Meterana grandiosa

This species was first described and illustrated by Alfred Philpott in 1903 and was given the name Melanchra grandiosa.[1] Philpott used a female specimen he collected at West Plains in Southland in May.[3] George Hudson discussed and illustrated this species in his 1928 book The Butterflies and Moths of New Zealand.[4] In 1988 John S. Dugdale placed this species within the genus Meterana.[2] The hototype specimen is held at the New Zealand Arthropod Collection.[2]

Larvae are green in appearance with a broad white lateral stripe.[5] As they mature larvae turn a pinkish colour and can grow to be 3.3 cm in length.[5]

Philpott originally described the adult female of the species as follows:

♀︎ , 44 mm. Antennae and legs brownish-ochreous. Palpi brown, terminal joint ochreous. Face greyish. Thorax bright orange-brown, between patagia brownish-yellow ; slight anterior and strong double posterior crest. Abdomen dull-brownish, anal segment tipped with pale-yellow. Fore wings slightly sinuate on costa, apex subacute, termen crenulate, purplish-brown, base suffused with ochreous. An indistinct pale irregular line near base ; a small elongate yellow spot above middle at about 1⁄5 ; an ochreous patch below middle from base to 1⁄5 ; below this a broad elbowed black line to 1⁄4 ; dorsum broadly suffused with pale-ochreous ; an irregular V-sbaped pale purplish-brown line from near costa at about 1⁄4;, shortly bent towards base, thence obliquely to near dorsum at 1⁄2, again slanting upwards to reniform ; space within V-shaped line much darker. Near centre of wing, above middle, a large bell-shaped ochreous blotch, the base towards costa. Eeniform faintly outlined in pale purplish-grey. A sharply defined oblique line from costa near apex to dorsum at 2⁄3 , dentate near apex and broadly projecting below middle ; beyond this line the colour is ochreous-brownish densely irrorated with dark- brown. A waved subterminal line. Cilia brownish-ochreous on termen, pale-ochreous on dorsum. Hind wings dull brownish ; cilia brown, greyish towards tornus.[3]

This species is endemic to New Zealand.[6] M. grandiosa has occurred in Wairarapa, Central Otago, Otago Lakes, Dunedin and Southland zones.[7][5] However this species is now locally extinct in its type locality of West Plains and has not been collected in Dunedin since the 1960s.[7]

Larvae hide underneath the bark of their host plants during the day which makes them difficult to detect.[7] Larvae pupate between November and December and the adult moth emerges during the autumn months of mid April to early June.[7]

Host Olearia odorata

The plant host species for the larvae of M. grandiosa are small-leaved Olearia species.[7][5] These include O. hectorii and O. odorata.[7]

This moth is classified under the New Zealand Threat Classification system as being "At Risk, Relict".[8] One of the reasons for this classification is that the habitat of this species is under threat from land development.[7] The elimination of the host plants of this species has resulted in their extinction from sites in New Zealand.[5]