微生物农药对新疆棉铃虫的防治效果

对Bt杀虫剂、新棉安和生霸1号三种微生物农药在新疆棉田对棉铃虫的防治效果进行了试验.喷施微生物农药后幼虫的转移危害活动减少,生霸1号有明显的保蕾保铃效果;新棉安和Bt杀虫剂有一定的保铃效果,但受害蕾数量上升.对幼虫的杀虫效果,生霸1号最佳,其次为新棉安,而Bt杀虫剂最差.被Bt和HaSNPV感染的残存幼虫可以完成正常发育,死亡率上升缓慢,可以继续造成一定危害.棉田使用新棉安和生霸1号,喷药当时到24h后均可保持很高杀虫效果,而48 h后效果明显下降,72h后效果急剧下降.

Studies on Cotton Bollworm Control with Microbial Insecticides

Field and laboratory tests were conducted to evaluate the effectiveness of one Bt insecticide and two HaSNPV-based insecticides, Xinmianan and Shengba 1, against cotton bollworm in 1997, in Shache county, Xinjiang Province. The spray of these microbial insecticides caused reductions in the transferring activity of larvae and in the number of damaged cotton reproductive organs. Shengba 1 provided good protection to both squares and bolls (including flowers), while Bt insecticide and Xinmianan only gave protection to bolls (including flowers) in some degree. To depress the number of larvae, Shengba 1 is best, Xinmianan is second, Bt insecticide is poor. The infected survival larvae can finish development normally, with their mortality increased slowly, therefor they can still do some damages. The effectiveness of Shengba 1 and Xinmianan can maintain high effect to kill the cotton bollworm in 24h, then decrease obviously 48h, and sharply 72h after spraying in cotton field.