Occurrence of a Pupal Melanization Reducing Factor in Different Insects

A pupal melanization reducing factor (PM R F) con­ trols incorporation of pigm ents into the cuticle of pupae of the nymphalid butterfly, Inachis io, to adapt their col­ oration to the background colors of their pupation sites. In the present paper, we report on the presence of PM RF in the central nervous system (CN S) of further butterfly species which exhibit a pupal morphological color adaptation. Interestingly, two butterfly species which do not show such an adaptation, and even two moth species which pupate in cocoons also contained PM RF in their CNS. The ganglionic extracts of non-lepidopteran species did not show a PM RF activity. The oc­ currence of PM RF (or PM RF-like m olecules), therefore, may be restricted to the lepidopteran order.