The Reserve houses about 160 species of butterflies including endemic and rare species. Among them, about 19 species, commonly seen in the Western Ghats, are found in the moist deciduous forests. The common species found here include the Lime Butterfly, the Malabar Tree Nymph and so on.
Among the rare species is the Travancore Evening Brown (Parantirrhoea marshalli) endemic to the southern Western Ghats, that was identified here after a gap of several decades. The species was first discovered by the Englishman, Harold S Ferguson.
A wide variety of moths including the Lunar moth and the Atlas moth, the largest moth species in the world, are also found in the area.