Amidst global warming and anthropogenic impact, sensitive aquatic organisms in different ecosystems are indispensable. For this reason, the two habitats succeeding (aquatic in larval life and terrestrial life) black fly is so important and some species of their female adult act as a potential vector for onchocerciasis disease to human. Hence, the present study is aimed to assess the black fly in tropical streams along with environmental factors. Twelve species were found from 42 sampled streams and rivers different region of Eastern and Western Ghats, Peninsular India. The individual black flies were highly abundance recorded in Simulium ruficorne species group of S. (N.) kiliyurense (32.7%). The active observation of PCA shows that F1 (53.86%) had the high value than F2 (11.34%). Squared cosines of the variables value clearly indicating lower site of Thirumoorthy falls (0.046) and the higher site of Kiliyur falls (0.028), where these tourist part had more individual black fly larvae. Spearman′s rs correlation coefficient, and this result indicated that water temperature, leaf litter and total dissolved solids had the significant value (γ = 0.79058, 0.734682, 0.41112) with abundance of black flies. The results of one-way ANOVA revealed that the relative abundance of black flies was significant (F = 77.13, p = 3.3) between the sampling sites. Environmental factors were influenced with larval distribution and abundance varied with stream air temperature, water temperature, conductivity, total dissolved solids and salinity observed in the present study.