Bioassay of Clostera anastomosis Granulosis virus

摘要

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, 1.58x10~3PIB · mL~(-1), 1.58x10~4 PIB · mL~(-1), 1.58x10~5 PIB · mL~(-1), 1.58x10~6 PIB · mL~(-1), 1.58 x 10~7 PIB · mL~(-1), 1.58 x 10~8 PIB · mL~(-1) and 1.58x10~9 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 x 10~3 PIB · mL~(-1) and the maximal mortality (97.36%) was observed at concentration of 1.58 x 10~9 PIB · mL~(-1). The regression equation between the logarithm of the virus concentration and the mortality was y=1.946+0.558x. The LC_(50) was 2.97 x 10~5 PIB · mL~(-1). The LT_(50) for the virus concentration of 1.58 x 10~5, 1.58 x 10~6, 1.58 x 10~7, 1.58 x 10~8, 1.58 x 10~9 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 toxic-ity of Clostera anastomosis GV is very strong and as a kind of insecticides it has big potential in practical application.