Insects and Butterflies in Kerala

Three out of every four organisms described so far are insects. This makes them the most numerous, if not the most dominant group of organisms on earth. Forest is the home for a large variety of them. In fact, most insects found in Kerala may have originated in the forests in the remote past, when much of the present day agricultural and urban lands were under forest cover. Therefore, a strict categorisation into forest and non-forest insects is not meaningful although there are some groups of insects found exclusively in forests, like beetles of the family Passalidae which inhabit the wet decaying timber on the floor of evergreen forests.

The Indian insect fauna were estimated at 67,000 species in 1980 of which 16,000 constituting about one fourth, were recorded from forests. The Kerala Forest Research Institute has a collection of about 3000 insect species from different forest habitats of which 900 have been authentically identified.

It is estimated that the recorded insects will be at least 6,000. In addition, many species remain unrecorded, of which many may turn out to be new species; particularly those from the forests. In a recent study of the butterflies and moths of Silent Valley, based on limited sampling representing about 20 sq.km of the 90 sq.km national park, 95 species of butterflies and 318 species of moths were recorded, but more significantly, 87 of the species collected (17%) could not be identified in spite of reference to the International Institute of Entomology of the Commonwealth Agricultural Bureau, London.