Bioassay of Clostera anastomosis granulosis virus

Abstract

The second-instar healthy larvae of Clostera anastomosis were collected in the artificial woodland of poplar in Shuangcheng Town, Heilongjiang Province, China. The dead larvae of C. anastomosis infected by granulosis virus (GV) of Clostera anastomosis were grinded to obtain GV. The GV viral pesticide was diluted to seven concentrations, 1.58×103PIB·mL−1, 1.58×104 PIB·mL−1, 1.58×105 PIB·mL−1, 1.58×106 PIB·mL−1, 1.58×107 PIB·mL−1, 1.58×108 PIB·mL−1 and 1.58×109 PIB·mL−1 and the fresh poplar leaves were dipped in the seven concentrations liquids to feed the larvae. After nine days the mortality of larvae was investigated. The minimum corrected mortality (7.32%) of larvae was observed at concentrations of 1.58×103PIB·mL−1 and the maximal mortality (97.36%) was observed at concentration of 1.58×109 PIB·mL−1. The regression equation between the logarithm of the virus concentration and the mortality was y=1.946+0.558x. The LC50 was 2.97×105PIB·mL−1. The LT50 for the virus concentration of 1.58×105, 1.58×106, 1.58×107, 1.58×108, 1.58×109 PIB·mL−1 were 8.55d, 6.89d, 5.9d, 4.65d, and 4.08d, respectively, shorting gradually with the concentration increasing. It is concluded that the toxicity of Clostera anastomosis GV is very strong and as a kind of insecticides it has big potential in practical application.