[Histopathological studies of silworms (Bombyx mori Linn.) spontaneously infected with nuclear polyhedrosis].

Pathohistological changes in silkworms, spontaneously affected by nuclear polyhedry are investigated. The J-124 X C-122 hybrid after the fourth moulting is tested. After being subjected to a low temperature stress the silkworms were killed and material for pathohistological studies were taken from them. It is established that the most suitable tissues for the replication of the polyhedry virus of the silkworm were the cells of the fat bodies, the tracheal matrix and the hypoderm. Not all polyhedra form simultaneously. The virus as polyhedral bodies is detected in the infected tissues, cells respectively, on the 55th day (at the earliest) by the action of the low temperature stress. The histopathological investigation is recommended as a method for reliable and relatively early diagnoses.