Chemical Control of Natural Population Dynamics of Plutella xylostella in Winter in Qiongzhong County, Hainan Province

Diamonback moth(Plutella xylostella L.) often breaks out in the main vegetable and melon producing areas in Hainan Province. The survey showed the yield decreased by 35 %～60 % due to the damage caused by the diamondback moth. Chemical control of the natural population dynamics of the diamondback moth was carried out in winter in November to December 2008 in the vegetable producing base in Shenbo Village, Yingen Town, Qiongzhong County. The results found that Abamectin+Indoxacarb 4.75 % WP could control the diamondback moth more effectively, rapidly and sustainably than other insecticides under trial. Emamectin benzoate 0.2 % EC and Abamectin 2 % EC could also control early but not the last instar larvae effectively. This shows that spraying vegetables at the early instar larval stage with Abamectin+Indoxacarb 4.75 % WP(1: 1 000～1 500) and Emamectin benzoate 0.2 % EC(1: 1 000) can effectively control the diamondback moth.