Fig. 1
The symptoms of grasserie disease caused by Bombyx mori nucleopolyhedrovirus in the 5th instar larva, a healthy larva, b severely infected larva appearing yellowish in body color with turbid hemolymph containing BmNPV– OB (arrows), c, d cadavers of diseased larvae whereof d is hanging showing so-called tree top disease, and e Occlusion Bodies (OBs) observed under light microscope (40X magnification)