Distribution of Social Spider Stegodyphus Sarasinorum along the Altitudinal Gradient of Nilgiri Biosphere Reserve

Stegodyphus sarasinorum is a common social spider found in India. It has the ability to control the pest. It is found in the fencings of the agricultural fields and road sides. The present investigation was carried out to find the distribution of S. sarasinorum population along the attitudinal gradient of Nilgiri Biosphere Reserve (NBR). Twelve different stations were selected for the present study from 918m above msl to 2262 above msl. The results reveals that the S. sarasinorum is absent in altitude above 1441m above msl while in the lower altitude places the number of webs of S. sarasinorum was more. Highest frequency of nests was found in Vazhaithottam (925 above msl). The relationship between the number of nests/ 100 m transect as well as nest size with altitude was derived using Curve expert software and presented. The present study reveals that S. sarasinorum do not exist in higher altitudes.