Abstract

Impact of forest disturbance on insect species diversity was studied at four location viz., Silent Valley, Nelliyampathy, Sholayar and Parambikulam. Incidence of fire (Silent Valley), plantation programmes (Nelliyampathy and Parambikulam) as well as forest cutting for fodder and firewood (sholayar) were the major disturbances. Silent Valley showed the highest plant diversity. The overall values of insect diversity was found to be the highest for Nelliyampathy. Forest disturbance had an adverse effect on insect diversity as indicated by the reduction in the diversity indices obtained for the disturbed sites. Altogether 1250 species of insects belonging to 15 Orders were collected from all localities, of which 586 species have been identified. Maximum number of species collected belonged to the Orders Lepidoptera and Coleoptera. It was concluded that all the areas contain more species than could be collected in this study, indicating the need for further investigations. Based on the extend and nature of disturbance, site specific conservation strategies are essential for protecting the biodiversity in the study areas