Izatha heroica

Izatha heroica Philpott, 1926

This species was first described by Alfred Philpott in 1926 using a female specimen taken at Flora River, Mount Arthur in January.[3][4] The holotype specimen is held at the New Zealand Arthropod Collection.[5] Later that year Charles E. Clarke, thinking he was describing a new species, discussed and named the species Izatha toreuma.[6] Clarke used a male specimen obtained from Arthurs Pass in January.[5] This specimen is held at the Auckland War Memorial Museum.[5] This name was synonymised by George Hudson in 1928.[7]

Philpott described the female of the species as follows:

♀. 32 mm. Head and thorax white. Palpi white, basal half of second segment externally black, also an obscure blackish ring near apex, terminal segment with a sprinkling of black scales forming an indefinite ring at tooth. Antennae fuscous mixed with white, basal segment paler. Abdomen ochreous-whitish, apical segment brown. Legs grey-whitish, tarsi banded with dark fuscous. Forewings elongate, broad, costa well arched, apex obtuse, termen rounded, oblique; white, densely irrorated with pale fuscous; seven blackish spots on costa, first at base, second at ​¹⁄₄, third at ​¹⁄₂, seventh at apex, and remaining three at equal distances between third and seventh; a blackish spot in disc obliquely beyond second costal, and a linear blackish mark on fold beneath this; three blackish spots forming a triangle in disc at about middle, the most apical obliquely beyond third costal; a less clearly defined spot towards apex; a series of blackish spots on termen: fringes white. Hindwings grey-whitish with an undefined dark discal spot: fringes grey-whitish. A very distinct form, larger and without the dark fasciae of the other white species.[3]

The wingspan is 23–29 mm for males and 27–32 mm for females. Adults have been recorded in January, February and early March.[5] This species can be distinguished from similar species by its larger size, its greyish coloured forewing and the absence of a conical process on the top of the head.[8]

I. heroica is endemic to New Zealand and can only be found in the South Island.[5] Although the species prefers the west side of the Island it has been collected in Nelson, Marlborough, Marlborough Sounds, Westland, Fiordland, North Canterbury, Buller, Otago Lakes, Central Otago, and Southland.[5]

This species is attracted to light.[5]

Beech forest habitat of the moth

This species has been found in wetter forests of the western South Island including Nothofagus forest.[5] Larvae have been reared from erect dead Leptospermum.[9] The host may have been Kunzea ericoides or Leptospermum scoparium, since both were placed in the genus Leptospermum at this time.[9] This rearing record has led to the hypothesis that the species is not dependent on beech forest for its survival.[5]