ABSTRACT

 The survey of aquatic insect of Aham stream in obowo Local Government Area of Imo State, Nigeria was carried out over a period of 3 months. Also, selected physico-chemical parameters were assessed. The stream was investigated in 3 different stations based on human activities and the plant community along the length of the stream. Insects were sampled using standard entomological methods, while water samples were analyzed using standard Winkler's titrimetric and APHA methods to determine the chemical properties. The mean value of the studied parameters, except for phosphate ion content, were within the permissible limit of World Health Organization (WHO) and Standard Organization of Nigeria (SON) for drinking water. The phosphate ion contents were 1.73 + 0.28 in station 1, 1.80 + 0.39 in station 2, 1.81% 0.42 in station 3. There were no significant differences at p<0.05 for the physico-chemical parameters assessed. A total of 14 families representing 9 orders of insects were recorded. At order level, Hemiptera recorded the highest frequency in total abundance (36.47%) followed by Odonata (32.94%), Ephemeroptera (14.12%), Coleoptera (1.06%), Diptera (3.54), Plecoptera (2.35%), Orthoptera (1.18%), Lepidoptera (1.18%), Neuroptera (1.18%). The family Conenagrionidae was the most abundant aquatic insect taxa followed by Gerridae. Based on the result and WHO and SON criteria, the stream could be said to be suitable for domestic, industrial and agricultural uses, however basic treatment can help to improve the quality of the stream.