球孢白僵菌对葱地种蝇成虫的毒力及繁殖力的影响

本文采用浸虫法测定了4株球孢白僵菌对1日龄葱地种蝇（本文称葱蝇）成虫的毒力，筛选出高致病力的菌株，描述了感染症状，测定了其亚致死剂量LC₂₀和LC₅₀对存活1日龄葱蝇成虫生物学参数和繁殖力的影响，并比较了5.8×10³和5.7×10⁵孢子/mL对1日龄和10日龄葱蝇成虫死亡率和单雌产卵量的差异。结果表明菌株Bb01对葱蝇成虫的致病力最强，其LC₅₀为1.76×10⁶孢子/mL，其次为菌株Bb03和Bb02，其LC₅₀分别为4.05×10⁶和1.86×10⁷孢子/mL。与对照相比，菌株Bb01亚致死剂量处理1日龄成虫后，明显延迟了葱蝇成虫的产卵前期，降低了单雌产卵量，LC₂₀浓度处理时单雌产卵量比对照下降了51.9%，LC₅₀处理下降92.2%，明显缩短了雌成虫寿命，但卵孵化率没有明显影响。虽然菌株Bb01对1日龄成虫造成的死亡率较高，但在5.7×10⁵孢子/mL下，10日龄成虫单雌产卵量比对照下降了82.5%，对种群控制效果仍较强。

Virulence of Beauveria bassiana to Adults of Delia antiqua (Meigen) and Effects on Their Reproduction

The virulence of 4 strains of Beauveria bassiana to 1-day-old Delia antiqua (Meigen) adults was detected with insect-dipping method to screen out strains of high pathogenecity. The reproduction and biological parameters were measured to D. antiqua treated with the sublethal dose LC₂₀ and LC₅₀, and effects of the strains on mortality and fecundity of age-specific D. antique adults were compared between treatments by 5.8×10³ and 5.7×10⁵ conidia/mL concentrations. The strain B. bassiana Bb01 showed the highest virulence against D. antique, with LC₅₀ of 1.76×10⁶ conidia/mL, followed by B. bassiana Bb03 and Bb02, with LC₅₀ of 4.05×10⁶ and 1.86×10⁷ conidia/mL, respectively. B. bassiana Bb01 extended preoviposition period of 1-day-old D. antiqua adults and reduced their fecundity by 51.9% and 92.2% at LC₂₀ and LC₅₀ compared with the control, respectively. B. bassiana Bb01 shortened longevity of female adults significantly, while had no effect on egg hatching rate. Although Bb01 caused higher mortality in 1-day-old adults than in 10-day-old adults, fecundity of 10-day-old adults was reduced by 82.5% at 5.7×10⁵ conidia/mL of Bb01 compared with the control.