A study on the aquatic insects occurring at the school swimming pools : its application to environmental education.

为了将淡季在学校游泳池出现的水生昆虫应用于环境教育，我们收集了它们的生态信息，主要集中在以下几个方面：(i)在泳池内发现的蜻蜓幼虫和其他水生昆虫的种类组成；（ii）优势蜻蜓幼虫的生活史；（iii）这些物种在泳池内占优势的原因；以及（iv）以蜻蜓幼虫为食的摇尾虫的食物浮游植物的种类组成。在京都市和津都市2年的调查和实验结果表明：(1)京都市小学游泳池中共发现8种蜻蜓幼虫，其中以斑纹双翅蛾最为常见，而在津都市则以斑纹双翅蛾为主，斑纹双翅蛾未分布；(2)有限纹曲线虫幼虫在游泳池中普遍存在的原因是，其10月产卵，次年6月成虫羽化的生活史模式与游泳池非使用期相吻合，雌虫直接产卵入水；(3)京都市游泳池浮游植物中最常见的浮游植物是贝壳藻。

To apply the aquatic insects occurring at the school swimming pools during off-season to environmental education, we gained their ecological information focussing on a few subjects : (i) species composition of the dragonfly larvae and other aquatic insects found in the swimming pools, (ii) life histories of the dominant dragonfly larvae, (iii) the reason why those species are dominant at a swimming pool, and (iv) species composition of phytoplankton, the food of chironomids which are prey of dragonfly larvae.Surveys and experiments for 2 years in Kyoto City and Tsu City revealed that (1) eight species of dragonfly larvae were found at the swimming pools of the primary schools in Kyoto City, especially Sympetrum striolatum imitoides was most common, on the other hand, the larvae of Orthetrum albistylum speciosum were dominant in Tsu City where S.striolatum imitoides is not distributed ; (2) the reason why larvae of S.striolatum imitoides are found so commonly at swimming pools is that, their life history pattern of laying eggs in October with adult eclosion the next June coincides with the non-use period of the pools, and females lay eggs directly into the water ; (3) Cosmarium was the most common phytoplankton at the swimming pools in Kyoto City.