Naturally occurring April activity is not impossible here in NC, esp. in the eastern half of the state and may only be a bit early for central NC depending on year to year fluctuations. I modified the comment to better reflect that (several cocoons were brought indoors to initiate early eclosions to sync. with the earliest natural eclosions - these are not "reared indoors").

I'll review all my ecl. dates on posted images; I know some dates are too early or do not reflect natural occurrence, hence are omitted. In particular are the non-NC specimens, incl. Hyalophora species, populations &/or Hybrids which had to be maintained indoors within a USDA quarantine facility for the entire duration of their lives, incl. diapause.

Rearing Hyalophora species (egg to adult) indoors is not necessarily a "cause" for early eclosion as seen in many other Lep's. Most members of this Genus are genetically univoltine and eclosion times/dates usually reflect the conditions under which the pupae are maintained - in fact, sporadic eclosion may occur early or even fail to occur when expected if the pupae are not "given a cold spell" to initiate & subsequently break diapause - when subjected to warming!

To address your concern for the ecl. dates on my posted NC material - Most of the cecropia colonies we maintain have been derived from local stocks and kept under conditions favoring synchronized eclosion with wild pop's. We deliberately do this so that eclosing adults are reproductively synchronized with local stocks in the wild. YES, we do bring some cocoons indoors or remove them from coolers sometime between mid to late Feb-March to initiate early eclosion (aiming for April). However, due to seasonal fluctuations in this area cecropia activity varies; we use virgin females to test for male activity in the wild (starting late April-early June) so as not to miss wild pairings to maintain diversity within our cultures.

Natural April eclosion even seems to occur far to the north in Ontario, Canada.