Influence of human activities on diversity and abundance of insects in Akure Forest Reserve, Ondo State, Nigeria

Abstract

This study was carried out to assess the impacts of human activities on insect diversity and abundance in Akure Forest Reserve, Nigeria. Three land uses (fallow land, cocoa agroforest and unlogged forest) were selected for field work within the forest reserve. An hectare block was centrally demarcated in each of the land use types where insects collection and enumeration of trees species took place. 13,578 insects distributed among 30 families belonging to 15 orders were collected and identified and preserved in the insect boxes in the Museum. Within the fallow land, a total of 5,182 insects belonging to 46 families and 8 orders were encountered, while in the cocoa agroforest, 5,884 insects distributed among 50 families and 10 orders and unlogged forest, consist of 2,490 insects distributed into 10 orders and 56 families. The families and order with the highest number of individual insects are Lepidoptera (4,000) and Orthopetera (1,260). These insects are mainly defoliators. The Shannon-weiner diversity index shows that unlogged forest is more diverse than the cocoa agroforest and fallow land. The tree species with the highest frequency per hectare is Cordia platythrsa (Boragiaceae) (6) in fallow land, Theobroma cacao (50) in cocoa agroforestry land Celtis zenkerii (Ulmaceae) in unlogged forest land. A total of 14, 26 and 41 species of tree were identified in the fallow land, cocoa agroforestry land and untouched forest respectively. Keywords: Biodiversity, agroforestry, insect defoliators, land uses, fallow land, conservation.