Interspecific effects of the pupal melanization reducing factor on pupal colouration in different lepidopteran families

The lepidopteran pupae of Aglais urticae L., Inachis io L. (Nymphalidae), and Pieris brassicae L. (Pieridae) show a morphological colour adaptation. Their melanization is controlled by a pupal melanization reducing factor, which gradually inhibits cuticular melanization. Extracts from head-prothorax fragments of A. urticae as well as of Galleria mellonella L. (Pyralidae), a species without a pupal colour adaptation, reduce melanization in pupae of I. io in a dose-dependent way. However, extracts of P. brassicae injected into I. io show a weaker melanization reducing factor activity than those of the other two species. Pupal melanization reducing factor extracts from head-prothorax fragments of Inachis is show dose-dependent melanization reducing effects on the pupal colouration of all three species, A. urticae, I. io, and P. brassicae.