Acalyphes sp.

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

Acalyphes sp. and A. philorites

The relationship between these two species was very strongly supported from all data sets and the sequence divergence between the two was 0.0% (28S D2) and 1.9% (EF 1­).

A. philorites was first placed into the Larentiinae by Turner (1926) on the basis of a typically larentiine wing venational character, the fusion of Sc + R 1 with Rs in the hindwing for more than ¼ length of the cell. Subsequently, based on mainly superficial similarities, Acalyphes was moved to the Archiearinae by McQuillan and Edwards in 1996.

The adults of A. philorites have a relatively extended flying period from late spring to late summer. Females appear in the latter half of this period. The known distribution of this species is similar to that of Dirce aesiodora except that it extends further south in Tasmania to south of Frenchmans Cap (42°16S, 145°49E). Adults have typically cryptically coloured and patterned forewings in varying shades of greyish­brown, black, grey and white and the hindwings are an almost uniformly pale greyish­brown. These moths are active during periods of bright sunshine in the Tasmanian mountains and are relatively easy to intercept. They rest with forewings held tent­wise above the body and the hindwings covered. Males have been observed feeding on the flowers of Pentachondra pumila R. Br. on the Algonkian Mountain in Tasmania. Larvae feed on the Tasmanian Pencil Pine Athrotaxis cupressoides , similar to D. aesiodora , where they are well camouflaged against the bright green foliage.

By contrast the undescribed species of Acalyphes flies during late autumn and so far has only been recorded from Mt Field in southern Tasmania. However larvae were reared from eggs on Microstrobos niphophilus (similar to D. oriplancta and Dirce sp. ) and so the species is likely to be found in other areas of Tasmania colonised by its host plant. Adults of this species resemble philorites but are duller and relatively unmarked in appearance. Both Acalyphes species lack the flash colouration of Dirce . The females of Acalyphes sp. are relatively sedentary and have reduced tympana, adaptations that are most likely a result of the harsh, cold and windy conditions present in late autumn at high altitudes in Tasmania. Similar adaptations are present in geometrids such as the Palaearctic winter moth Alsophila whose females are apterous and lack tympana. Adults of Acalyphes sp. fly low over the alpine foliage in sunshine and for short distances only. Similar to its congener, the females are more numerous towards the end of the flying period. Superficial attributes of Acalyphes are described below in Monophyly of the Tasmanian Archiearinae .

Shared features

Male genitalia (Figs 65–68)

—acute, narrow uncus; small, pendulous socii; well­developed gnathos with broad arms, V­shaped with several terminal spines; processes of the anellus, long and slender, articulated; small juxta; simple, narrow valvae; aedeagi, slender, markedly curved, apically acute, cornuti absent.

Female genitalia (Figs 69, 70)

—wide ovipositor; relatively long membranous colliculum; very short ductus bursae; small membranous corpus bursae; signum absent.

The genitalia of these two species are very similar, which supports their placement into the same genus. The only differences between them are:

—the processes of the anellus in A. philorites are relatively longer; apex of the valva is blunt in A. philorites but curved in Acalyphes sp. ; the juxta in A. philorites is almost divided into two lobes whereas it is undivided in Acalyphes sp. ; aedeagi appear to be almost identical except that in A. philorites it is relatively more narrow.

Eggs (Figs 71–73) ( Young 2006, in press)

The eggs of the two species are also very similar. Acalyphes ova are moderately broad, bluntly ovoid and with the anterior pole slightly angled to the micropylar axis. The egg is marked all over by hexagonal flat cells which are relatively more clearly defined in Acalyphes sp. than the generally barely discernible cell form in A. philorites . Aeropyles are slightly elevated with small openings and are distributed on the anterior pole and narrow lateral sides. The rosette and secondary micropylar cells are recessed. The chorion of Acalyphes sp. is more rugose than that of the other species. Acalyphes sp. eggs are further distinguished by the multiple aeropyles or pores arranged along the cell walls.

Larvae (Fig. 64)

—moderately stout larvae; very short setae on first instar larvae; short spinneret; SV2 absent on A1; SV3 present on A1–5; SV1, SV3 and V1 vertically aligned on A1; L3, SV1 and V1 on A 3–5 in vertical alignment; four lateral setae on A6 proleg; extra vestigial prolegs present on A3–5; no crochets present in first instar; crochet arrangement a biordinal incompletely interrupted mesoseries in mature larvae; truncated, rounded hypoproct.

As in Dirce , the chaetotaxy of Acalyphes is typically ennomine and atypical of the Archiearinae .

Pupae

The pupae of the two species are almost identical and share the following features:

—smooth cuticle; short setae; exposed, large labium; fore­femora not exposed; tips of meta­tibia exposed, large and pendulous; small, under­developed mesothoracic spiracles; small, shallow, randomly, densely distributed punctures on A1 –8; absence of A5 spiracular furrow; moderately well­developed dorsal groove; weak lateral groove; four pairs of hooked cremastral setae, terminal pair relatively more robust, diverging apically.

The monophyly of Acalyphes is also well secured by molecular and morphological data. However, contrary to Dirce , there is little morphological evidence to separate this genus from the Nacophorini . Acalyphes possesses articulated processes of the anellus (Figs 65, 66), the anterior pole the of the ovum is angled to horizonatal axis [as found in the Paralaea group in the Australian Nacophorini ( McQuillan et al. 2001) ], extra larval prolegs, four pairs of cremastral setae and short pupal setae, characteristics that are widespread in the Australian Nacophorini ( McQuillan 1981, 1984, 1985, 1996; McQuillan et al. 2001; Young & McQuillan 2001, 2003) From this evidence, Acalyphes is most likely closely related to the Australian Nacophorini .