Preliminary Research on the Incidence Characteristics of Prodenia litura (Fabricius) in Bt Transgenic Cotton Field

The harm to Bt transgenic cotton leaves and reproductive organs caused by Prodenia litura (Fabricius)was greater than that to non-transgenic cotton.The number of larvae per 100 transgenic cotton plants was four times more than that in on non-transgenic cotton plant.There were 3 reasons that may lead to:①there was no obvious difference between Kemian-1 and Yumian-1 in the rate of damage to leaves, flowers and buds due to Prodenia litura(Fabricius),②Prodenia litura (Fabricius) fed on Bt transgenic cotton leaves had a higher ratio of female to male,a higher ovipositing ratio and more eggs,and ③ the incidence of Prodenia litura(Fabricius) had a close relationship with the vegetative condition of cotton plants. Close attention must be paid to the chemical control of Bt transgenic cotton and especially more nitrogen, phosphorous and potassium are applied.