This species inhabits places where its host plants are common and this includes costal dune habitat.

[1] The male holotype specimen was collected by George Hudson in Wellington and is held at the Natural History Museum, London.

[1] Dugdale described the larva of this species as follows: Body colour pattern in black and yellowish or greenish brown, variegated.

Dorsal area longitudinally, darkly marbled, seta D1 on a small, and D2 on a large white patch, the D2 patch connected with a prominent pallid subdorsal line; zone between this and spiracle longitudinally marbled; spiracle on a dark patch, subspiracular line broadest behind, narrowest just in front of spiracle; subventral and ventral zones pallid, obscurely marbled; ventral line obscure to prominent.

Forewings moderately dilated, costa almost straight, apex obtuse, hindmargin crenulate, obliquely with two tolerably distinct series of white dots, preceded and followed by black marks, before first and beyond second lines; lines dark-margined, tolerably defined; orbicular and claviform hardly traceable; reniform indicated by whitish lateral margins; subterminal faintly paler, not dark-margined, waved : cilia grey.

[1] P. homoscia has a plain brown coloured forewing and older specimens can possibly be confused with Ichneutica moderata.

[1] This species inhabits places where its host plants are common and this includes costal dune habitat.