A method for the quantitative analysis of wing spots applied to two populations of Calopteryx splendens (Harris) (Zygoptera: Calopterygidae)

The coloured wing spot on a sample of males from 2 populations of C. splendens s.l. (Boutonne, France; Ourthe, Belgium) are analysed, using an iterative computation procedure on wing images transferred to a computer memory by a video transducer. The analysis reveals significant differences in apical wing spot extent and total wing spot area, but not in basal wing spot extent. Its sensitivity is such that it permits to identify immigrants, thus potential gene flow, to the native population. The new possibilities for analysis of the complex of C. splendens are briefly discussed.