Study about various Diseases of silk worm, their occurrence and management : A Review

Abstract

Silkworm Diseases and Pest Control Diseases are the behavioral and physiological changes induced by pathogens in an organism. All diseases have specific symptoms and characteristics. Similarly, silkworms are also affected by various types of diseases caused by protozoa, fungi, bacteria and viruses. Since they cause substantial financial loss to the industry, their prevention and control assumes utmost importance. Pebrine: Pebrine is caused by a protozoan called Nosema bombycis. In the initial stages the larvae appears to be healthy, but when observed under a microscope we can see oval, shinning spores of Nosema. Pebine disease is infected to the silkworms in two methods; peroral and transovarial infection. In advanced stages of infection, silkworms stops feeding resulting in unequal size larvae, they become sluggish, and die. The dead larvae turn black in colour due to secondary bacterial infection. If infection occurs in late V instar, the larvae spin the cocoons, and the moth may also emerge. Infected female moths lay pebrine contaminated eggs in lumps one above the other. The number of eggs per laying is also drastically reduced.