Helastia angusta

Helastia angusta
Male

Relict (NZ TCS)
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Geometridae
Genus: Helastia
Species:
H. angusta
Binomial name
Helastia angusta
Craw, 1987[1]

Helastia angusta is a moth of the family Geometridae. This species is endemic to New Zealand and has been observed in the Mackenzie and Otago Lakes districts of the South Island. The preferred habitat of this species is montane areas. Adults have been observed on the wing from October until December. As at 2000, the larval host species is unknown. It is classified as "At Risk, Relict'" by the Department of Conservation.

Taxonomy

This species was first described by Robin C. Craw in 1987 using specimens collected by John S. Dugdale at Moke Lake and a specimen collected at the Humboltd Mountains.[2][3] It has been stated that the separation of this species from its close relative H. expolita is controversial.[4] The male holotype specimen, collected at Moke Lake, is held at the New Zealand Arthropod Collection.[2]

Description

Helastia angust male holotype

Craw described the species as follows:

Medium sized (r.f.l. 13.5-14.1 mm) narrowly falcate forewing. Upperside forewing coloured whitish purplish brown with darker transverse basal, antemedial and postmedial lines; oblique purplish brown apical streak. Postmedial line with distinct double toothed median projection; basal line evenly curved, no angular projection. Male antennae ciliated.[3]

Although similar in appearance to its relative H. expolita, H.angusta can be distinguished by its narrower forewing and the more rounded appearance of its underside basal line.[3] The entomologist Graham White has stated that the size of the discal dot in H. angusta is smaller than that of H. expolita.[4]

Distribution

This species is endemic to New Zealand.[1][5] It occurs in the Otago Lakes and Mackenzie areas.[6]

Habitat and host species

The preferred habitat of H. angusta is montane areas.[4] The host species for the larvae of H. angusta is unknown but it has been hypothesised it may be a shrub species.[6] Moth species closely related to H. angusta have larvae that feed Helichrysum lanceolatum.[4]

Behaviour

Adults have been observed on the wing from October until December.[7] This species is nocturnal and are attracted to light.[3][8]

Conservation status

This moth is classified under the New Zealand Threat Classification system as being "At Risk, Relict".[9]

References

Wikimedia Commons has media related to Helastia angusta.
  1. ^ a b "Helastia angusta Craw, 1987". www.nzor.org.nz. Landcare Research New Zealand Ltd. Retrieved 2018-05-16.
  2. ^ a b Dugdale, J. S. (1988). "Lepidoptera - annotated catalogue, and keys to family-group taxa" (PDF). Fauna of New Zealand. 14: 68. Archived from the original (PDF) on 27 January 2019. Retrieved 15 May 2018.
  3. ^ a b c d R. C. Craw (April 1987). "Revision of the genus Helastia sensu stricto with description of a new genus (Lepidoptera: Geometridae: Larentiinae)". New Zealand Journal of Zoology. 14 (2): 269–293. doi:10.1080/03014223.1987.10422997. ISSN 0301-4223. Wikidata Q54670161.
  4. ^ a b c d Pawson, S.M.; Emberson, R.M. (2000). "The conservation status of invertebrates in Canterbury" (PDF). Conservation Advisory Science Notes. 320: 1–64.
  5. ^ Gordon, Dennis P., ed. (2010). New Zealand inventory of biodiversity: Kingdom animalia: chaetognatha, ecdysozoa, ichnofossils. Vol. 2. p. 459. ISBN 978-1-877257-93-3. OCLC 973607714. OL 25288394M. Wikidata Q45922947.
  6. ^ a b Patrick, Brian; Dugdale, John S. (2000). Conservation status of the New Zealand lepidoptera (PDF). Wellington, N.Z.: Department of Conservation, New Zealand. p. 24. ISBN 0478218672. OCLC 154670803.
  7. ^ "Helastia angusta Craw, 1987". www.gbif.org. 2023. Retrieved 2023-04-27.
  8. ^ Carey Knox (2024). Butterflies & Moths of Aotearoa New Zealand. John Beaufoy Publishing. p. 56. ISBN 978-1-913679-66-8. Wikidata Q130640046.
  9. ^ Hoare, R.J.B.; Dugdale, J.S.; Edwards, E.D.; Gibbs, G.W.; Patrick, B.H.; Hitchmough, R.A.; Rolfe, J.R. (2017). Conservation status of New Zealand butterflies and moths (Lepidoptera), 2015 (PDF). Wellington, New Zealand: New Zealand Department of Conservation. p. 7. ISBN 9781988514383.