The life table grouped in various factors,the index of population trend and the index of population control are used as the basic methods to evaluate the effectiveness of PxGV on the population dynamics of P.xylostella (L.) The results showed that,PxGV gave a good effect on the population dynamics of P.xylostella. The index of population trend was 0 97 The index of population trend in the treatment of spraying PxGV was 0.19 against that in control.The index of population trend in treatment of s...