The use of genetically modified varieties tolerant to herbicides (HT varieties) and resistant to insects (Bt varieties) in combination with application of a broad-spectrum herbicide such as glyphosate could be an effective option for the simultaneous control of weeds and pests in maize. Nevertheless, the possible impact of these tools on nontarget arthropods still needs to be evaluated. In a field study in central Spain, potential changes in populations of canopy-dwelling arthropods in Bt maize under different weed management options, including glyphosate application, were investigated. Canopy-dwelling arthropods were sampled by visual inspection and yellow sticky traps. The Bt variety had no effect on any group of studied arthropods, except for the expected case of corn borers—the target pests of Bt maize. Regarding the effects of herbicide regimes, the only observed difference was a lower abundance of Cicadellidae and Mymaridae on yellow sticky traps in plots not treated with pre-emergence herbicides. This effect was especially pronounced in a treatment involving two glyphosate applications. The decrease in Cicadellidae and Mymaridae populations was associated with a higher density of weeds in plots, which may have hindered colonization of the crop by leafhoppers. These differences, however, were only significant in the last year of the study. The low likelihood of the use of glyphosate- and herbicide-tolerant varieties for weed control triggering important effects on the nontarget arthropod fauna of the maize canopy is discussed.

中文翻译：

---

常规和转基因抗虫玉米中不同杂草管理方案（包括草甘膦）下冠层节肢动物的动态


使用耐除草剂（HT品种）和抗虫（ Bt品种）的转基因品种并结合使用草甘膦等广谱除草剂可能是同时控制玉米杂草和害虫的有效选择。然而，这些工具对非目标节肢动物可能产生的影响仍需要评估。在西班牙中部的一项实地研究中，研究了不同杂草管理方案（包括施用草甘膦）下Bt玉米冠层节肢动物种群的潜在变化。通过目视检查和黄色粘虫捕捉器对栖息在树冠上的节肢动物进行取样。除预计的玉米螟（ Bt玉米的目标害虫）外， Bt品种对所研究的任何节肢动物群均没有影响。关于除草剂方案的影响，观察到的唯一差异是未使用芽前除草剂处理的地块中黄色粘虫诱捕器上蝉科和蝉科的丰度较低。这种效果在涉及两次草甘膦施用的治疗中尤其明显。蝉科和蝇科种群数量的减少与地块中杂草密度较高有关，这可能阻碍了叶蝉在作物上的定植。然而，这些差异仅在研究的最后一年才显着。讨论了使用耐草甘膦和除草剂品种进行杂草控制对玉米冠层非目标节肢动物群产生重要影响的可能性很小。