Field cultivation of Genetically Modified (GM) Bt-plants has a potential environmental risk toward non-target Lepidoptera (NTLs) larvae through the consumption of Bt-maize pollen. The Bt-maize Cry protein targeting Lepidoptera species detrimental to the crop is also expressed in pollen which is dispersed by wind and can thus reach habitats of NTLs. To better assess the current ecological risk of Bt-maize at landscape scales, we developed a spatially-explicit exposure-hazard model considering (i) the dynamics of pollen dispersal obtained by convolving GM plants emission with a dispersal kernel and (ii) a toxicokinetic-toxicodynamic (TKTD) model accounting for the impact of toxin ingestion on individual lethal effects. We simulated the model using real landscape observations in Catalonia (Spain): GM-maize locations, flowering dates, rainfall time series and larvae emergence date of the European peacock butterfly Aglais io. While in average, the additional mortality appears to be negligible, we show significant additional mortality at sub-population level, with for instance a mortality higher than 40% within the 10m for the 10% most Bt-sensitive individuals. Also, using Pareto optimality we capture the best trade-off between isolation distance and additional mortality: up to 50 m are required to significantly buffer Bt-pollen impact on NTLs survival at the individual level. Our study clears up the narrow line between diverging conclusions: those claiming no risk by only looking at the average regional effect of Bt on NTLs survival and those pointing out a significant threaten when considering the variability of individuals mortality.

通过食用Bt玉米花粉，转基因Bt植物的田间种植对非目标鳞翅目（NTLs）幼虫具有潜在的环境风险。靶向有害于鳞翅目的鳞翅目物种的Bt玉米Cry蛋白也在花粉中表达，该花粉通过风散布并且因此可以到达NTL的栖息地。为了更好地评估当前Bt玉米在景观尺度上的生态风险，我们开发了一种空间显性暴露-危害模型，其中考虑了（i）通过将转基因植物的排放物与分散核混合而获得的花粉分散动力学，以及（ii）毒性动力学-毒物动力学（TKTD）模型说明了毒素摄入对个体致死作用的影响。我们使用加泰罗尼亚（西班牙）的真实景观观察结果模拟了该模型：转基因玉米位置，开花日期，Aglais io。虽然平均而言，额外死亡率似乎可以忽略不计，但我们在亚人群水平上显示出显着的额外死亡率，例如，对Bt敏感性最高的10％人群在10m内死亡率高于40％。此外，使用帕累托最优性，我们可以在隔离距离和额外死亡率之间取得最佳平衡：需要最大50 m的距离才能显着缓冲Bt花粉对个体层面NTL存活的影响。我们的研究清除了不同结论之间的狭窄界限：仅通过观察Bt对NTL生存的平均区域影响来声称没有风险的人，以及在考虑个人死亡率的变异性时指出严重威胁的人。