The present study was carried out to document the species diversity, abundance of Lycaenidae butterflies and their host plants during the year January 2016 to December 2017 in Annamalainagar using transect counting method. There were 15 genera and 16 species of lycaenid butterflies observed from Annamalainagar area and grouped under 3 subfamilies namely Polyommatinae, Theclinae, Curetinae and four Tribes viz., Polyommatini, Loxurini, Arhopalini and Amblypodiini. Out of which, nine species were found common and three species were very common based on their relative abundance. There were 20 plant species were observed as important larval host plants species of lycaenid butterflies viz., Cajanus cajan, Vigna sinensis, Zizphus jujube, Ziziphus mauritiana, Vigna radiate, Pongamia pinnata, Crotalaria spp., Amaranthus spinosus, Tribulus terrestris, Zornia gibbosa, Sesbania bispinosa etc., and majority of them were belong to the Fabaceae family, which supplies food for their survival in Annamalainagar area.
