IDENTIFICATION OF MORPHO-VARIANTS OF PLASMATOCYTE IN HAEMOLYMPH SMEARS OF ANTHERAEA MYLITTA AND ITS IMMUNE RESPONSES.

The most decisive hemocyte type ?plasmatocyte? is recognized to carry out a variety of functions viz. phagocytosis, encapsulation, nodule formation, injury repairing and metabolism. In the present study, seven types of PLs variants were identified in haemolymph smear of Antheraea mylitta. The PLs were categorized from other hemocytes by their relatively large size, high nucleo-cytoplasmic ratio, presence of pseudopods/filopods etc. and they were visible all through larval-pupal development. The PLs variants were identified also on the basis of their morphology and immunological function towards stress condition i.e. starvation, chilling, heating and disease. Interestingly, PLs variants showed stage and age specific variation in cellular immune responses of tasar silkworm. More PLs variants were recorded under stress condition. The differential count of PLs variants varied considerably before and after moult. Much elongated cytoplasmic prolongations/pseudopods in some PLs variants were observed and its relative percentage showed an inverse rapport. Considerable alteration in temperature (high and low) resulted in appearance of more PLs variants and least number was recorded in pebrine infected insects. PLs variants are seen at different functional states of PLs. Interestingly differential profile of PLs variants fluctuates under stress condition without altering the total count of PLs. It is believed that these variants are morpho-types of PLs and involved in numerous physiological activities during larval-pupal development. Identification of PLs variants and their involvement in immune responses depending on the physiological state of A. mylitta possibly will help to perceive the impact of different stresses, disease, drug and disinfectant on health status.