author(s)
Krishna Talukdar, Sunayan Bordoloi and Salma Mazid

abstract
Lead is a widespread heavy metal and environmental pollutant which is released into the environment as automobile exhaust. It is toxic and affects different organisms including plants and animals. The present study was conducted to investigate the effect of lead on the haemogram of eri silkworms as haemogram serves as an indicator of the physiological status of an organism. Lead in the form of inorganic salt, lead nitrate was added to castor leaves at three different concentrations and fed to the 4^th and 5^th instar larvae of eri silkworm for 3 days to evaluate their effect. The data revealed that Total Haemocyte Count (THC) and Differential Haemocyte Count (DHC) of larvae treated with lead nitrate were affected. Significant reduction in THC was recorded in both 4^th and 5^th instar larvae as compared to normal larvae. DHC of all the different haemocytes (PR, PL, GR, SP, OE) decreased more or less as compared to normal. Blood volume of the treated larvae also decreased slightly but the reduction was not significant.