutissima and 563 from C. obtusa. Lasius japonica and Pristomyrmex pungens nearly always dominated on Q. acutissima and C. obtusa, respectively. The number of ant species and of individual ants collected from Q. acutissima was larger than that from C. obtusa. The number of ant species and of individual ants was positively correlated with air temperature and increased in the summer. In comparisons of the occurrence of ants among Q. acutissima, Q. serrata, C. obtusa，Cryptomeria japonica, Cornus controversa, and Prumus × yedoensis, the ants used Q. acutissima significantly more than C. obtusa. In addition, comparisons of the number of individuals of seven ant species among the six tree species mentioned above showed that a larger number of ants were found on Q.