''Theoxena'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

moth genus in the family

Geometridae The geometer moths are moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyleti ...

erected by

Edward Meyrick Edward Meyrick (25 November 1854 – 31 March 1938) was an English schoolmaster and amateur entomologist. He was an expert on microlepidoptera and some consider him one of the founders of modern microlepidoptera systematics. Life and work Ed ...

in 1883. The only described species in this genus, ''Theoxena scissaria'', was first described by

Achille Guenée Achille Guenée (sometimes M.A. Guenée; 1 January 1809 – 30 December 1880) was a French lawyer and entomologist. Biography Achille Guenée was born in Chartres and died in Châteaudun. He was educated in Chartres, where he showed a very ear ...

in 1868. This species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

and is now only found in the Makenzie Country and Central Otago regions of the

South Island The South Island ( , 'the waters of Pounamu, Greenstone') is the largest of the three major islands of New Zealand by surface area, the others being the smaller but more populous North Island and Stewart Island. It is bordered to the north by ...

. There are two generations per year with the adult moths being observed on the wing most commonly in the months of May to July. As at 2024, only the male of this species has been observed with the female being unknown. It has been hypothesised that the female may be flightless. The species is said to have an affinity for ''

Poa cita ''Poa cita'', commonly known as the silver tussock, or wī, which is also a Māori name, or by the Māori name , is a grass of the family Poaceae that is endemic to New Zealand. ''Poa cita'' was described and named by Elizabeth Edgar in 1986, ha ...

'' as well as for species in the genus ''

Carmichaelia ''Carmichaelia'' (New Zealand brooms) is a genus of 24 plant species belonging to Fabaceae, the legume family. All but one species are native to New Zealand; the exception, '' Carmichaelia exsul'', is native to Lord Howe Island and presumably dis ...

.'' Although ''T. scissaria'' has been collected during the day, it is also attracted to light. This species has been classified as ''nationally vulnerable'' by the

Department of Conservation Department may refer to: * Departmentalization, division of a larger organization into parts with specific responsibility Government and military *Department (administrative division), a geographical and administrative division within a country, ...

. It is likely

locally extinct Local extinction, also extirpation, is the termination of a species (or other taxon) in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a chan ...

on the

Canterbury Plains The Canterbury Plains () are an area in New Zealand centred in the Mid Canterbury, to the south of the city of Christchurch in the Canterbury region. Their northern extremes are at the foot of the Hundalee Hills in the Hurunui District, and ...

Taxonomy

The genus ''Theoxena'' was described by Edward Meyrick in 1883. The species ''Theoxena scissaria'' was first described by Guenée in 1868 from a specimen obtained in

Canterbury Canterbury (, ) is a City status in the United Kingdom, city and UNESCO World Heritage Site, in the county of Kent, England; it was a county borough until 1974. It lies on the River Stour, Kent, River Stour. The city has a mild oceanic climat ...

Richard William Fereday Richard William Fereday ( 1820–30 August 1899) was a New Zealand lawyer, entomologist and artist. Early life He was born in Ettingshall, Staffordshire, England in 1820 to John Turton Fereday, an ironmaster and his wife, Ann Cecilia Heming ...

and named ''Panagra scissaria''. In 1883

placed the species into the newly created genus ''Theoxena''. In 1898 and in 1928

George Vernon Hudson George Vernon Hudson FRSNZ (20 April 1867 – 5 April 1946) was a British-born New Zealand entomologist credited with proposing the modern daylight saving time. He was awarded the Hector Memorial Medal in 1923. Biography Born in London, E ...

also described and illustrated ''Theoxena scissaria''. The

lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to anchor or centralizes ...

specimen, collected in Christchurch, is held at the

Natural History Museum, London The Natural History Museum in London is a museum that exhibits a vast range of specimens from various segments of natural history. It is one of three major museums on Exhibition Road in South Kensington, the others being the Science Museum (Lo ...

Description

Meyrick described the species as follows: As at 2024 the female of this species is unknown and it has been hypothesised that they are flightless.

Distribution

This species is

. Its range is in North Canterbury, Mid Canterbury, South Canterbury, Mackenzie, Central Otago and Otago Lakes. Other than the type locality, specimens have been collected near the foot of

Mount Hutt Mount Hutt () rises to the west of the Canterbury Plains in the South Island of New Zealand, above the braided upper reaches of the Rakaia River, and 80 kilometres west of Christchurch. Its summit is 2190 metres above sea level. The New Zeala ...

, the Winchmore Irrigation Research Station near Ashburton, at the lower slopes of Mount Ida in

Otago Otago (, ; ) is a regions of New Zealand, region of New Zealand located in the southern half of the South Island and administered by the Otago Regional Council. It has an area of approximately , making it the country's second largest local go ...

, Horseshoe Slip on

Mount Grey Mount Grey (officially Mount Grey / Maukatere) is a mountain west of Amberley in New Zealand. It is named after Sir George Grey who was governor of New Zealand when English surveyors climbed it in 1849. In Te Reo Māori, the mountain is cal ...

, and

Ashley Gorge The Ashley Gorge is a river gorge of the Ashley River / Rakahuri in Canterbury, New Zealand. The river is bridged at the mouth of the gorge by the Inland Scenic Route, formerly designated State Highway 72. A popular picnic ground and camping area ...

. It is now possibly extinct on the Canterbury Plains.

Life cycle and behaviour

The life history of ''T. scissaria'' is still uncertain. Adults have been collected in late winter at the foot of Mount Ida, though none were collected there after August. This species has also been recorded as being on the wing in June, December and January. It is most commonly seen between the months of May and July. A second generation emerges during the summer months. Although ''T. scissaria'' has been collected during the day, it is attracted to light.

Habitat

This species frequents plains.

Host species

The host species of ''T. scissaria'' is as yet unknown. However, this species has been associated with the tussock grass species ''

''. It has been hypothesised that the host species for ''T. scissaria'' larvae may be species in the genus ''

''.

Conservation status

This moth is classified under the

New Zealand Threat Classification system The New Zealand Threat Classification System is used by the Department of Conservation to assess conservation priorities of species in New Zealand. The system was developed because the IUCN Red List, a similar conservation status system, had s ...

as being ''nationally vulnerable''.

References

{{Taxonbar , from1=Q13541584 , from2=Q18522292 Geometridae Moths described in 1868 Moths of New Zealand Endemic fauna of New Zealand Taxa named by Achille Guenée Endangered biota of New Zealand Endemic moths of New Zealand