Silva Gerson A, Picanço Marcelo C, Ferreira Lino R, Ferreira Dalton O, Farias Elizeu S, Souza Thadeu C, Rodrigues-Silva Nilson, Pereira Eliseu José G
Laboratory of Entomology and Plant Pathology, Universidade Estadual Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, Brazil.
Department of Entomology, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil.
J Econ Entomol. 2018 Feb 9;111(1):218-226. doi: 10.1093/jee/tox346.
In this study, we constructed crop life tables for Bacillus thuringiensis Berliner (Bt) Cry1Ab and non-Bt corn hybrids, in which yield-loss factors and abundance of predaceous arthropods were recorded during 2 yr at two locations. Corn kernel/grain was the yield component that had the heaviest losses and that determined the overall yield loss in the corn hybrids across years and locations. Yield losses in both corn hybrids were primarily caused by kernel-destroying insects. Helicoverpa zea (Boddie) and Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) were the key loss factors at one location, while at the other, the key loss factor was the silk fly larvae, Euxesta spp. (Diptera: Ulidiidae). Although the realized yield of corn grains was not different (P > 0.05) between Cry1Ab and non-Bt corn hybrids, the Bt corn hybrid reduced (P < 0.05) the damage by H. zea and S. frugiperda in three of the four field trials, particularly at the location where Lepidoptera were the key loss factors. As expected, no reduction in the abundance of predaceous arthropods was observed in Cry1Ab corn fields. Various species of natural enemies were recorded, particularly the earwig Doru luteipes (Scudder) (Dermaptera: Forficulidae), which was the most abundant and frequent predaceous insect. These results indicate that integration of pest management practices should be pursued to effectively minimize losses by kernel-destroying insects during corn reproductive stages when growing non-Bt or certain low-dose Bt corn cultivars for fall armyworm and corn earworm, such as those producing Cry1Ab or other Cry toxins.
在本研究中，我们构建了苏云金芽孢杆菌（Bt）Cry1Ab玉米杂交种和非Bt玉米杂交种的作物生命表，在两年时间里于两个地点记录了产量损失因素和捕食性节肢动物的数量。玉米粒/谷物是损失最严重的产量构成要素，它决定了不同年份和地点玉米杂交种的总体产量损失。两个玉米杂交种的产量损失主要由破坏籽粒的昆虫造成。在一个地点，棉铃虫（Helicoverpa zea (Boddie)）和草地贪夜蛾（Spodoptera frugiperda (Smith)，鳞翅目：夜蛾科）是关键损失因素，而在另一个地点，关键损失因素是麦蛾幼虫Euxesta spp.（双翅目：实蝇科）。尽管Cry1Ab玉米杂交种和非Bt玉米杂交种的玉米粒实际产量没有差异（P>0.05），但在四项田间试验中的三项试验里，Bt玉米杂交种减少了（P<0.05）棉铃虫和草地贪夜蛾造成的损害，特别是在鳞翅目昆虫为关键损失因素的地点。正如预期的那样，在Cry1Ab玉米田中未观察到捕食性节肢动物数量的减少。记录了各种天敌物种，特别是蠼螋Doru luteipes (Scudder)（革翅目：球螋科），它是最常见且数量最多的捕食性昆虫。这些结果表明，在种植非Bt或某些低剂量Bt玉米品种（如产生Cry1Ab或其他Cry毒素的品种）防治秋粘虫和玉米穗虫时，应采用综合害虫管理措施，以有效减少玉米生殖阶段破坏籽粒的昆虫造成的损失。
