Fauna of New Zealand 72: Micropterigidae (Insecta: Lepidoptera) - Introduction
Gibbs, G W 2014. Fauna of New Zealand. 72, 127 pages.
(
ISSN 0111-5383 (print),
ISSN 1179-7193 (online)
;
no.
72.
ISBN 978-0-478-34759-3 (print),
ISBN 978-0-478-34760-9 (online)
).
Published 30 Jun 2014
ZooBank: http://zoobank.org/References/D6BC8C34-6D93-4EC7-BCB3-5670B2CFE744
DOI: 10.7931/J2/FNZ.72
Introduction
The family Micropterigidae, comprising more than 140 species world-wide (Zeller-Lukashort et al. 2007), is regarded as the most basal of living lepidopterans (Kristensen, 1984, 1998). These small moths, with wingspans between 5 and 12 mm, occur worldwide on all continents and several continental islands. The fossil record supports the contention of antiquity with exquisite examples from Lebanese amber, dated about 136 Ma (Azar et al. 2002), which closely resemble living taxa in both size and external morphological features. Additional amber micropterigid fossils are from Myanmar dated 93–100 Ma (Declòs et al. 2007) and Baltic amber dated 37 Ma (Pervosky et al. 2007), implying that these moths have survived world-wide without significant phenotypic change since the end of the Jurassic. One of the Baltic amber examples, Baltimartyria Skalski, has provisionally been interpreted as a member of the ‘southern sabatincoid’ clade (Mey 2011). It is noteworthy that their lifestyles are frequently independent of flowering plants (Angiospermae), on which the higher Lepidoptera are so dependent, with larvae that are liverwort-feeders and mandibulate adults which can feed on a wide range of spores from ferns, lycopods, and possibly bryophytes. Many micropterigids visit the flowers of angiosperms (Fig. 49), especially grasses and sedges (Fig. 53), to feed on pollen, and the larvae of some European species are known to browse angiosperm seedlings. In New Zealand, the moths are characteristically golden or metallic and are most often seen flitting in the semi-shade of forest or shrubland understorey, close to the ground.
To set this SW Pacific regional fauna in context, it is necessary to consider the overall pattern of diversity in the family Micropterigidae as revealed by recent molecular studies (Kobayashi et al. 2001, Gibbs et al. 2004, Lees 2010, Gibbs & Lees 2014) and from previous morphological understanding. A primary dichotomy was initially recognised by Kristensen & Nielsen (1979), who delineated a Micropterix-group in the northern hemisphere and a Sabatinca-group which included the remainder of known taxa in both northern and southern hemispheres. Since then many new taxa have been discovered, especially around the southern hemisphere, leading to reassessment of this dichotomy. Although the post-1979 literature has not shaken the validity of the ‘Micropterix-group’, the integrity of the ‘Sabatinca-group’ has been challenged (Gibbs 1983, Kristensen & Nielsen 1982, 1983, Kaltenbach & Speidel 1982, Minet 1985). However, apart from the recognition of a distinct ‘Australian-group’ (Gibbs 1983), and a discussion of the validity of the Sabatinca-group in the Pacific region (Minet 1985), no further consideration of SW Pacific micropterigid lineages was published until Gibbs (2010) revised the Australian fauna. The molecular studies, initiated by Yukimasa Kobayashi (Kobayashi et al. 2000) based on the 16S rRNA gene and now extended to include 18S and COI, (Kobayashi, pers. comm.), Gibbs & Lees 2014), provide evidence for five lineages of world genera, each with a predominantly discrete geographical distribution, two in the northern hemisphere, three southern: 1) the original Micropterix-group in Europe and Asia; 2) the ‘Australian group’, dominated by Tasmantrix Gibbs in eastern Australia and including Aureopterix Gibbs from New Caledonia and Queensland and Zealandopterix Gibbs from New Zealand, as well as a newly-discovered West Australian taxon; 3) an E Asian/North American lineage centred between Japan and Taiwan (Neomicropterix Issiki,Kurokopteryx Hashimoto, Palaeomicroides Issiki, Paramartyria Issiki,Issikiomartyria Hashimoto); Vietnam (Vietomartyria Hashimoto & Mey), and North America (Epimartyria Walsingham); 4) the Sabatinca lineage largely confined to New Zealand and New Caledonia but with an undescribed outlier in SW Australia; and 5) a widely distributed, but more weakly supported, southern hemisphere group extending from South Africa (Agrionympha Meyrick, +1 new genus), and Madagascar (2 new genera), to Australia (Austromartyria Gibbs), Chile (Hypomartyria Kristensen & Nielsen), Ecuador, and Costa Rica (at least 2 new genera), which are referred to loosely as the ‘southern sabatincoid’ taxa (Gibbs et al. 2004, Gibbs & Kristensen 2011, Gibbs & Lees 2014). This group also includes Squamicornia Kristensen & Nielsen, from Ecuador.
As discussed above, two of the lineages occur in New Zealand; the majority in the genus Sabatinca, now defined to include 70 species known to the author, which are largely confined to the 90% submerged continental plate of Zealandia (sensu Mortimer 2008), and distributed between the emergent islands of New Caledonia and New Zealand. The majority of the undescribed taxa in this lineage (50+) are from New Caledonia. The Australian-group lineage (of 11 species with two undescribed taxa from Western Australia) is represented in New Zealand by a single northern North Island species (Zealandopterix zonodoxa).