Bettle fauna of agro and forest ecosystems in a tropical rainforest habitat, Nigeria

Abstract

An investigation was carried out to study the beetle fauna of a cultivated farmland and tropical rainforest plot at the Permanent. Site of Nnamdi Azikiwe University, Awka for a twelve-month period using the pitfall technique. Eight pitfall traps made up of plastic containers with mouth diameters of 9.80 cm and 6.20 cm deep were set monthly at random in the two sampling sites. The traps, which were filled to one­ third with 5 % formalin, serving a preservative, were recovered after twenty-four hours and the insects caught sorted and counted under a dissecting microscope. Species of beetle obtained from the cultivated plot were Macrocheilus labrosus, Hyparpalus sp., Carpophilus fumatus, Podagrica uniforma, Tetragonothorax sp., Chlaenius sp., Pheropsophus parallus, Silidas apicalis, Tenebroides mauritanicus, Heteroderes sp., and Heterorynchus licas while only Hyparpalus sp., and Mylabris sp., were obtained from the fallow plot. The result of Fisher's Least Significance Difference (F-LSD) test shows that the pitfall catches of beetles from the two sampling sites were significantly different at p-value of 0.0002 and mean difference of 3.417. The heterogeneity of the beetle species at the cultivated plot was traced to nature of vegetation and mode of life of the beetle species. The role of certain beetle families as faunal indicators was highlighted. Other factors, which influenced the beetle species at the arable plot and their non-trapping at the forest ecosystem, were also discussed.