A sampling area of Callisto coffeella and C. basistrigella in Europe. B close up of the distribution of C. coffeella (green circles) and C. basistrigella (white squares) in the Alps; two C. basistrigella specimens (red triangles) show evidence of introgression. On Figs 19A, 19B, the 35 barcoded specimens are shown with numbers (1-5). The red circle on Fig. 19B shows the contact zone where both species occur together (Leitnertal, Eastern Tyrol, Austria and Sappada, Italy). When several samples were investigated per locality, the samples with the same coordinates have been slightly shifted in order to visualize overlapping data points on Fig. 19B.