Incidence of Bacterial and Viral Diseases of Silkworm, Bombyx Mori L. in Bangladesh and their Control

Abstract

Like other forms of life, the silkworm, Bombyx mori L. is also affected by various types of diseases. During the growth the silkworms come in contact with a number of pathogenic agents like virus, bacteria, fungus, protozoans etc. under natural environmental conditions. Life functions are thus interfered and a disease occurs. The ultimate result is the loss of worms and hence loss of cocoon production. The earliest scientific report on insect diseases was on silkworm ailments (Kirby 1826). Afterwards it was experimentally demonstrated that the micro­organisms are the causative agents for certain sickness in silkworms (Steinhaus 1963). A major breakthrough in our understanding of silk­worm disease was achieved by Pasteur (1885) who identified that the protozoan, Nosema sp. was responsible for the devastating disease ' pebrine' of silkworm (Rene Dubas 1960). Bacterial and viral diseases of silkworm are the most common diseases inhabiting all the silk producing countries and areas, although their severity varies with the consequent interaction of existing environment of different regions. Total crop losses due to these diseases are rarely known, but the cocoon yield is largely hampered affecting national plan as well as personal income. In any of the cases of bacterial or viral diseases, starting point is the individual silkworm from which the disease is spread to the population. The occurrence of disease in a population is the consequence of interaction between pathogen, host and the environment……………………….