Abstract: With electron microscope, most of the occlusion bodies of CiEPV are ellipictal in shape, some are square-round. They vary greatly in size. The virions are oval and mulberry-like in appearance. The core of the virion is cylindrical. From the longitudinal section , its inner ropelike structure folds back 2 or 3 times and from its cross section, 2 or 3 dots can be observed. The lateral body is also cylindrical and symmetrically encloses the nucleocapsid. This viral DNA, when cleaved with restriction enzyme EcoR I, produces 16 DNA fragments.The molecular weight of this DNA is 135.7×10⁶ daltons. Degradation of the occlusion body of CiEPV is faster than that of OaEPV under the same condition. When the temperature is constant at 37℃ and pH ranges within 9-11.5, with the higherpH, the degradation of occlusion body becomes faster. When the pH is constant at 11.2 and the temperature ranges within 25-40℃, with the higher temperature, the degradation of occlusion body becomes faster.

Key words: grasshopper, Calliptamus italicus entomopoxvirus, restriction endonuclease analysis