Factors Affecting a Fauna of Aquatic Insects in Swimming Pools of Schools in the Southern Part of Nagasaki, Japan

Abstract

Aquatic insects colonize the swimming pools of schools during the off-season. The present study aimed to investigate 30 swimming pools in southern Nagasaki Prefecture in spring（middle April to middle May）and autumn（late October to early November）2014. We found 11 families of aquatic insects including 9 Heteroptera, and 9 Coleoptera. Appasus japonicus（Heteroptera: Belostomatidae）, Hesperocorixa kolthoffi（Heteroptera: Corixidae）, and Cybister tripunctatus lateralis（Coleoptera: Dytiscidae）designated as “Red Data List” species（red list species）were collected from the school pools. The community composition of aquatic insects was divided into spring and autumn, and its variance was related to the water temperature and organic matter. The major environmental factor related to the number of red list species was considered to be location near the potential natural habitat of the species. The organic matter falling into the pools affected the existence of Orthetrum species nymphs（Orthoptera: Libellulidae）. Odonata nymphs, Notonecta triguttata（Heteroptera: Notonectidae）, Anisops ogasawaraensis（Heteroptera: Notonectidae）, Aquarius paludum paludum（Heteroptera: Gerridae）, and Eretes griseus（Coleoptera: Dytiscidae）were found from most of the pools studied, indicating that these species may be used as teaching materials for science in most schools irrespective of their location.