Pyrgotis pyramidias

P. pyramidias was first described by Edward Meyrick in 1901 from a specimen collected by Alfred Philpott in Invercargill.[2] George Hudson described and illustrated this species in his 1928 book The Butterflies and Moths of New Zealand.[3] The holotype specimen is held at the Natural History Museum, London.[4] The holotype represents P. pyramidias sensu stricto.[4][5]

Meyrick originally described the species as follows:

♂︎. 16 m.m. Head orange. Palpi ochreous mixed with dark fuscous. Thorax orange-ochreous. Forewings rather elongate-triangnlar, costa moderately arched, apex round-pointed, prominent, termen oblique, rather sharply concave on upper half, prominent in middle ; reddish-ochreous, sprinkled with dark crimson, suffusedly irrorated with whitish except towards base and dorsal spot ; a sharp white triangular dorsal spot before middle, reaching nearly half across wing, anterior side shortest, enclosing two dark reddish-fuscous dorsal dots : cilia reddish-ochreous, with dark reddish median line, basal half whitish-mixed. Hindwings whitish-grey, becoming whitish towards costa, greyer terminally ; cilia whitish, with grey basal line.[2]

The holotype specimen described above is typical of the species from the type locality in that it has a drab appearance and is smaller than the form of the species existing in silver beech forest.[4][6] The adults of this latter form are more brightly coloured and patterned.[4][6] Doubt has been expressed whether this larger, more colourful form is the same species as the smaller, more drab form of this moth.[4][6]

This species is endemic to New Zealand.[1][7] It is found from the Bay of Plenty to Southland.[6] The type locality is around Awarua Bog and Tiwai Point[4] and this is where the smaller, more drab form of the species lives.[6] This form has also been found at Whakarewarewa in Rotorua.[5] The more colourful and patterned form of this species is found in the above stated range where its host plant is present.[3]

This species is on the wing between October and February.[3]

Host plant Leucopogon fasciculatus

The host plant of the larvae of P. pyramidia in the type locality and the above-mentioned population in Rotorua is Leucopogon fasciculatus.[5] The larger, more colourful and patterned form of this species has larvae that feed on Lophozonia menziesii. This host plant is absent from Invercargill and its surrounding area.[6]

P. pyramidia s.s. has been classified as having the "At Risk, Naturally Uncommon" conservation status under the New Zealand Threat Classification System.[8]