Programa de Pós graduação em Entomologia, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
Centro de Desenvolvimento Tecnológico, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
J Econ Entomol. 2019 Dec 9;112(6):2817-2823. doi: 10.1093/jee/toz218.
Bacillus thuringiensis (Berliner) has demonstrated potential use in insect pest management. We evaluated the toxicity and sublethal effects of formulations of toxic baits composed of bacterial isolates (Bt) B. thuringiensis var. oswaldo cruzi (Bto), B. thuringiensis var. israelensis (Bti), B. thuringiensis var. kurstaki (Btk), and B. circulars (Bc) in combination with three food attractants 50% grape juice, 7% sugar cane molasses, and 7% hydrolyzed protein on adults of Zaprionus indianus (Gupta, 1970), the main pest of fig fruit (Ficus carica) in Brazil. Likewise, we evaluated the toxicity on the parasitoids Trichopria anastrephae Lima, 1940 and Pachycrepoideus vindemmiae (Rondani, 1875) in ingestion bioassays. Adults of Z. indianus showed high susceptibility to Bacterial isolates. However, the Bto isolate (1013 CFU. ml-1) caused adult mortality of 100%, in 72 h after exposure, with LT50 values of ≈20 h. By using the lethal concentrations (LC90) of the Bto isolate, estimated via the concentration-response curves with the food attractants, a significant reduction (40 to 50%) in the total fecundity and in the embryonic viability of eggs from females fed with the toxic baits was observed. The food attractants + Bto (80 × 108 CFU. ml-1) did not cause significant mortality of T. anastrephae and P. vindemmiae adults (mortality < 20%). The bacterial isolates Bti, Btk, Bc, and Bto are considered promising for the formulation of toxic baits, because, besides providing toxic effect on adults of Z. indianus, they showed no toxicity on T. anastrephae and P. vindemmiae adults.
苏云金芽孢杆菌（ Berliner ）在害虫管理中具有潜在的应用价值。我们评估了由细菌分离物（Bt）组成的毒饵制剂的毒性和亚致死效应，这些分离物包括苏云金芽孢杆菌 var. oswaldo cruzi（Bto）、苏云金芽孢杆菌 var. israelensis（Bti）、苏云金芽孢杆菌 var. kurstaki（Btk）和苏云金芽孢杆菌 var. circulars（Bc），与三种食物引诱剂 50%葡萄汁、7%甘蔗蜜和 7%水解蛋白结合使用，这些制剂对巴西主要的无花果果实害虫 Zaprionus indianus（Gupta，1970）成虫具有毒性。同样，我们还在取食生物测定中评估了这些制剂对寄生蜂 Trichopria anastrephae Lima，1940 和 Pachycrepoideus vindemmiae（Rondani，1875）的毒性。Z. indianus 成虫对细菌分离物表现出高敏感性。然而，Bto 分离物（1013 CFU. ml-1）在暴露后 72 小时内导致成虫死亡率为 100%，LT50 值约为 20 小时。通过使用食物引诱剂的浓度-反应曲线估算 Bto 分离物的致死浓度（LC90），发现用有毒诱饵喂食的雌虫的总产卵量和卵胚胎活力显著降低（40%至 50%）。含食物引诱剂和 Bto （80×108 CFU. ml-1）的毒饵对 T. anastrephae 和 P. vindemmiae 成虫的死亡率没有显著影响（死亡率<20%）。Bti、Btk、Bc 和 Bto 等细菌分离物被认为是制备有毒诱饵的有前途的候选物，因为它们除了对 Z. indianus 成虫具有毒性作用外，对 T. anastrephae 和 P. vindemmiae 成虫没有毒性。
