甜菜夜蛾和斜纹夜蛾等是近年来在蔬菜上发生普遍，危害较重的鳞翅目夜蛾科害虫。它们的食性较杂，寄主极多，除蔬菜外，还危害棉花、玉米、甘薯、大豆及多种花卉、牧草和草坪等。这类害虫对一般药剂常表现较大的耐药性，导致用药量较高，进而产生抗药性。苏云金杆菌（Ｂｔ... Spodoptera exigua and Spodoptera exigua are common and harmful pests of Lepidoptera in vegetables in recent years. Their food is more complex, a host of extremely many, in addition to vegetables, but also endanger cotton, corn, sweet potatoes, soybeans and a variety of flowers, pastures and lawns. Such pests often show greater resistance to the general agent, resulting in higher doses, and then produce resistance. Bacillus thuringiensis (Bt ...