Xanthorhoe bulbulata explained

Xanthorhoe bulbulata is a species of moth in the family Geometridae. It is endemic to New Zealand. It is classified as critically endangered by the Department of Conservation.

Taxonomy

X. bulbulata was first described by Achille Guenée in 1868.^{[1] [2]} In 1883 Edward Meyrick placed the species within the genus Larentia.^[3] In 1898 George Vernon Hudson assigned the species to the genus Xanthorhoe.^[4] L. B. Prout, in 1939, again placed this species within the genus Larentia.^[5] In 1971 J. S. Dugdale disagreed with the placement and included this species within the genus Helastia. However this was not agreed with by R. C. Craw and in 1987 he placed the species within the genus Xanthorhoe.^[6] In 1988 Dugdale agreed with Craw's placement. The female holotype specimen is found at the Natural History Museum, London.

Original description

Guenée described the species as follows:

Distribution and habitat

This species is endemic to New Zealand.^[7] Historically this moth was distributed throughout much of the South Island with records obtained from as far north as Awapiri in the Awatere valley down to Invercargill.^{[8] [9]} The moths could be found in "open, grassy places" from sea level to elevations of 660-930m. Records suggest that the moth was once "common" between September and March.^[10]

Species decline

Despite having been common in New Zealand up to the 1930s,^[11] since 1 January 1940 there have been only two recorded collections of X. bulbulata. These were a male found flying during the day in Queenstown in 1979 and a female caught in a light trap between February and March 1991 at the Eastern entrance to the Kawarau Gorge.^[12] Intensive sampling for this moth covering 285 sites between 1995 and 2000 returned no specimens. However it has been hypothesised that the species may still exist and that it could be rediscovered if an extensive search in the beginning months of its flight period were undertaken at low altitude areas of the South Island or at mountainous sites during the later summer months.

It is thought that the documented decline in this species is the result of ecological changes to habitats following European settlement.

Conservation status

This species has the "Nationally Critical" conservation status under the New Zealand Threat Classification System.^[13] This species is feared extinct.^[14]

Notes and References

1. Guenée. Achille. 1868. New species, &c., of heterocerous Lepidoptera from Canterbury, New Zealand collected by Mr R. W. Fereday.. The Entomologist's Monthly Magazine. en. 5. 94. 0013-8908. Biodiversity Heritage Library.
2. Dugdale. J. S.. Lepidoptera – annotated catalogue, and keys to family-group taxa. Fauna of New Zealand. 1988. 14. 190. 9 May 2018. 22 July 2019. https://web.archive.org/web/20190722101744/https://www.landcareresearch.co.nz/__data/assets/pdf_file/0017/26324/FNZ14Dugdale1988.pdf. dead.
3. Meyrick. Edward. 1884. A Monograph of the New Zealand Geometrina. Transactions and Proceedings of the New Zealand Institute. en. 16. 49–113. Biodiversity Heritage Library.
4. Book: Hudson, G. V.. New Zealand moths and butterflies (macro-lepidoptera). Newman & Co.. 1898. London. 68. 10.5962/bhl.title.7912.
5. Book: Seitz, Adalbert . The Macrolepidoptera of the world : a systematic account of all the known Macrolepidoptera . 1920 . Fritz Lehmann Verlag . 12 . Stuttgart . 265.
6. Craw . R. C. . April 1987 . Revision of the genus Helastia sensu stricto with description of a new genus (Lepidoptera: Geometridae: Larentiinae) . New Zealand Journal of Zoology . en . 14 . 2 . 269–293 . 10.1080/03014223.1987.10422997 . 0301-4223.
7. 460.
8. Book: Hudson, G. V.. New Zealand moths and butterflies (macro-lepidoptera). Newman & Co.. 1898. London. 144. 10.5962/bhl.title.7912.
9. Book: Hudson, G. V.. The butterflies and moths of New Zealand. Ferguson & Osborn. 1928. Wellington. 111.
10. Book: Patrick, Brian. Conservation status of two rare New Zealand geometrid moths. 2000. Dept. of Conservation. New Zealand. Department of Conservation.. 0478219466. Wellington, N.Z.. 54078998.
11. Philpott. A.. 1901. Catalogue of Southland Lepidoptera. Transactions and Proceedings of the New Zealand Institute. 33. 167–185.
12. Book: Patrick, B. H.. Valley floor Lepidoptera of Central Otago. Department of Conservation. 1994. Dunedin. 54.
13. Hoare. R. J. B.. Dugdale. J. S.. Edwards. E. D.. Gibbs. G. W.. Patrick. B. H.. Hitchmough. R. A.. Rolfe. J. R.. 2015. Conservation status of New Zealand butterflies and moths (Lepidoptera). New Zealand Threat Classification Series. 20. 1–13.
14. 133. free.