Notoreas perornata (Walker, 1863)

Figs. 2–61 (adults); 62–71 (male genitalia); 72–76 (female genitalia)

Fidonia perornata Walker, 1863. List of the specimens of lepidopterous insects in the collection of the British Museum XXVI: 1672.

Notoreas simplex Hudson, 1898. New Zealand Moths and Butterflies (Macro-lepidoptera): 74. New synonymy.

Lythria regilla Philpott, 1928. Transactions and Proceedings of the New Zealand Institute 58: 360. Reinstated synonymy (synonymised with N. perornata by Hudson (1939: 412) and with N. simplex by Patrick et al. (2010: 272)).

Diagnosis. As noted by Patrick et al. (2010), all populations of N. perornata can be distinguished from the other, very closely related members of this complex, N. elegans Patrick & Hoare, N. casanova Patrick & Hoare and N. edwardsi Patrick & Hoare, by the absence of distinct orange streaking interrupting the white of the forewing postmedian line on the upperside (streaking present in elegans, casanova and edwardsi). The second character given by Patrick et al. (2010) as diagnostic of elegans, casanova and edwardsi, i.e. the presence of a small white subapical streak arising from the subterminal line, does not seem to be entirely reliable, as this streak occurs in some specimens of some populations of N. perornata. Notoreas elegans and N. casanova have the postmedian line crenulate above the angulation in the disc, whereas it is smooth in N. perornata and N. edwardsi. Notoreas edwardsi can be distinguished from all the other species by its strongly reduced black markings on the underside of both forewing and hindwing (Patrick et al. 2010: figs 8F, 8G). No consistent differences have been noted in the genitalia of the four species.

Type material. Fidonia perornata: Holotype: Male, ‘Type’, ‘New Zeal / 53-19’, ‘ Fidonia perornata’ (NHMUK) (examined).

Notoreas simplex: Holotype: Female [Mt Arthur Tableland, 7 Jan 1891, 3400 ft, G. V. Hudson] (MONZ) (examined).

Lythria regilla: Holotype: Male (Figs 45, 50), ‘ Dun Mt. 3000 ft 8-1-22 A. Philpott’, ‘ Lythria regilla Philpott Holotype ♁’, ‘ N.Z. Arthropod Collection, NZAC Private Bag 92170 AUCKLAND New Zealand’ (NZAC) (examined). Paratypes: 1 male, 1 female. NN: 1 male, Cobb Valley, 9 Dec 1922, A. Philpott; 1 female (labelled Allotype), Mt Starveall, 25 Jan 1926, A. Philpott (both NZAC). Note: Philpott (1928) mentions‘a series of paratypes in coll. Cawthron Institute’ in addition to the allotype, but only one of these has been located in NZAC.

Note on synonymy. Patrick et al. (2010) retained N. simplex as a distinct species but with some reservations. Both characters used in that paper to distinguish simplex from perornata (larger wingspan and presence of an enlarged ‘tooth’ in the forewing subterminal line) show overlap with specimens attributed to perornata from elsewhere in the South Island. Our mtDNA gene tree shows N. simplex deeply embedded in the southern clade of N. perornata with minimal barcode distances to other populations, so it seems untenable to continue to regard this as a separate species on current evidence. Notoreas regilla was synonymised with N. simplex by Patrick et al. (loc. cit.), and is regarded as a local colour-form of montane N. perornata as implied by Hudson (1939). It should be noted that there is a distinct, possibly unnamed, montane species of Notoreas, not belonging to the perornata complex, that is often misidentified as N. regilla in New Zealand collections (Patrick et al. 2010).

Remarks. Notoreas perornata was fully redescribed by Patrick et al. (2010) and this description is not repeated here. We here recognise 10 groups of populations within the species, grouped into two clades based on the mtDNA gene tree. The two clades cannot be satisfactorily diagnosed based on morphology as, to a large extent, they show parallel evolution of wing traits.

Treatment of populations. Populations have been numbered according to their position on the COI tree: the ‘northern clade’ (Northland ND to Castlepoint WA) is 1 and the ‘southern clade’ (southern Wairarapa WA to Kaitorete Spit MC) is 2. Within these clades, allopatric populations or groups of populations regarded as differing in range of morphological variation (size, wing pattern) are treated separately and each is accorded a separate letter (1a, 1b etc.); each is proposed here as a ‘conservation unit’, based on the precautionary principle and to maximise (in theory) future evolutionary potential. In one case (north-west Nelson coastal populations, 2b), a separate conservation unit is proposed based only on the COI results since the incomplete sequence recovered places these populations in a separate branch from the morphologically indistinguishable Taranaki coastal populations (1c). The Westland population is tentatively included in clade 2 based largely on geographic location; DNA sequencing failed for this population. An anomalous specimen from Rarangi SD (2c* in Fig. 1) was placed as sister to the rest of N. perornata in the mtDNA gene tree; this is discussed under 2c.