Scolopterus tetracanthus

Scolopterus tetracanthus, more commonly known as the four-spined weevil, is a beetle of the genus Scolopterus. First described by A. White in 1846, it is endemic to New Zealand.

Scolopterus tetracanthus
Scolopterus tetracanthus seen in Titirangi, Auckland, New Zealand
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Curculionidae
Genus: Scolopterus
Species:
S. tetracanthus
Binomial name
Scolopterus tetracanthus
White, 1846
S.tetracanthus observations, range map from Global Biodiversity Information Facility (GBIF) (1920–2024)

Taxonomy

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The species was described by Scottish zoologist Adam White in 1846, who based his description on specimens collected during the Ross expedition.[1] Thomas Broun designated S. tetracanthus as the type species of the genus Scolopterus in 1880.[2]

Physical characteristics

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S. tetracanthus observed in Dunedin

White's original text (the type description) reads as follows:

Head and thorax deep black; elytra greenish bronze, the spines purplish black, the femora purplish black, the remainder of the legs purplish ferruginous; head and thorax quite smooth; elytra very deeply punctured in lines, the shoulders produced into a thick angular spine directed outwards and very slightly upwards; each elytron about the middle with a strong spine near the suture directed somewhat backwards and tufted with hair at the end; the intermediate femora with a compressed spine below near the end.[1]

The four-spined weevil is highly distinct in appearance, with knobs and spines common on its physical form.[3][4] The shoulder of each elytron forms into an acute cone,[5] with a sharp spine at the summit of the hind slope,[6] distinguishing them from their less pointed and spiny cousin, Scolopterus penicillatus.

It is about 7–8 mm (0.28–0.31 in) long, usually shiny black with bronze or red reflections.[6] Metallic and bright colours are not common in this family.[3]

It has a smooth head and thorax, with elytra very deeply punctured in lines.[2] One major feature of an elytra in Coleoptera is the striae,[7] and in the case of Scoplopterus tetracanthus, they have very deeply prominent punctures.[2]

Individuals within the genus of Scolopterus tend to have large, longitudinally oval eyes that are not convexed, and sit on the upper surface either side of their narrow head.[8]

Behaviour

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The four-spined weevil is a pollinator of an endemic tree to New Zealand, Schefflera digitata, of the family Araliacaea, known also as patē, seven-finger, or umbrella tree.[9]

Distribution and habitat

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Distribution

They are naturally uncommon,[10] but distributed in forest throughout North Island of New Zealand, with very few observations recorded in South Island[6]

Habitat

Four-spined weevils are known to breed in dead and rotting timber.[11] The larvae of Scoplopterus require dead wood to eat and grow.[12] Adults can be found in spring, summer and autumn.[13]

References

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  1. ^ a b White, A. (1846). "Insects of New Zealand". The zoology of the voyage of the H.M.S. Erebus & Terror. Wikidata Q130238153.  This article incorporates text from this source, which is in the public domain.
  2. ^ a b c Broun, Thomas (1880), Manual of the New Zealand Coleoptera, Wellington, doi:10.5962/BHL.TITLE.9559, LCCN agr04003496, OCLC 4526177, Wikidata Q51501870{{citation}}: CS1 maint: location missing publisher (link)
  3. ^ a b Walker, J.J. (1920). The president's address. - The fringes of butterfly life. Transactions of the Entomological Society of London. pp. 1919: XCI-CXIII.
  4. ^ Walker, J.J. (1904). Antipodean field notes. 2 - A year's insect hunting in New Zealand (40:68-77 ed.). Entomologist's monthly magazine.
  5. ^ Cawthra, E.M. (1966). "A redefinition of the subfamily Eugnominae to include the Meriphinae". Transactions of the Royal Society of New Zealand: Zoology. 7 (12): 171–178.
  6. ^ a b c Hudson, G.V (1934). New Zealand beetles and their larvae: an elementary introduction to the study of our native Coleoptera. FERGUSON & OSBORN LTD, WELLINGTON: 236 PP.
  7. ^ Hulcr, Jiri; Atkinson, Thomas H.; Cognato, Anthony I.; Jordal, Bjarte H.; McKenna, Duane D. (2015-01-01), Vega, Fernando E.; Hofstetter, Richard W. (eds.), "Chapter 2 - Morphology, Taxonomy, and Phylogenetics of Bark Beetles", Bark Beetles, San Diego: Academic Press, pp. 41–84, doi:10.1016/b978-0-12-417156-5.00002-2, ISBN 978-0-12-417156-5, retrieved 2024-08-30
  8. ^ Broun, T. (1893). "Manual of the New Zealand Coleoptera". Government Printer, Wellington. 5, 6 & 7 (V–XVII): 975–1504.
  9. ^ Heine, E.M. (1937). "Observations on the pollination of New Zealand flowering plants". Transactions and Proceedings of the Royal Society of New Zealand. 67: 133–148.
  10. ^ Moeed, Abdul; Meads, M. J. (1983). "Invertebrate Fauna of Four Tree Species in Orongorongo Valley, New Zealand, as Revealed by Trunk Traps". New Zealand Journal of Ecology. 6: 39–53. ISSN 0110-6465. JSTOR 24052727.
  11. ^ Anon (1957). Forest insect survey and life, Forest insect survey newsletter. Forest research institute, N.Z. pp. Forest Service: 6:1-32.
  12. ^ May, Brenda M. (1993). Larvae of Curculionoidea (Insecta: Coleoptera): a systematic overview. Fauna of New Zealand, Ko te Aitanga Pepeke o Aotearoa, Number / Nama 28 (PDF). Lincoln, Canterbury, New Zealand: Manaaki Whenua Press.
  13. ^ Moeed, Abdul; Meads, M. J. (1987). "Seasonality of arthropods caught in a Malaise trap in mixed lowland forest of the Orongorongo Valley, New Zealand". New Zealand Journal of Zoology. 14 (2): 197–208. doi:10.1080/03014223.1987.10422990. ISSN 0301-4223.