If pattern elements, such as eyespots and perhaps bands,
are established by signals from discrete foci on the early
pupal epidermis, the location of those foci must have been
specified earlier, in the larval imaginal disc. There is little
experimental evidence, but specification of foci is likely to
occur in response to signals from the lacunae that will later
form the veins and margin of the pupal and, eventually, the
adult wing.(