The orange sulphur (Colias eurytheme) and the clouded sulphur (Colias philodice) are virtually impossible to tell apart. They may even interbreed. For purposes of monitoring and counting here in northern Illinois, we treat them as one 'species.'
The orange sulphur (Colias eurytheme) and the clouded sulphur (Colias philodice) are virtually impossible to tell apart. They may even interbreed. For purposes of monitoring and counting here in northern Illinois, we treat them as one 'species.' This butterfly was released unharmed.
The orange sulphur (Colias eurytheme) and the clouded sulphur (Colias philodice) are virtually impossible to tell apart. They may even interbreed. For purposes of monitoring and counting here in northern Illinois, we treat them as one 'species.'
