生物药剂防治两色绿刺蛾的研究

Study on the biological insecticides control to Latoria bicolor(Walker)

应用浸渍法选用5种不同浓度的白僵菌和苏云金杆菌,分别对两色绿刺蛾2龄初幼虫进行致病力测定,结果表明:白僵菌对2龄初幼虫致病力回归线方程为y=3.2363+0.2729x,其LC50为2.90×106孢子.ml-1,且5×106、5×107、5×108、5×109、5×1010孢子.ml-1不同浓度的LT50分别为8.62d、7.72d、7.25d、6.07d和5.66d。苏云金杆菌对2龄初幼虫致病力回归线方程为y=3.2889+0.2919x,其LC50为7.28105伴孢晶体.ml-1,且8×106、8×107、8×108、8×109、8×1010伴孢晶体.ml-1不同浓度的LT50分别为7.62d、5.87d、4.84d、4.33d和4.21d。根据正交试验均值最大值的组合原理,混合生物药剂的最佳组合为c1b2a3,即1%阿维菌素5000倍液+白僵菌20倍液+苏云金杆菌3000倍液;而混合生物与化学药剂的最佳组合为A1C2B2,即20%杀灭菊酯8000倍液+1%阿维菌素10000倍液+白僵菌20倍液,经林间应用防治效果较好。

The toxicities of five different concentrations Beauveria bussiana and Bacillus thuringieusis to early 2nd instars larvae of Latoia bicolor were determined in laboratory by dip method. The results showed that the toxicity regressive equation of Beauveria bussiana was y =3. 2363 ＋0. 2729x,and the values of LC50 was 2. 90 × 10^6spores·mL^-1. The values of LT50 of 5 ×10^6,5 × 10^7 ,5×10^5 ,5 × 10^9 ,5 × 10^10 spores· mL^-1 concentrations were 8. 62d,7. 72d,7. 25 d,6. 07d and 5. 66d,respectively. The toxicity regressive equation of Bacillus thuringiensis was y = 3. 2889 ＋ 0. 2919x, and the values of LC50 was 7. 28× 10^6ICPs· mL^-1. The values of LT50 of 8 × 10^6 ,8 × 10^7 ,8×10^7 ,8× 10^9 ,8× 10^10 ICPs · mL^-1 concentrations were 7. 62d,5.87d,4. 84d,4. 33d and 4. 21d, respectively. The best combination biological insecticides was clb2a3, mixed up with 5000 times of 1% adametim and 20 times of Beauveria bussiana and 3000 times of Bacillus thuringiensis . The best combination biological and chemical insecticides was A1C2B2, mixed up with 8000 times of 20% fenvalerate and 10000 times of 1% adamefim and 20 times of Beauveria bassiana. The effects of the clb3a3 and A1C2B2 were very good to control the larvae in field.