EFFECT OF PHYSICO-CHEMICAL CHARACTERISTICS OF WATER OF RIVER OGUN ON THE DISTRIBUTION AND ABUNDANCE OF AQUATIC INSECTS

Abstract

This study was carried out to determine the abundance, composition, distribution of aquatic insects and physico – chemical factors of Ogun River. The aquatic insects were collected using sweep and pond net (0.5mm) from two study sites during February and middle April, 2012. The water samples and insects were collected once in a week. Insects were sampled using standard entomological methods, while water samples was analysed using standard Winkler’s titrimetric and APHA methods to determine the chemical properties. Water analyses were conducted in the laboratory of Ogun State Water Corporation, Abeokuta, Ogun State. While insects identifications were done in the laboratory in the Entomology Laboratory of the College of Natural Sciences, Federal University of Agriculture, Abeokuta, Nigeria. Results show that five orders and thirteen families were found with the highest number of aquatic insects from the order Odonata. The most abundant family were Coenagriidae and Libellulidae respectively. Physico – chemical values, water temperature, pH, Dissolved Oxygen ( DO), Conductivity and Nutrient were measured. Only conductivity had the greater value among the water quality parameters.