Aquatic Insect Fauna of Three River Systems in the Akyem Abuakwa Traditional area of The Eastern Region of Ghana

Abstract

Three river systems in the Akyem Abuakwa Traditional Area: Ayensu, Birim and Densu were sampled over a period of one year during the wet, dry and intermediate seasons for aquatic insect fauna. Fifteen sampling sites were chosen based on certain parameters such as accessibility as well as the inclusion of high and low impact sites (i.e. close to or far from a town or village) or near areas with high human activity. Four sampling methods were employed: sweeping, core sampling, sieving and washing of stones, wood fragments and submerged objects as well as aquatic plants and leaves. Fifty seven (57) species of aquatic insects belonging to 26 families of 7 orders were recorded. Hemiptera, Ephemeroptera and Odonata were the most diverse and abundant orders with Hemiptera being the most diverse order with 17 species from 8 families. The most abundant species was Rhagovelia obesa (Hemiptera: Veliidae). The highest number of insects was collected in December whiles July recorded the lowest numbers. River Densu recorded the highest number of insects whiles River Birim recorded the highest diversity of insects with 36 species. River Ayensu had both the lowest numbers and diversity of insects.