FNZ 30 - Hepialidae (Lepidoptera) - Introduction
Dugdale, JS 1994. Hepialidae (Insecta: Lepidoptera). Fauna of New Zealand 30, 164 pages.
( ISSN 0111-5383 (print), ; no. 30. ISBN 0-478-04524-7 (print), ). Published 01 Mar 1994
The ghost moths or swift moths belong to the Hepialidae, the largest family in the lepidopteran superfamily Hepialoidea. The family has around 500 described species worldwide, most of them in South America (Nielsen & Robinson 1983), but there is considerable diversity in South Africa (Janse 1942) and in Australia (Common 1990). In New Zealand twenty-seven species in seven genera are now recognised. The name 'ghost moth' is based on the European Hepialus humuli Linnaeus, males of which appear ghostly white.
In New Zealand, Australia, and southern South America swift moths sporadically or regularly occur in huge numbers, and have a significant impact on human activity. Larvae of 'porina' (Wiseana species) in New Zealand and 'corbies' (Oncopera species) in Australia affect pasture production. The puriri moth, Aenetus virescens (Doubleday), is not only our largest moth species (females can exceed 140 mm wingspan) but is abundant in several North Island cities and towns. Damage by its larva to beech (Nothofagus) trees has curtailed their use for timber and veneer, and thus assisted the perpetuation of their role as watershed protection forests. In parts of eastern Australia, sale of reared adults of the related lizard-head moth, Zelotypia stacyi (Scott), augmented the incomes of some residents in the early 1900s. Even the parasitic fungus Cordyceps has - or had - some commercial value: the mummified caterpillars with the elongate fruiting body attached were sold to tourists travelling through the Mamaku Plateau (BP). The ground-up fruiting body was also used by Māori as an ingredient in tattoo pigment (Best 1912).
Hepialidae in New Zealand have several values: (a) scientific - as all our species are endemic, and the genera they are placed in can be distinguished from genera in other countries, their biodiversity and systematic values are high; (b) economic - porina are significant competitors with farm stock for pasture; (c) conservation - many species have restricted distributions, most are striking in appearance and size, and many are restricted to unmodified or relatively unmodified biotopes including forest, shrubland, wetlands and cushion bogs, or penalpine or alpine swards, the last three in the absence of cattle. Above all, they are a distinctive and significant part of Aotearoa / New Zealand, and some of them are among the bigger and more elegantly patterned hepialids on Earth.
Despite their abundance (Dumbletonius, Wiseana) or huge size (Aenetus), their presence in lowland sites, their regular periodic adult emergences (flights), and their attraction to light, it is curious that no Hepialidae were brought to England from New Zealand by naturalists on Cook's voyages. Upon each visit, long periods were spent anchored close to shore in Queen Charlotte Sound (SD) during the flight season of Dumbletonius and Wiseana, and again, Cook's survey of Dusky Sound (FD) took place during the flight season of the large, robust Aoraia species. Male Aoraia are suicidally attracted to most light sources.
The earliest hepialid specimens from New Zealand were sent to London (and possibly Germany) by Ernest Dieffenbach in 1840 and by J.G. Children at about the same time. Dieffenbach's specimen has not been located; it was described by Doubleday in 1843. With the establishment of Auckland as a major settlement - and, briefly, as capital city - more specimens were sent, collected by Dr Andrew Sinclair and Lt Col. Daniel Bolton. From Hawkes Bay William Colenso sent D. characterifer, and more Aenetus were sent by Percy Earl in 1845 and by a Mr Churton in 1851. Francis Walker at the British Museum published descriptions of four species, but only one of these is now regarded as valid.
With increasing European settlement and exploration came increasing numbers of specimens. Francis Walker described species (only two now regarded as valid) collected by T.R. Oxley from Nelson, but recorded as from Auckland; Achille Guenée in Paris described material sent from Christchurch by the lawyer R.W. Fereday; and yet another synonym (fischeri) of A. virescens was described by Dr C. Felder, on the strength of a specimen collected at Auckland during the voyage of the Austrian frigate 'Novara'. By 1880 the British Museum had received two large collections, one from Otago by Dr James Hector, the other from Canterbury and Hawkes Bay by J.D. Enys. A.G. Butler described species of Hepialidae from both collections.
Meanwhile, back in the colony, local expertise was developing. Sir Walter Buller described and illustrated a large ('in, 11 lines') hepialid adult found by him in the Ruahine Ranges (HB). Buller's specimen, erroneously reported as lost at sea (Hudson 1898), was probably landed at London (Meads 1990) and may have been purchased by a private buyer. No convincingly similar recent specimen has been collected. Edward Meyrick collected extensively in New Zealand during 1880-86, and struck up a friendship with G.V. Hudson of Wellington and later, by correspondence, with Alfred Philpott of Invercargill. All three described Hepialidae, publishing in the Transactions of the New Zealand Institute.
Up until L.J. Dumbleton's studies (published 1966), three genera were recognised: Charagia Walker (for Hepialus of authors), Porina Walker (a preoccupied name), and Wiseana Viette. Dumbleton swept all that away, put the puriri moth in Aenetus (following N.B. Tindale's work in Australia), defined four new genera, and recognised and rearranged (or synonymised) the Wiseana species. Wiseana as a genus was appropriately defined (as Philpottia) by Paul Viette in Paris, 98 years after Achille Guenée had worked there on New Zealand Hepialidae. K.A.J. Wise had advised Viette that the name Philpottia was preoccupied, so Viette in 1961 gratefully named New Zealand's second most significant pasture pest group after him.
Since Dumbleton's study, most work in New Zealand has concentrated on pasture-inhabiting Wiseana (porina) biology in relation to control measures. Interpretations of these studies were affected by the considerable complexity of many porina populations and the large differences in population make-up between localities. These complexities are becoming better understood; for example, compare Helson (1967) and Barratt et al. (1990). Today, field work in both production pasture and 'natural' biotopes, notably by B.I.P. Barratt, N. Barlow, A. Carpenter, J. Grehan, and B.H. Patrick, has revealed a highly complex fauna with areas of surprisingly high diversity, e.g., the Wiseana complex in the South Island and the Aoraia complex in certain contiguous Central Otago mountain ranges.