Abstract: Apriona swainsoni(Hope), eating branch and stem of trees, is one of the most serious forest plant quarantine pests in China. Study results showed that once the larvae bored into xylem of trees, it was very difficult to control them by any preventive measure. So it is very important to forecast accurately ovipositing occurrence time of Apriona swainsoni (Hope). Based on the results observed and measured by feeding in condition of variable and constant temperature during 1997～1999,initial temperature for egg development(C), effective accumulated temperature(K) and theoretical equations (Y and N) were found and put forward. They were respectively C=12.29±3.10 or C=12.26±0.81 or C=12.02±1.57;K=164.63±32.12 or K=174.67±9.02 or K=175.52±16.30, Y=12.29±164.42X, r=0.9831>r_0.01=0.6055 or Y=12.26±174.67X, r=0.9910>r_0.01=0.6835 or Y=12.02±175.52X, r=0.9334>r_0.01=0.4487. Prediction formulation: N=164.42±32.12T-(12.29±3.10) or N=174.67±9.02T-(12.26±0.81) or N=175.52±16.30T-(12.02±1.57). It was more simple and practical to feed them in condition of variable temperature. It will be more rationalization and accuracy using the method of weighted variable temperature.

Key words: Apriona swainsoni, Sophora japonica, Ovipositing occurrence time, Forecast