Integrative taxonomy reveals cryptic diversity in North American Lasius ants, and an overlooked introduced species - Schär, Sämi (Institut de Biologia Evolutiva (UPF-CSIC) (Barcelona)) ; Talavera, Gerard (Institut Botànic de Barcelona) ; Rana, Jignasha (The George Washington University. Department of Biological Sciences) ; Espadaler, Xavier (Centre de Recerca Ecològica i d'Aplicacions Forestals) ; Cover, Stefan P. (Harvard University. Museum of Comparative Zoology) ; Shattuck, Steven O. (Harvard University. Museum of Comparative Zoology) ; Vila Ujaldón, Roger (Institut de Biologia Evolutiva (UPF-CSIC) (Barcelona)) ; Universitat Autònoma de Barcelona. Departament de Biologia Animal, de Biologia Vegetal i d'Ecologia