防治棉铃虫的杀虫抗生素筛选及其作用方式

SCREENING TESTS AND PRELIMINARY STUDY ON THE INSECTICIDAL ANTIBIOTICS AND THEIR EFFECT IN CONTROLLING HELICOVERPA ARMIGERA

作者进行了50多种抗生素对棉铃虫的毒力测定和有关作用方式的探讨。结果表明,在触杀和胃毒试验中,仅Avermectin的系列显示出明显的毒力效果,其中B_1组分效果尤为突出。触杀和胃毒作用两方面相比,72h的胃毒LC_(50)为432mg/L/g幼虫,比触杀LC_(50)(3782mg/L/g幼虫)约高9倍。但速效性较差,持效性较好。在生长抑制试验中,仅Allosamidin表现出明显的生长抑制效果。处理后的第6天,40mg/L处理的幼虫体重(38.06mg/头)只相当于CK(279.40mg/头)的1/7;体长(19.7mm/头)只相当于CK(25.4mm/头)的77.5％;化蛹率仅为7.2％,而CK为93.1％。在驱避试验中没有任何抗生素显示出较好的效果。

The writers have studied the toxicity and the relative effects of more than fifty antibiotics to cotton bollworm. The results showed that only Avermectin series have obvious toxic effect to cotton bollworm,especially Avermectin B1 component. Comparing the function of contact and stomach poison, the LC50 (432mg/L/g, larvae) of stomach poison in 72 hours was about nine times as much as the LC50(3782 mg/L/g,lar-vae) of contact. Although the stomach poison action was inferior but showed better persistency. In inhibiting growth trial,only Allosamidin showed strong stress. In 6th day of 40 mg/L treatment,the larval weight (38. 06 mg/larvae)was equivalent only to one-seventh of that in the check(279. 40mg/larvae) ;and the body length (19. 7mm/larvae) of treated larvae was 77. 5% of those in check (25. 4mm/larvae) ;the pupation rate of treated larvae was only 7. 2%,much lower than that of check (93. 1%). As to repellent action test,none of antibiotics showed good control effect.