Survey on Simulium Species (Diptera: Simuliidae) and Abundance in Relation with Water Quality at Lalitpur District, Kathmandu

Abstract

Six months study (Oct, 2007 –March, 2008) was carried on black-flies at three sites (Godawari River, Nakkhu River and Karmanasa River) of Lalitpur District here by designated as site I, site II and site III respectively. Out of a total of 952 samples collected, only 729 were identified on the basis of larval, pupal and adult morphological features into four different species of Simulium i.e S. (Simulium.) variegatum gr., S. (S.) multistriatum gr ., S (S.) tuberosum gr. and S (S.).indicum. Study on monthly variations was exposed to significant variation of black-fly species in every month in site I and II but no record of the fly in site III was made throughout the study period. Common type of species diversity in site I (H¯=1.154) and II (H¯= 1.50) was recorded due to alike environmental factors in those sites and January appeared to be the most suitable month for the abundance of species while October as the least. Present study also justified the accountable relationship of species with temperature; DO and water current in both site I and site II.