SEASONALITY AND ABUNDANCE OF INSECTS WITH SPECIAL REFERENCE TO BUTTERFLIES (LEPIDOPTERA: RHOPALOCERA) IN A MOIST DECIDUOUS FOREST OF SIRUVANI, NILGIRI BIOSPHERE RESERVE. SOUTH INDIA

Abstract

The present study describes the seasonal variations in the abundance of insect groups in a natural moist deciduous forest of Western ghats, South India. The study covers the seasonal abundance patterns of six major insect orders, namely Coleoptera, Lepidoptera, Hemiptera, Diptera, Orthoptera, and Hymenoptera and also the seasonality of 53 species of butterflies (Lepidoptera; Rhopalocera). The relationship of insect abundance with the prevailing abiotic and biotic conditions has been examined. Three major sampling methods, namely sweep sampling, knockdown sampling and light trapping were used for the general insect sampling, while transect counting method was employed for the estimation of butterfly abundance. Other methods involving direct and indirect visual estimation of insect abundance employed in the field in an experimental basis for relatively shorter durations are also described.