Abstract
The study showed the incidence of mosaic in squush fields in Ninevah province at high percentage veached to 100% at autumn season/2002,and this was associated with high population of two species of aphids, Myzus persicae and Aphis craccivora which regarded as a more important vectors of squash viruses . Zucchim yellw mosaic virus and Cucumber mosaic Cucumovirus were identified as a causal agents of squash mosaic These viruse were diagnosed by indicator plants and serologically by agglutination test by using antisera of ZYMV and CMV. The results of permanent samples of thin sections examined by electron microscope revealed deformations in infected squash cells and organelles, and presence of crystal bodies in cytoplasm.
