Data from: Environmental risk assessment for the small tortoiseshell Aglais urticae and a stacked Bt-maize with combined resistances against Lepidoptera and Chrysomelidae in central European agrarian landscapes

The cultivation of Lepidoptera-resistant Bt-maize may affect non-target butterflies. We assessed the risk posed by event MON89034 x MON88017 (expressing Cry1A.105 and Cry2Ab2 against corn borers) to non-target Lepidoptera. Using the small tortoiseshell Aglais urticae, a butterfly species common in central Europe, as a test organism we (1) assessed the toxicity of Bt-maize pollen on butterfly larvae; (2) measured pollen deposition on leaves of the host plant Urtica dioica; (3) mapped the occurrence and distribution of host plants and larvae in two arable landscapes in Germany during maize anthesis; and (4) described the temporal occurrence of a one-year population of A. urticae. (1) Larvae fed 200 Bt-maize pollen grains/cm2 had a reduced feeding activity. Significant differences in developmental time existed at pollen densities of 300 Bt-maize pollen grains/cm2 and in survival at 400 grains/cm2. (2) The highest pollen amount found was 212 grains/cm2 at the field margin. Mean densities were much lower. (3) In one region over 50% of A. urticae nests were located within five metres of a maize field, while in the other all nests were found in more than 25 m distance to a maize field. (4) The percentage of larvae developing during maize anthesis was 19% in the study area. The amount of pollen from maize MON89034 x MON88017 found on host plants is unlikely to adversely affect a significant proportion of larvae of A. urticae. This paper concludes that the risk of event MON89034 x MON88017 to populations of this species is negligible.种植抗鳞翅目害虫Bt玉米（Bt-maize）可能会对非靶标蝴蝶类群产生影响。本研究针对MON89034 x MON88017事件（该事件表达Cry1A.105与Cry2Ab2蛋白，用于防治玉米螟）对非靶标鳞翅目昆虫的潜在风险开展评估。本研究以中欧常见的荨麻蛱蝶（Aglais urticae）作为受试生物，开展了四项实验：(1) 评估Bt玉米花粉对该蛱蝶幼虫的毒性；(2) 测定寄主植物荨麻（Urtica dioica）叶片表面的花粉沉积量；(3) 在玉米扬花期，于德国两处农田景观中，绘制寄主植物与幼虫的发生分布图谱；(4) 描述该荨麻蛱蝶一年发生种群的时间动态。(1) 取食密度为200粒/cm²的Bt玉米花粉的幼虫，其取食活性出现下降；当花粉密度达到300粒/cm²时，幼虫的发育时长存在显著差异，而在400粒/cm²密度下，幼虫存活率显著降低。(2) 检测到的最高花粉沉积量出现在田埂区域，为212粒/cm²，平均沉积密度则远低于该数值。(3) 在其中一处研究区域内，超过50%的荨麻蛱蝶巢穴位于距玉米田5米范围内；而另一处区域的所有巢穴均分布在距玉米田25米以上的区域。(4) 研究区域内，在玉米扬花期完成发育的幼虫占比为19%。本研究在寄主植物上检测到的MON89034 x MON88017玉米花粉沉积量，不太可能对荨麻蛱蝶的大量幼虫种群造成不利影响。综上，MON89034 x MON88017事件对该蛱蝶种群的风险可忽略不计。