Insects are highly involved in accidental introductions in non-native areas. Potential distribution modelling is routinely used to predict the dynamics of such range expansions, giving insights on which areas are climatically suitable for establishment. However, even in areas where climatic conditions are unsuitable, colonization may be still possible in sub-areas with particular, human activity-driven microclimates, such as cities. We used as a model species the Asian mud-dauber wasp Sceliphron curvatum (Hymenoptera: Sphecidae), which arrived in Europe 40 years ago, to show that cities may be used by alien species to enlarge their distribution into climatically non-optimal areas. By using an average consensus from six different models, we predicted that, based on climate, S. curvatum would find the highest suitability in most part of Mediterranean basin, which are characterized by high summer temperatures and reduced climatic oscillations. The species is indeed often observed in such areas, but also in Central Europe, where suitability is overall lower. At such latitudes, however, the wasp was more often found in cities (which have the highest suitability) than in peri-urban and rural areas, possibly according to the urban ‘heat island’ effect. In Southern Europe, where climate is overall more favourable for the species, suitability tended to be more similar in both urban and rural environments, and urban detections were indeed rarer. The inclusion of population density in the model improved the suitability of Northern areas in an expected urbanization-driven jeopardized pattern. Hence, S. curvatum would be able to colonize in the future at least some climatically unsuitable Northern areas, reaching up to 70° latitude, by using cities as the main sites for establishment.

昆虫高度参与了非本地区域的意外引入。通常使用势能分布建模来预测此类范围扩展的动态，从而洞悉哪些气候区域适合建立。但是，即使在气候条件不合适的地区，在诸如人类活动等特定小气候的子区域（例如城市）中，定植仍然是可能的。我们以40年前到达欧洲的亚洲泥d黄蜂Scuriphron curvatum（膜翅目：Sphecidae）为模型物种，来表明外来物种可能利用城市将其分布扩大到气候非最佳区域。通过使用来自六个不同模型的平均共识，我们预测基于气候的S. curvatum它将在地中海盆地的大部分地区找到最高的适用性，其特征是夏季高温和减少的气候波动。实际上，该物种确实经常在此类地区观察到，但在中欧总体适宜性较低的地区也是如此。然而，在这样的纬度上，黄蜂在城市（最适合的城市）中比在郊区和农村地区更常见，这可能是由于城市的“热岛”效应所致。在总体上气候更有利于该物种的南欧，在城市和农村环境中的适应性趋于趋于相似，而且城市检测的确很少。在模型中纳入人口密度以预期的城市化驱动的危险模式改善了北部地区的适用性。因此，S。curvatum 通过将城市作为建立的主要地点，将来将能够在至少一些气候不合适的北部地区定居，达到北纬70°。