Effect of temperature on the development,survival and fecundity of Spodoptera litura Fabricius

Instars number of larvae，the development，survival rate and fecundity of laboratory population of Spodoptera litura F．under various temperatures on a cabbage diet are studied．The results show that the numbers of larvae over 7 instars are 55.4％ ，41.2％ ，21.3％ ，16.6％ ，14.3％ at the constant temperature of 15℃ ，19℃ ，24℃ ，29℃ ，34℃ ，respectively The development threshold temperatures for egg，larvae，prepupae，pupae，precede period of egg oviposition are 11.52±1.78℃ ，11.97±0.91℃ ，12.52± 1.22℃ ，11.47±0.92℃ ，10.59±2.65℃ ，respectively．Their effective accumulated temperatures are 56.75℃ ／d，224.06℃ ／d，28.65℃ ／d，153.33℃ ／d，41.18℃ ／d，respectively．The development critical maximum temperatures are 38.2820℃ ，38.8766℃ ，39.5080℃ ，39.5403℃ ，37.4907℃ ，respectively The development critical minimum temperatures are 4.9509℃ ，4.8974℃，4.7435℃，4.7430℃,4.6471℃，respectively The most suitable temperatures are 23.0702℃ ，22 .0024℃ ，25.6765℃ ，26.5453℃ ，23.2649℃ ，respectively．The effect of temperature on the rate of each development stage and fecundity of female is significant．The survival rate of each development stage and fecundity of female increases with temperature as parabola．