苏云金杆菌亚致死浓度对绿豆象种群繁殖的影响

为明确苏云金芽孢杆菌对绿豆象Callosobruchus chinensis (Linnaeus)]种群繁殖力的影响,采用浸渍绿豆法对绿豆象成虫开展室内生测。结果显示：苏云金杆菌的剂量分别为80.0 IU/mg、53.3 IU/mg、32.0 IU/mg、26.7 IU/mg、20.0 IU/mg时,绿豆象成虫的致死率依次表现为95.56%、70.00%、36.67%、21.11%、7.78%,其毒力回归方程为y=0.38x+2.91。苏云金杆菌亚致死剂量LC₁₀、LC₃₀、LC₅₀可明显缩短绿豆象成虫的寿命、抑制雌成虫的产卵能力。亚致死剂量处理组绿豆象种群的净增值率、内禀增长率和周限增长率的值均低于对照组,亚致死剂量处理组种群的加倍时间显著延长。由此可见,苏云金杆菌对绿豆象有较好的杀虫效果,亚致死剂量对绿豆象种群的发育有明显的抑制作用。

Bacillus thuringiensis Sublethal Concentration: Effects on Population Reproduction of Callosobruchus chinensis (Linnaeus)

In order to determine the effect of Bacillus thuringiensis on the population reproduction of Callosobruchus chinensis, a laboratory bioassay was conducted on the adults of Callosobruchus chinensis by macerating method. The results showed that the fatality rates of adults were 95.56%, 70.00%, 36.67%, 21.11%, 7.78%, respectively, when the doses of Bacillus thuringiensis were 80.0 IU/mg, 53.3 IU/mg, 32.0 IU/mg, 26.7 IU/mg, 20.0 IU/mg, respectively. Its virulence regression equation was y=0.38x+2.91. LC₁₀, LC₃₀ and LC₅₀ significantly shortened the lifespan of the adults of Callosobruchus chinensis and inhibited the oviposition of female adults. After being treated by LC₁₀, LC₃₀ or LC₅₀, the net reproduction rate, intrinsic growth rate and finite rate of increase were lower than that of the control, while the population doubling time was prolonged obviously. It indicates that Bacillus thuringiensis has a good insecticidal effect, and the sublethal dose has a significant inhibiting effect on the population development of Callosobruchus chinensis.