Izatha attactella

Hudson described the larvae of this species as being about 7⁄8 in. long when fully grown. The head is dark brown and shiny while the body is white. The pupa is pale ochreous in colour with a brown tinge to the head and lower portion of the pupa. It is enclosed in an oval cocoon made from silk and pieces of chewed bark.

Walker described the adults of the species as follows:

Male. Hoary, minutely blackish-speckled, cinereous and shining beneath. Third joint of the palpi with three blackish bands. Fore wings with a black slightly dislocated line, which is darkest and most concise towards the base, and does not extend to the tip of the wing; marginal points blackish, elongated, extending also along the exterior part of the costa; some small transverse irregular brown dots in the disk. Hind wings pale cinereous, shining. Var. — Fore wings clouded with brown. Length of the body 6 — 8 lines; of the wings 16 — 20 lines. The wingspan 24.5–38 mm for males and 22–36 mm for females. I. attactella resembles I. voluptuosa but can be distinguished from the latter by having a narrow forewing, a paler hind wing, more obvious scale tufts and a longer dark basal streak. I. attactella is also on the wing earlier in the season in September to December with I. voluptuosa being present in the later months of November to February.

This species is endemic to New Zealand. I. attactella is widespread and present in both the North and South Islands but in the latter only as far as mid Canterbury. This species has been recorded in the following locations: Northland, Auckland, Coromandel, Waikato, Bay of Plenty, Taranaki, Taupo, Hawkes Bay, Rangitikei, Wellington, Marlborough Sounds, Nelson, Buller, Marlborough and mid Canterbury.

Pupation takes place under the bark in the above described oval silk and chewed wood cocoon. Adults are on wing from September to December. However, in the South Island occasional specimens appear in December and January. When reared in captivity in the North Island this species emerges from July onwards. This species does not come readily to light in large numbers.