Abstract: A cytoplasmic po3.yhedrosis virus was found to cause infections to D. qrotei. a defoliator of various ornamental plants in FuJian Province. The virus infected only the mid-gut of larvae. It ia hexagen or approximately round in shape with different sizes. The polyhedrons are irregular. The virus has an average diameter of 1.3-2.0 u. It is classified to belong to Reoviridae, Cypovirus.