Odonata fauna of contrasting semi-aquatic and terrestrial ecosystems in Awka, Nigeria

Abstract

The sweep net was used to study the Odonata fauna of the Permanent Site of Nnamdi Azikiwe University, Awka for a twelve-month period. The Odonata species collected from the marshy plot included Orthetrum chrysostigma, Ceriagrion glabrum, Platycnemis subaequistyla Fraser and Nesciothemis nigeriensis while Hemistigma coronata and Palpopleura lucia were obtained from thefallow plot. Only two species - Palpopleura lucia and Hemistigma albipuncta were collected from the cultivated plot. A statistical analysis of the collections of these insect species using Analysis oVariance (ANOVA) failed to show any significant differences at F-ratio of 0.458 and p-value of 0.6339, even though higher numbers of species were obtained at the wetland. Similarly the sweepnet catches failed to show any significant differenceusing the Fisher's Least Significance Difference(F-LSD) test at 5% probability level. The higher catches of the odonates at the marshy plot was traced to the nature of the habitat. The role of these sub aquatic species as indicators of ecosystem quality was hghlighted.

Keywords: Odonata fauna, Semi-aquatic ecosystem, Awka,