Ichneutica blenheimensis

Observation of live Ichneutica blenheimensis

This species was described by Richard William Fereday in 1883 using a female specimen collected by William Skellon in Meanee near Napier.[3][4] Fereday originally named the species Leucania blenheimensis.[4] In 1887 Edward Meyrick described the male of the species.[5] George Hudson discussed and illustrated this species under this name in both his 1898 and 1928 publications.[6][7] In 1971 John S. Dugdale transferred all the New Zealand species in the genus Leucania to the genus Tmetolophota.[4][8] The lectotype specimen is held at the Canterbury Museum.[4] In 2019 Robert Hoare undertook a major review of New Zealand Noctuidae.[2] During this review the genus Ichneutica was greatly expanded and the genus Tmetolophota was subsumed into that genus as a synonym.[2] As a result of this review, this species is now known as Ichneutica blenheimensis.[2]

A. V. Chappell described the egg as follows:

Pale cream ; light brownish with brown ring and central spot on the top ; dark brown ; pale blackish ; finely sculptured.[9]

A. V. Chappell also described the larva as follows:

Pale dusky yellow ; transparent ; numerous stout black hairs rising singly from black spots ; head large, pale amber speckled with black.[9]

Hudson described the adults of this species as follows:

The expansion of the wings is about 1+1⁄2 inches. The fore-wings are cream-coloured with the veins darker ; there are three faint black dots at about one-third, a curved series of black dots near the termen, the termen itself being strongly shaded with dark greyish-brown; the cilia are dark greyish- brown. The hind-wings are grey, paler towards the base ; the cilia are also grey.[6]

The wingspan of the adult male is between 37 mm and the female wingspan is between 40 and 41 mm.[2] The blackish forewing fringes are diagnostic of this species.[2] Worn specimens of I. arotis can be confused with worn specimens of I. blenheimensis.[2] However I. arotis can be distinguished from I. blenheimensis as it has a scale-tuft on the thorax and dark longitudinal stripes on the tegula.[2]

This species is endemic to New Zealand.[10] It is found throughout the North, South and the Stewart Islands.[2] The range of this species covers the Hawkes Bay, Marlborough, Dunedin, Otago Lakes, Southland and the Stewart Island regions.[11] Along with the type locality of Meanee, specimens have also been collected at the Denniston plateau,[12] Blenheim,[3] Dunedin, Lake Wakatipu and Routeburn.[7]

This species is on the wing from November to March.[7] It has been collected via sugar traps and is attracted to light.[3][13]

The host plant for the larvae of this species is likely to be the golden sand sedge pīngao which is now absent from the moths type locality.[11] Chappell states very young larvae eat grass species but more developed larvae consumed Phormium tenax.[9] Based on collections this species appears to prefer drier eastern localities and is rarely collected in western North Island forested areas.[2] It does not appear to be frequently collected in dry inland tussock grassland habitats.[2]

This species has been classified as having the "At Risk, Naturally Uncommon" conservation status under the New Zealand Threat Classification System.[14]