Institut Sophia Agrobiotech, Université Côte D'Azur, INRAE, CNRS, ISA, 400 route des chappes, 06903, Sophia Antipolis, France.
Sci Rep. 2020 Oct 1;10(1):16241. doi: 10.1038/s41598-020-73145-6.
Bioinsecticides based on Bacillus thuringiensis (Bt) spores and toxins are increasingly popular alternative solutions to control insect pests, with potential impact of their accumulation in the environment on non-target organisms. Here, we tested the effects of chronic exposure to commercial Bt formulations (Bt var. kurstaki and israelensis) on eight non-target Drosophila species present in Bt-treated areas, including D. melanogaster (four strains). Doses up to those recommended for field application (~ 10 Colony Forming Unit (CFU)/g fly medium) did not impact fly development, while no fly emerged at ≥ 1000-fold this dose. Doses between 10- to 100-fold the recommended one increased developmental time and decreased adult emergence rates in a dose-dependent manner, with species-and strain-specific effect amplitudes. Focusing on D. melanogaster, development alterations were due to instar-dependent larval mortality, and the longevity and offspring number of adult flies exposed to bioinsecticide throughout their development were moderately influenced. Our data also suggest a synergy between the formulation compounds (spores, cleaved toxins, additives) might induce the bioinsecticide effects on larval development. Although recommended doses had no impact on non-target Drosophila species, misuse or local environmental accumulation of Bt bioinsecticides could have side-effects on fly populations with potential implications for their associated communities.
基于苏云金芽孢杆菌（Bt）孢子和毒素的生物杀虫剂作为控制害虫的替代方案越来越受欢迎，但其在环境中的积累对非靶标生物可能产生潜在影响。在这里，我们测试了慢性暴露于商业 Bt 制剂（Bt var. kurstaki 和 israelensis）对在 Bt 处理区域存在的 8 种非靶标果蝇的影响，包括 D. melanogaster（4 个品系）。高达推荐田间应用剂量（~10 个集落形成单位（CFU）/g 蝇培养基）的剂量不会影响蝇的发育，而在该剂量的 1000 倍以上则没有蝇出现。在推荐剂量的 10 到 100 倍之间，剂量依赖性地增加了发育时间并降低了成虫出现率，且具有种间和株间特异性的影响幅度。聚焦于 D. melanogaster，发育改变是由于龄期依赖性幼虫死亡率引起的，并且在整个发育过程中暴露于生物杀虫剂的成虫的寿命和后代数量受到适度影响。我们的数据还表明，制剂化合物（孢子、裂解毒素、添加剂）之间的协同作用可能会对幼虫发育产生生物杀虫剂的影响。尽管推荐剂量对非靶标果蝇没有影响，但 Bt 生物杀虫剂的滥用或局部环境积累可能会对蝇种群产生副作用，从而对其相关群落产生潜在影响。
