Basic Research on the Odonata Larvae as a Teaching Material from the Swimming Pool of Elementary and Junior High Schools

Abstract

The outdoor swimming pools of elementary and junior high schools in Tsu City, Mie Prefecture, were surveyed to clarify the community structure of odonate larvae. During 3 years, in 34 pools, we found a total of 13 species of odonate larvae, 2 of them were Zygoptera and 11 were Anisoptera. Crocothemis servilia mariannae, Orthetrum albistylum speciosum and Sympetrum infuscatum were common species in the pools examined in late May. The odonate community at the pools located in the hills showed a higher diversity index than that at the pools located in the plains. The larval density was approximately constant irrespecitive of the environment of the pools, 1 individual larva per meter of the bottom of pool along its longer side (25m). In early June when the water was drained for pool-cleaning, the odonate and the other aquatic insect communities were catastrophically destroyed. Larvae of Pantala flavescens were dominant at all pools in autumn. Very few larvae were collecled in the winter. In this study we discussed the odonate larvae as a teaching material for biology and the environment.