Could you please point out the differences between this and H. melanotypa https://canberra.naturemapr.org/sightings/4456941? I don't know what to look for in moths (or lots of other things either).
H. melanotypa, among the markings on each forewing, has an extra dark stripe near the base, and a dark triangle near the middle of the hind-margin. H. argyroleuca either has these two extra markings absent or paler brown.
It would be helpful to add the photos of any reared adults to the CNM sightings of the larva or larval cases from which they each came. This would simplify discerning any differences between the larval cases of the different species.