Investigation into the effect of altitude on the differential hemocyte count of circulating plasmatocytes and granulocytes of larval stage of Antheraea assama (Lepidoptera: Saturniidae)

Abstract

Differential hemocyte count of circulating plasmatocytes (PL) and granulocytes (GR) of fifth-instar larvae of Muga Silkworm Antheraea assama Westwood (Lepidoptera: Saturniidae) reared at four different sericulture farms situated at different altitudes, viz, Khanapara State Sericulture Farm, Assam, altitude 55.5m above sea level (ASL); Nongpoh (Central Silk Board farm), Meghalaya, altitude 464m ASL; Tura (Central Silk Board farm), West Garo Hills, Meghalaya, 657m ASL; and Kalimpong (Central Silk Board farm), West Bengal, altitude 1,247m ASL, were calculated and compared to investigate the effect of altitude on the number of PL and GR per mm3 of larval hemolymph. The investigation showed that the mean circulating PL and GR were highest at Khanapara (55.5m ASL) located at the lowest altitude, whereas their numbers gradually decreased with increase in altitude at Nongpoh (464m ASL), Tura (657m ASL), and Kalimpong (1,247m ASL). This may be attributed to the average environmental temperatures observed at different altitudes, which may affect the overall hemocyte load of larval stages reared at those altitudes.