Neritodes verrucata

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

Neritodes verrucata and Psilosticha mactaria

The taxonomic status of N. verrucata is uncertain and at present its tribal placement is undetermined ( McQuillan & Edwards 1996). Similarly the placement of P. mactaria is also in doubt as, although superficially boarmiine­like, the genitalia are not typical (Figs 75–77). In fact characteristics of the genitalia and immature stages of this species support its placement in the Macariini , a classification also supported by the molecular data which links both species with the macariine Dissomorphia australiaria , although unsupported (Fig. 10). The sequence divergence between these two species is 11.7%, between D. australiaria and P. mactaria 14.3% and D. australiaria and N. verrucata 10.6% (Appendix 6).

The six described species of Psilosticha occur in southern Australia. P. mactaria adults occur in two forms. The larger specimens inhabit high altitude including sub­alpine areas where the larvae have been recorded feeding on Hakea lissosperma R. Br. and H. microcarpa R. Br. (Proteaceae) (unpublished data). Adults are medium­sized moths and resemble boarmiines superficially. Wings are triangular, and both forewings and hindwings are similarly cryptically patterned with white irrorated with grey. The moths rest with wings flattened on to the substrate with both fore­ and hind­wings exposed. Moths of the lower altitude populations are found in dry sclerophyll forests where the larvae feed on the legume Pultenaea juniperina Labill. Similarly , many Afrotropical macariines feed on legumes and Krüger (2001) considered this to be the primitive condition. No genitalic differences can be detected, although there is an apparent size difference in these forms, and they are therefore unlikely to be different species.

The presence of sub­apical horns on the uncus of the male genitalia of P. mactaria (Fig. 75) is strong evidence that this species is a macariine, although the species lacks other typical macariine feature i.e. divided valvae, large chaetosemata or a cleft, excavated or emarginate sternum eight ( Scoble & Krüger 2002). However the male genitalia (Figs 75, 76) resemble strongly that of the only macariine illustrated by Hollway (1994) and Scoble and Krüger (2002) that has an undivided valva, the distinctive and rare Bornean species Lampadopteryx scintillans Warren ( Holloway 1994) and this may indicate some degree of relatedness. Features that P. mactaria shares with this species are ciliate antennae, undivided valva, sacculus separated into a separate lobe, coremata originating from the anellifer and an extended and recurved saccus (Fig. 75). Differences are the presence of a setal comb on A3 and gnathos (although weak) that are only present in Lampadopteryx Warren although the absence of a setal comb is more typically macariine. The aedeagal vesica of the Bornean species also has only two distinct cornuti compared to the multiple and brush­like cornuti of P. mactaria (Fig. 76). The female genitalia in P. mactaria (Fig. 77) have a large well­developed, stellate signum whereas this structure is absent in Lampadopteryx .

Only one other species of Psilosticha Meyrick , P. pristis , was available for comparison and only the male genitalia were examined (not illustrated). This species does not possess typical macariine features and the genitalia bear little resemblance to that of mactaria . However the genitalia have many typical boarmiine features, such as: very short, basally wide and simple uncus; weak gnathos; poorly developed socii; very short tegumen; narrow complex valvae; sclerotised costa; pad­like, setose harpe; elongated, narrow juxta. This species, therefore, is most likely not congeneric with Psilosticha and, on the possession of socii, may be be close to Ectropis excursaria (see discussion below).

Evidence for the placement of P. mactaria in the Macariini is also apparent from egg morphology. The eggs greatly resemble those of the Australian macariines ‘Boarmia’ penthearia Guenée, Dissomorphia australiaria and Parosteodes Warren and share few common features with described boarmiine eggs (Fig. 78) ( Young 2006, in press).

However larval features do not generally separate P.mactaria from the Boarmiini . The caterpillars of the two Australian macariines examined in this study, Dissomorphia australiaria and Parosteodes fictiliaria , and P.mactaria share typically boarmiine features such as very short to medium length setae on the first instar larvae, typically ennomine chaetotaxy [although, unusually, SV 2 is present on A1 of the Afrotropical macariine Isturgia deeraria Walker ( Krüger (2001)], four lateral setae on the A6 proleg, absence of extra prolegs, crochet arrangement in first instar larve a uniordinal completely interrupted mesoseries and in the mature larve a biordinal uninterrupted mesoseries. This apparent resemblance to the Boarmiini is supported by the 28S D2 analysis that places the Macariini within the Boarmiini (Fig. 10); although this is unsupported. Interestingly the larvae of P. mactaria have two colour forms, brown and green. Such dimorphism was also noted as typical of the Macariini ( Semiothisa Hübner , Itame Hübner and Ixala Hulst ) by McGuffin (1987).

Similarly characteristics of the pupae of the two Australian macariines examined in this study, and P. mactaria are typical of the Boarmiini , i.e. bifurcate cremaster, long setae (although short in P. mactaria ) and A5 spiracular furrow. Krüger (2001) also noted the presence of these features in the Afrotropical taxa Platypela Warren, Isturgia Hübner and Chiasmia Hübner , although setae are short in these macariines and a spiracular furrow is absent in Platypela. In D. australiaria the dorsal and lateral groove are also well developed whereas in the other Australian and Afrotropical taxa theses structures are absent.

N. verrucata is relatively more difficult to place as a macariine and no data on immature stages for this species are available. This species is widespread in heathy vegetation and occurs in south­eastern Australia. The adult is moderate in size, with ciliate antennae and very pale brown forewings and off­white hindwings. An unusual autapomorphy for the genus is the presence in the male of a moderately large, raised, membranous, disc­like structure positioned between CuA and the anal vein on the venter of the forewing at about ¼ the way proximally along the length of the cell that is densely covered with fine scales. The species does not possess typical adult features such as uncal horns or a divided valva, however the genitalia resemble that of its sister species, P. mactaria , in this analysis and significantly, and unlike P. mactaria , extended chaetosemata are present. Both species share a separated lobe­like sacculus, extended and recurved saccus, coremata originating from the anellifer and lack of a gnathos (Figs 75, 79). The female genitalia also appear similar in general form but N. verrucata lacks a signum (Figs 77, 81).