Interspecific interactions were studied in 3 localities, where there are C. splendens populations with 2 female forms. The homeochromic form, possibly more vulnerable to predation because of its conspicuousness, gains advantage over the heterochromic form because it offers a better reproductive isolation. In fact homeochromic females sexually attract heterospecific males less often than the other females do and so are probably less often involved in heterospecific matings. This is the result of their wing colouration, variable according to the congeneric species sympatric in the single sites, which mimics the wings of C. haemorrhoidalis males and which is very different from those of C. virgo females.