Abstract: 【Aim】 This study aims to clarify the effects of Chouioia cunea venom on the cellular defense of hemocytes in Hyphantria cunea pupae. 【Methods】 Granulocytes of H. cunea pupa were separated by Na₂-EDTA treatment, and plasmatocytes were separated by nylon wool method. Cell culture in vitro was used to assess the effects of parasitoid C. cunea venom on encapsulation and phagocytosis of host H. cunea hemocytes. 【Results】 The encapsulation capacity of granulocytes of H. cunea was stronger than that of plasmatocytes. The encapsulation capacity of hemocytes was significantly inhibited by the parasitoid venom, and deceased gradually with the increase of venom concentration. The encapsulation capacity of both plasmatocytes and granulocytes increased at the beginning and then decreased gradually during the treatment of parasitoid venom. The encapsulation capacity of granulocytes in the treatment groups with different concentrations of venom reached to the maximum at 12 h after treatment. In the control group, the encapsulation capacity of plasmatocytes reached to the strongest at 15 h. However, the encapsulation capacity of plasmatocytes was the strongest at 12 h when they were treated by 0.01-0.03 VRE/μL parasitoid venom, while it was the strongest at 9 h when they were treated by 0.04-0.10 VRE/μL venom. The phagocytosis of C. cunea venom on granulocytes of H. cunea pupae was strongerthan that on plasmatocytes. The phagocytosis capacity of hemocytes was significantly inhibited by the parasitoid venom. However, the inhibition of plasmatocytes by the parasitoid venom was not as strong as that of granulocytes. 【Conclusion】 The venom of C. cunea can inhibit the encapsulation and phagocytosis of the granulocytes and plasmatocytes of H. cunea, and the cellular immunity significantly decreases with the increase of venom concentration.

Key words: Key words: Chouioia cunea, Hyphantria cunea, venom, cellular immunity, hemocytes, encapsulation, phagocytosis