Studies On The Epizootic Dynamics Of Dendrolimus Spectabilis Cytoplasmic Polyhedrosis Virus

Based on the bioassay of Dendrolimus spectabilis Cytoplasmic Polyhedrosis Virus(DsCPV) against Dendrolimus punctatus. the selection effect of DsCPV on different instars of D. punctatus, the effect of DsCPV on D. punctatus under different temperature, the control action of different dosages of DsCPV on the host population in field, the epizootic dynamics of virus disease in field, and the influence of different concentrations of DsCPV on the parasitism nature enemy of the pupa of D. punctatus were studied The results showed that after ingesting virus on the concentration of 1.2 X 106PIBs/ml. from 1st instar to 5th instar, the mortality percentage of D. punctatus larvae were 75.7%, 85.0%, 95.0%, 60.0%, 50.0% ; The mortality velocity of D. punctatus larvae increased with temperature of treatments, but the mortality rate didn't; 24 days after spraying virus on the concentrations of 2.5 X 10"PIBs/mI~2.5 X 107PIBs/ml. the decline rate of host population in field were 83.1%, 92.8%> 93.1%; The data of bioassay and the mortality rate of host after spraying virus in field could be quite simulated by time-dosage-mortality model. The predicted values well fitted with observed data, the modeling equation of bioassay passed Pearson Chi-Square test and Hosmer & Lemoshow test, the modeling equation of the mortality rate of host after spraying virus in field passed Hosmer & Lemoshow test, and T-test indicated the parameters of equations reached significant le\el(P<0.001). The model could be used to predict the daily disease death rate of present generation population of host. There were negligible variations between the parasitic percent of the pupa of host treated by virus and that's of contrast, directly side effects of DsCPV on the parasitism nature enemy of D. punctatus in pupa stage could be neglected.