''Hadramphus tuberculatus'' (known as the Canterbury knobbled weevil, Spaniard weevil or Banks Peninsula speargrass weevil) is a rare

weevil Weevils are beetles belonging to the superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and herbivorous. Approximately 97,000 species of weevils are known. They belong to several families, ...

endemic Endemism is the state of a species being found 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 found else ...

Canterbury Canterbury (, ) is a cathedral city and UNESCO World Heritage Site, situated in the heart of the City of Canterbury local government district of Kent, England. It lies on the River Stour. The Archbishop of Canterbury is the primate of ...

in the South Island of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. It was thought to be extinct in 1922 but was rediscovered in 2004.

Description

''H. tuberculatus'' is a flightless weevil with a knobbed back. It reaches a length of and a width of . It has a dark brown body with greyish-brown scales. This species tends to survive at high altitudes, specifically 670 meters, within the department of conservation reserve, where Aciphylla, a type of plant species, is abundant (Marris et al., 2008). In addition, in a study done where the ecology and conservation status of the Hadramphus tuberculatus was measured, it was found that the population size decreased from 2009 through 2011 – with the estimated population sizes being 138, 90, and 76, respectively (Fountain et al., 2013).

Taxonomy

This species was first described by Francis Pascoe in 1877 using specimens collected in Canterbury and supplied by Charles Marcus Wakefield. ''Hadramphus tuberculatus'' are characterized within the genus of weevils. They belong to the Molytini tribe which consists of four other species: H. tuberculatus, H. spinipennis Broun, H. stilbocarpae Kuschel, and H. pittospori. The ''Hadramphus tuberculatus'' are the largest weevils in terms of size and their distiniction stems from having rounded tubercles on their backs. In comparison, all four species are on the risk in terms of conservation (Cruickshank et al., 2018).

Status

The knobbled weevil were apparently common over 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 in t ...

in the 1870s. Possible causes for its disappearance were the removal by farmers of speargrass (''Aciphylla''), its host plant, and the arrival of predatory European rats. It was last seen in 1922, and was considered extinct until it was rediscovered in late 2004 by research students of the University of Canterbury at Burkes Pass near

Lake Tekapo __NOTOC__ Lake Tekapo ( mi, Takapō) is the second-largest of three roughly parallel lakes running north–south along the northern edge of the Mackenzie Basin in the South Island of New Zealand (the others are Lake Pukaki and Lake Ohau). ...

, South Canterbury, New Zealand. It is now listed as nationally endangered by the

New Zealand Department of Conservation The Department of Conservation (DOC; Māori: ''Te Papa Atawhai'') is the public service department of New Zealand charged with the conservation of New Zealand's natural and historical heritage. An advisory body, the New Zealand Conservation Au ...

, and as critically endangered in the IUCN Red List. A detailed ecological study conducted by researchers at Lincoln University in 2009–2011 estimated the population size at Burkes Pass to be only 138 individuals in 2009, decreasing each year to 76 in 2011.

Gallery of images

File:Hadramphus tuberculatus with pollen from Aciphylla aurea flower on rostrum.jpg, ''Hadramphus tuberculatus'' with pollen from ''Aciphylla aurea'' flower on rostrum File:Hadramphus tuberculatus recaptured during mark recapture study at Burkes Pass Scenic Reserve.jpg, ''Hadramphus tuberculatus'' recaptured during mark recapture study at Burkes Pass Scenic Reserve File:Hadramphus tuberculatus.jpg File:Captive rearing study of Hadramphus tuberculatus on a young Aciphylla aurea in an enclosure.jpg, Captive rearing study of ''Hadramphus tuberculatus'' on a young ''Aciphylla aurea'' in an enclosure at Lincoln University File:Hadramphus tuberculatus on Aciphylla aurea plant.jpg, ''Hadramphus tuberculatus'' on ''Aciphylla aurea''.

References

External links

Description and Image, PDF

Image of a Museum specimen, PDF

Past distribution of large weevils (Coleoptera: Curculionidae) in the South Island, New Zealand, based on Holocene fossil remains

Discovery brings weevil back from the brink
* ''Hadramphus tuberculatus'' discussed on RNZ ''

Critter of the Week ''Critter of the Week'' is a weekly RNZ National programme about endangered and neglected native plants and animals of New Zealand. Beginning in 2015, ''Critter of the Week'' is an approximately 15-minute discussion between Nicola Toki of the ...

''
23 October 2015
{{Taxonbar, from=Q250098 Beetles of New Zealand Molytinae Beetles described in 1877 Endangered biota of New Zealand Endemic fauna of New Zealand Taxa named by Francis Polkinghorne Pascoe Endemic insects of New Zealand