Dasyuris partheniata is a species of moth in the family Geometridae. It was first described by Achille Guenée in 1868. D. partheniata is endemic to New Zealand and is found in the North and South Islands. This species inhabits open grass areas including tussock grassland as well as coastal cliffs. It can be found at altitudes ranging from sea level up to 1350 m. The adults of this species are day flying and are on the wing from October to March. Larvae are nocturnal and feed on species in the genus Aciphylla including Aciphylla subflabellata and Aciphylla squarrosa. As at 2015 this species is classified as "At Risk, Declining" by the Department of Conservation.
Taxonomy This species was first described by Achille Guenée in 1868 from a specimen collected by Richard William Fereday in Canterbury. Edward Meyrick also gave a description of this species. George Vernon Hudson discussed and illustrated the species in multiple publications including in 1898, in 1928 and in 1939. He stated that Fereday's specimens were collected at the foot of Mount Hutt. The holotype specimen is held at the Natural History Museum, London.
Description
The eggs of this species are yellowish-white in appearance, elliptical in shape and have hexagonal depressions on the surface.
Larvae are coloured pale yellow-brown on their dorsal side and a dull ocherous shade on their lateral side. They have 16 legs and are extremely thin. Hudson described the larva of D. partheniata as follows:
Hudson pointed out that there is considerable variation in depth of colouring of larvae specimens. In some specimens the subdorsal line continues to be ochreous on posterior segments; in others the dark brown lateral line is rather broad; the lateral line is also sometimes very pale yellow and some specimens are tinged grey green.
The pupa is approximately cm long and is initially coloured pale yellow but darkens to golden then dark brown.
Hudson described the adults of the species as follows:
Distribution D. partheniata is endemic to New Zealand. It occurs from the southern parts of the North Island southwards. This species has been observed at Waiouru, the Tararua Range including at Mount Holdsworth, Wellington, Mount Arthur, Mount Hutt, Arthur's Pass National Park, Homer, Mount Cook, Dunedin, Lake Wakatipu, and at the Hump Ridge. The species can occur from sea level up to approximately 1500m in altitude.
Behaviour The adults of this species are day flying moths and are on the wing during the months of October to March.
The larvae of D. partheniata have been collected in May and can be difficult to detect amongst the needle like leaves of its host. The larvae eat in long sections, often right through the blade, leaving the veins of the leaves untouched. They are nocturnal and when their safety is threatened drop to the centre of the plants they are feeding on. The larvae of this species have been observed, in the present of a Ichneumon wasp, gripping the blade of its food plant with its prolegs and beating it with its body, causing the blade to move from side to side.
Habitat The species occurs in open grassy areas up to altitudes of 1350 m. In Wellington the species prefers coastal cliffs and at Mount Hutt specimens have been collected in tussock grass.
Host species The larval host plants of this species are in the genus Aciphylla and include Aciphylla subflabellata and Aciphylla squarrosa.
Conservation status This moth is classified under the New Zealand Threat Classification system as being At Risk and Declining.
References
External links
Image of larvae