Abstract: In an experimental population of English grain aphid, the development rate V(t) of alatae is lower thanthat of apterae, and the V(t)of 4th instar of alatae is the Iowest. The alatae appears to be able to toler-ate a wider range of temperature,but the survival curve is affected evidently by it. At low temperature,the curve declines slowly, but at high temperature, the curve declines abruptly. The expected farTowingrate with age may be modeled by modified normal distribution. At high temperature, the peak of curvecomes early,there is a higher rate of farrowing,and reproductive period is shortened.

Key words: carabid, spatial distribution, pest control, agricultural landscape.