Broad-spectrum pesticides and Bt crops have been used against the cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), but their effect on the environment and the development of resistance are the main limitations for these control measures. The use of mycobiopesticides is an ecofriendly and efficient alternative. Fungicides have a wide distribution and a high genetic variability, which allows their screening for more virulent isolates. Therefore, the objective of this work was to evaluate the interactions of H. armigera larvae with Metarhizium anisopliae and Beauveria bassiana, on mortality, virulence, sublethal effects, and life table aspects. The isolates that caused mortality rates of H. armigera above 80% were selected for further assays. Virulence was measured by LC50 estimates, using Probit analysis to sublethal effects, and the bootstrap procedure to estimate the biological parameters: time for development, fertility, longevity, pre-ovipositional period, egg viability, and sex ratio. The H. armigera mortality rates caused by B. bassiana and M. anisopliae ranged from 45 to 100% and from 40 to 90%, respectively. Longevity, fertility, and survival rates are affected in all treatments. The pupal weight of individuals treated with fungi was lower than in the control. Deformations were observed in H. armigera pupae developed from larvae treated with B. bassiana. The use of sublethal concentrations of isolates of M. anisopliae and B. bassiana resulted in an adverse effect on the biological parameters of H. armigera.

中文翻译：

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不同真菌分离物对棉铃虫的亚致死作用（鳞翅目：夜蛾科）

广谱农药和Bt作物已被用于对抗棉铃虫Helicoverpa armigera（Hübner）（鳞翅目：夜蛾科），但它们对环境的影响和抗药性的发展是这些控制措施的主要局限性。杀真菌剂的使用是一种生态友好且有效的替代方法。杀菌剂的分布范围广，遗传变异性高，因此可以筛选出更具毒性的分离物。因此，这项工作的目的是评估棉铃虫幼虫与间日疟原虫和球孢白僵菌的相互作用，以研究其死亡率，毒力，亚致死作用和生命表方面。选择导致棉铃虫死亡率高于80％的分离株进行进一步测定。毒力是通过LC50估算值来衡量的，使用Probit分析得出亚致死作用，通过引导程序估算生物学参数：发育时间，生育力，寿命，排卵前时期，卵子存活率和性别比。由球孢杆菌和无芒分枝杆菌引起的棉铃虫死亡率分别为45％至100％和40％至90％。所有治疗方法均会影响寿命，生育率和存活率。用真菌处理的个体的p重量低于对照组。在用球孢杆菌处理的幼虫发育的棉铃虫中观察到变形。在亚致死浓度的分离的分枝杆菌和球孢杆菌中使用亚致死浓度对棉铃虫的生物学参数产生不利影响。和性别比例。由球孢杆菌和无芒分枝杆菌引起的棉铃虫死亡率分别为45％至100％和40％至90％。所有治疗方法均会影响寿命，生育率和存活率。用真菌处理的个体的p重量低于对照组。在用球孢杆菌处理的幼虫发育的棉铃虫中观察到变形。在亚致死浓度的分离的分枝杆菌和球孢杆菌中使用亚致死浓度对棉铃虫的生物学参数产生不利影响。和性别比例。由球孢杆菌和无芒分枝杆菌引起的棉铃虫死亡率分别为45％至100％和40％至90％。所有治疗方法均会影响寿命，生育率和存活率。用真菌处理的个体的up重量低于对照组。在用球孢杆菌处理的幼虫发育的棉铃虫中观察到变形。在亚致死浓度的分离的分枝杆菌和球孢杆菌中使用亚致死浓度对棉铃虫的生物学参数产生不利影响。在用球孢杆菌处理的幼虫发育的棉铃虫中观察到变形。在亚致死浓度的分离的分枝杆菌和球孢杆菌中使用亚致死浓度对棉铃虫的生物学参数产生不利影响。在用球孢杆菌处理的幼虫发育的棉铃虫中观察到变形。在亚致死浓度的分离的分枝杆菌和球孢杆菌中使用亚致死浓度对棉铃虫的生物学参数产生不利影响。