Archiearinae (sensu Fletcher, 1953)

Young, Catherine J., 2006, Molecular relationships of the Australian Ennominae (Lepidoptera: Geometridae) and implications for the phylogeny of the Geometridae from molecular and morphological data, Zootaxa 1264 (1), pp. 1-147 : 1-147

The Tasmanian Archiearinae

The Tasmanian endemic alpine genera Dirce and Acalyphes have been variously assigned in the past to the Oenochrominae , Larentiinae and Ennominae ( Meyrick 1892; Prout 1910; Turner 1922, 1926). However Meyrick (1892) referred to the generalised structure of Dirce and both Meyrick and Prout noted a possible Dirce ­ Archiearis Hübner association. Subsequently, in 1986, McQuillan assigned the five described species to the Archiearinae (sensu Fletcher 1953) . The Tasmanian Archiearinae are believed to be most closely related to a group of two genera of southern Andean species assigned to the Archiearinae by Fletcher (1953), Archiearides fidonioides , A. pusilla Butler and Lachnocephala vellosata Fletcher. The remaining archiearine taxa inhabit the Palaearctic. Despite their absence from mainland Australia and New Zealand, it has been construed that the Australian Archiearinae are Gondwanan relicts ( McQuillan 1986).

Dirce lunaris and D. solaris

In this analysis D. lunaris and D. solaris were strongly supported as sister species (sequence divergence = 1.1%, 28S D2) (Fig. 10). These two species are sympatric and the caterpillars feed on the same host plant, the alpine shrub Epacris serpyllifolia R. Br. (Epacridaceae) over autumn. Adults fly in late spring to mid­summer and D. lunaris is usually present in far greater numbers than the rarer D. solaris . The moths of these species occur in alpine heathland in the Tasmanian highlands; however the known distribution of D. solaris is more limited, possibly due to under­collection. The adults of both species are rapid and low flying. Superficially the moths are of the same size, have cryptically coloured forewings and flash colouration on the hindwings. The hindwings of D. lunaris are white encircled by a dark grey band; whereas the centre of the hindwings of its sister species is a bright yellow, similar to the wing colouration of their congener Dirce aesiodora , the Holarctic archiearine, Archiearis parthenias and the Neotropical archiearine Archiearides fidonioides . The moths of all species of Dirce rest with the forewings completely covering the hindwings and folded planiform above the body. Superficial features of Dirce and Acalyphes are summarised below under Monophyly of the Tasmanian Archiearinae .

The two species share the following characteristics:

Male genitalia (Figs 44–47)

­uncus, moderately long, narrow, apically acute, rod­like with narrow base; small pendulous socii; gnathos, well­developed with very broad arms, V­shaped, terminating in one spine; simple, relatively wide valvae; broad transtilla; processes of the anellus large in both species, lobe­like in solaris , hollow and pouch­like in lunaris , not setose, not articulated to juxta and sub­joined basally in D. solaris ; cornuti rod­like attached to vesica.

Female genitalia (Figs 48, 49)

­large flattened stellate signum in D. lunaris ; signum absent in D. solaris ; ductus bursae, wide and sclerotised, with longitudinal folds (narrower in solaris ); large membranous corpus bursae; relatively short apophyses anteriores; large, well­sclerotised lamella postvaginalis.

Larvae (e.g. Fig. 50)

The caterpillars of both species have characteristically ennomine features and are very similar superficially. Larvae are moderately stout. The spinneret is relatively long whereas in most geometrids the spinneret is short. However in this study, long spinnerets were also noted in the nacophorines A. zalosema , Chlenias , Fisera , M. privata , P. porphyrinaria , P. fucata and T. selenaea , the boarmiine Gastrinodes Warren and the sterrhine S. perlata . Very short setae are present in the first instar larvae. This is also characteristic of Acalyphes , the Geometrinae , Oenochrominae s. str., several Boarmiini , the macariine D. exsuperata and the nacophorine P. innotata . Chaetotaxy is typically ennomine. Significantly SV2 is absent and SV3 present on A1 whereas in Holarctic archiearines, e.g. Archiearis , both SV2 and SV3 are characteristically absent on A1 ( McGuffin 1956, 1958). SV1, SV3 and V1 on A1 and L3, SV1 and V1 on A3–5 are in vertical alignment; however these attributes are common in the Nacophorini and other stout caterpillars (unpubl. data). Extra prolegs are not present on the abdominal segments in contrast to the Holarctic Archiearinae where the full complement of prolegs is present. Four lateral setae are present on the A6 proleg, similar to many Nacophorini and Boarmiini , and some Macariini and Larentiinae (unpubl. data). The crochet arrangement in the first instar larva is a uniordinal incompletely interrupted mesoseries and in the mature larva a biordinal interrupted mesoseries; arrangements that are widespread throughout the Geometridae ( Stehr et al. 1987) .

The main morphological difference between D. lunaris and D. solaris is the absence of a signum in the latter.