Although the forest teems with all kinds of insects and other invertebrate fauna, very little information is available on these groups of animals. So far only two groups of insect have been considered in depth viz. mosquitoes  and butterflies. However, the Sinharaja has featured prominently in surveys of Sri Lanka insect fauna conducted by the Smithsonian Institution. It is evident from these studies that there is much scope for detailed investigations of the invertebrates.

                            Studies on the mosquito fauna have shown that at least 27 species have been recorded as adults. The majority, 21 species, were found to breed in surface water sources. The rest used more specialised habitats for breeding. For instance Orthopodomia flavithorax and Culex uniforms breed in tree rot holes filled with water, while C. uniformis and Tripteroides affinis and a few other species use water filled bamboo culms. The most fascinating of all, are the two speciesTripteroides dofleini and Armigeres magnus that breed exclusively within the pitcher of Nepenthes distillatoria.

The butterfly fauna of the forest has only been listed, and so far 65 species have been recorded in the western sector of the forest. These include 2 endemic species and 19 endemic subspecies (Table 13). Among the common and more interesting butterflies one comes across in the forest are the Tree Nymph, a large black and white butterfly that inhabits the forest canopy, the Common Bird-wing reputed to be the largest butterfly in the country, the Clipper, the Cruiser and the most beautiful of all, the iridescent Blue-banded Peacock. One of the rarest species in Sri Lanka, the Five bar Swordtail, can also be seen during the months of March and April, the season of butterfly migration

 


Of some 65 butterfly species the Blue Mormom (Papilio crino) is the commonest one recorded in the Sinharaja Forest. The others include two endemic species and 19 endemic sub-species. One of the common and interesting butterflies that one comes across in the forest is the large black and white tree nymph, reputed to be the largest butterfly in the country.

A few common and interesting butterflies of Sinharaja.

                 * Endemic species 

Of the insects at sinharaja, of species interest are two endemic species of wasps of the family Loboscelidae. They are parasitic on Stick insects. The Sinharaja is the only known location where they have been recorded from the Asian region, the other centres of distribution of this family being New Guinea and Australia.