IBE-JGZ: one male and one female, New Caledonia, Aoupinié, refuge, -21.14890 165.32348, 400 m, 29.xi.2008, leg. M. Wanat, beating rainforest, Acronymolpus bertiae (Jolivet, Verma and Mille) J. Gómez-Zurita det. 2017. HNHM: (1) one male, New-Caledonie, Col d’Amieu, 19.i.1977, leg. Dr. J. Balogh, Acronymolpus bertiae (Jolivet, Verma et Mille) J. Gómez-Zurita det. 2017. MNHW: (1) two females, New Caledonia, Col d’Amieu (6.5–7.0 km from gate), 21°35.2'S, 165°46.4'E, 450–470 m, 6.i.2007, leg. M. Wanat & R. Dobosz, night coll.; (2) one male, New Caledonia, Col d’Amieu (3 km from gate), 21°35.1'S, 165°47.8'E, 500 m, 6.i.2007, leg. M. Wanat, Acronymolpus bertiae (Jolivet, Verma et Mille) J. Gómez-Zurita det. 2017; (3) one male, New Caledonia, Col d’Amieu (3.0 km to gate), -21.58536 165.79319, 500 m, 16.xi.2008, leg. M. Wanat, Acronymolpus bertiae (Jolivet, Verma et Mille) J. Gómez-Zurita det. 2017; (4) one female, New Caledonia, Farino, Parc des Grandes Fougères, Pic Vincent track, -21.60948 165.77459, 600–670 m, 17.xi.2008, leg. M. Wanat; (5) one male and one female, New Caledonia, Farino, Parc des Grandes Fougères, track & forest N of Pic Vincent, -21.59929 165.77519, 670 m, 17.xi.2008, leg. M. Wanat, Acronymolpus bertiae (Jolivet, Verma et Mille) J. Gómez-Zurita det. 2017; (6) one male, New Caledonia, Sarramea, trail to Dogny, -21.6229 165.8684, 300–560 m, 9.xi.2010, leg. M. Wanat & R. Ruta, Acronymolpus bertiae (Jolivet, Verma et Mille) J. Gómez-Zurita det. 2017; (7) one male and one female, New Caledonia, Aoupinié, road to sawmill, 21°09'S, 165°19'E, 420–530 m, 7.ii.2004, leg. M. Wanat; (8) two males, New Caledonia, Aoupinié, gate to meteo station, 21°11'S, 165°17'E, 900–950 m, 8.ii.2004, leg. M. Wanat; (9) one female, New Caledonia, Aoupinié, Goipin road jct., 21°10.8'S, 165°18.1'E, 730 m, 17.i.2007, night coll., lamp & beating, leg. M. Wanat & R. Dobosz; (10) three males, New Caledonia, Aoupinié, 21°11.0'S, 165°17.5'E, 850–900 m, 18.i.2007, leg. M. Wanat & R. Dobosz; (11) two females, New Caledonia, Aoupinié, 21°11.0'S, 165°17.6'E, 650–800 m, 19.i.2007, leg. M. Wanat; (12) one male, New Caledonia, Aoupinié, -21.17539 165.30952, 700 m, 27.xi.2008, leg. M. Wanat; (13) one female, New Caledonia, Aoupinié, -21.18151 165.30048, 790–830 m, 27.xi.2008, leg. M. Wanat; (14) three males and one female, New Caledonia, Aoupinié, refuge, -21.14890 165.32348, 400 m, 29.xi.2008, leg. M. Wanat, beating rainforest; (15) one male, New Caledonia, Aoupinié, -21.18027 165.30005, 800–830 m, 20.xi.2010, ex Pycnandra benthami, leg. M. Wanat & R. Ruta; (16) six males and two females, New Caledonia, Aoupinié, Goipin rd jct to gate, -21.1814 165.2879, 850–900 m [one with: 700–900 m], 20.xi.2010, leg. M. Wanat & R. Ruta; (17) one male and two females, New Caledonia, Aoupinié, meteo station to summit, roadside, -21.1788 165.2786, 950 m, 21.xi.2010, leg. M. Wanat & R. Ruta.

Jolivet et al. (2007) described Stethotes bertiae based on three specimens collected at Col d’Amieu and compared the new species with S. minuta Jacoby, S. similis Gressitt and S. mimica Gressitt, all endemic from New Guinea (Gressitt 1966; Jolivet et al. 2007). The genus Stethotes was proposed with descriptions of nine species from Java, New Guinea, Borneo, and the Moluccas (Baly 1865–1867) and later shown to be particularly species-rich in New Guinea (Gressitt 1966; Medvedev 2009), but also recorded from other areas in the Australasian region, including Fiji and Samoa (Maulik 1929; Bryant and Gressitt 1957). In this geographic context, it seemed reasonable to find the genus in New Caledonia as well. But the finding of Stethotes bertiae had implications beyond the discovery of a genus that had not been previously recorded from New Caledonia and is not known from Australia either. Stethotes belongs to the tribe Typophorini, a lineage most diverse in the Old World, particularly in South East Asia and in the Western Pacific, and this lineage is also the one thriving in Fiji, with important biogeographic connections with New Caledonia (Keppel et al. 2009). Interestingly, the vast majority of Eumolpinae in New Caledonia belong to the tribe Eumolpini (Gómez-Zurita 2011a; Papadopoulou et al. 2013: note that in these works, the names Colaspoidini and Nodinini were used instead of Eumolpini and Typophorini, respectively). To our knowledge, the only exceptions were Rhyparida foaensis (Jolivet, Verma & Mille, 2007) and three species of Stethotes, incluiding S. bertiae (Gómez-Zurita 2011a).

The original description of S. bertiae was very generic, without much useful information on characters that could help in recognizing the correct generic placement of the species, except perhaps the two differentiated arrangements of elytral punctation: confused at basal half and aligned at apical half of elytra. However, the original description included a photograph of the holotype (Jolivet et al. 2007: 91). Stethotes bertiae has the size, the characteristic fusiform shape, the long antennae, the strong punctation (aligned at apical half of elytra), and most critically, entire tibiae of Acronymolpus, a character clearly showing that the species should not be placed in the Typophorini. Moreover, the revision of Acronymolpus included one species, A. meteorus Samuelson, also collected in the Col d’Amieu and the nearby Plateau de Dogny and sharing all the (apomorphic) peculiarities of S. bertiae. Among these, it is worth mentioning the heavy punctation of pronotum and basal half of elytra, the reddish testaceous coloration of abdominal ventrites, and the finely wrinkled hypomera, referred to as “with heavy isodiametric sculpture” by Samuelson (2015). There is no doubt that Samuelson's species is the same that had been described years earlier by Jolivet et al. (2007), and this claim was recently confirmed by G. Allan Samuelson himself, upon our exchange of opinions, by comparing the type of S. bertiae with his own specimens (G. Allan Samuelson, pers. comm.).

The original work describing Stethotes bertiae included a drawing of the penis, but as it is customary in contributions by the authors of this species, the sexual organ was shown in lateral view, which is of very limited utility for identification purposes (Gómez-Zurita 2011b). In turn, the description of A. meteorus lacked any reference to genital structures. The dissection of the new material available for this species showed that they are all males, and male genitalia could be prepared and described focusing on taxonomically relevant characters for the first time (Fig. 1a, c): the penis is narrow and slender, narrower in median part and curved in lateral view, with apex tapering and more strongly bent ventrally, as described by Jolivet et al. (2007); distal end is flattened dorsoventrally, with sides straight and converging to blunt apex with a short median notch. The dissection of the specimens of A. turbo, sympatric and syntopic (judging from collection data shown in labels) with A. meteorus in every one of the sites where this species has been found, showed that they were all females and, as mentioned above, are interpreted here as conspecific with A. bertiae. The spermatheca of the species is described here for the first time (Fig. 1e): spermatheca slender, with nodulus and cornu feebly curved and more or less at right or slightly obtuse angle; cornu thicker than nodulus and blunt at apex; nodulus with bulging insertion of spermathecal gland at middle; spermathecal duct inserted nearly at base of nodulus and bent abruptly.

Figure 1. 

Ventral and lateral views of the penises of a Acronymolpus bertiae (Jolivet, Verma & Mille) and b A. jourdani (Jolivet, Verma & Mille). Dorsal view of the distal ends of the penis of c A. bertiae and d A. jourdani. Spermathecae of e A. bertiae and f A. jourdani.

Based on this complete account, which takes into account geographical but mainly anatomical data and the recognition of sexual dimorphism in the species as described above, three taxonomic acts are necessary. The first is the transfer of Stethotes bertiae to the genus Acronymolpus, resulting in Acronymolpus bertiae (Jolivet, Verma & Mille, 2007), comb. n., and the other two are recognizing that A. meteorus (males) and A. turbo (females) are junior synonyms of this taxon; thus, Stethotes bertiae Jolivet, Verma & Mille, 2007 = Acronymolpus meteorus Samuelson, 2015, syn. n. and Acronymolpus turbo Samuelson, 2015, syn. n.

HNHM: (1) one male and one female, New-Caledonie, Mont Panié, 7.ii.1977, leg. Dr. J. Balogh, Acronymolpus jourdani (Jolivet, Verma et Mille) J. Gómez-Zurita det. 2017. MNHW: (1) one female, New Caledonia (N), Mandjélia (summit) 20°23.9'S, 164°31.9'E, 750–780 m, beating, montane rainforest, leg. M. Wanat & R. Dobosz, Acronymolpus jourdani (Jolivet, Verma et Mille) J. Gómez-Zurita det. 2017.

A few years after the description of S. bertiae, Jolivet et al. (2013) described another species of Stethotes, S. jourdani, very similar to the former but with subtler punctation and from localities further north in the island, in the Massif du Panié, including La Guen, Dawenia, and Wewec (Jolivet et al. 2013). As before, the species does not have any of the characters of the genus Stethotes, but these of Acronymolpus instead. Interestingly, it fits the description of the second blackish species of Acronymolpus described by A. Samuelson a couple of years later, A. gressitti, also collected from Mt. Panié. It is worth noting that both descriptions depart in a significant character: the size of the holotypes. The type of S. jourdani is reported as 4.0 mm long (Jolivet et al. 2013), while that of A. gressitti is 2.6 mm (Samuelson 2015). The measurement given by Jolivet et al. (2013) is far bigger than the largest Acronymolpus studied by Samuelson (2015). However, it is important to note that, judging from the figures in the article, the measurements in Jolivet et al. (2013) may not be reliable. Samuelsonia gomyi Jolivet et al., 2013 measures 2.5 mm and it shows slightly longer than the holotype of S. jourdani, figured alongside and possibly photographed with the same magnification as the former, since both show an identical scale bar of 2.0 mm (Jolivet et al. 2013, figs 7 and 8). Apart from this detail, the two species, S. jourdani and A. gressitti, match in their characters, as recognized by the author of the latter (G. Allan Samuelson, pers. comm.), including the four basal antennomeres paler, vertex deeply sulcate, smooth hypomera, and pronotal and elytral punctation smaller than in S. bertiae.

Moreover, additional material, even if limited, made it possible to draw an analogy with the previous case whereby A. joliveti could be recognized as the female of A. gressitti. The spermatheca of this species was known due to the description of A. joliveti, and the only information available on the male genitalia was a drawing of the penis in lateral view (Jolivet et al. 2013: fig. 1). The spermatheca of A. jourdani, figured here from a specimen from Mandjélia, is identical to that figured by Samuelson (2015) from a specimen from Mt. Panié (Fig. 1f). This spermatheca is very similar to that of A. bertiae, but shows some relevant differences, including a straight nodulus longer than cornu, conspicuously dilated at base and constricted medially at both ends of bulging insertion of spermathecal gland. Here, the first complete description of the penis of A. jourdani is provided and is a very useful character to distinguish this species from A. bertiae (Fig. 1b, d). The penis is similar to that of A. bertiae with a less pronounced ventral curvature and more gradually curved apex; and the apical end, as seen in dorsal view, has straight sides converging to an acute apex with a deep, narrow median cleft.

As before, three taxonomic acts are required, the first transferring Stethotes jourdani to Acronymolpus, to propose the new combination Acronymolpus jourdani (Jolivet, Verma & Mille, 2013), comb. n., and the second establishing that A. gressitti and A. joliveti are junior synonyms of this taxon, thus Stethotes jourdani Jolivet, Verma & Mille, 2013 = Acronymolpus gressitti Samuelson, 2015, syn. n. and Acronymolpus joliveti Samuelson, 2015, syn. n.

A third species of Eumolpinae originally ascribed to Stethotes, S. mandjeliae, was described based on several specimens collected near the summit of Mt. Mandjélia, in the northern part of the Massif du Panié (Jolivet et al. 2010). However, conversely to the other species of Stethotes described by the same authors, this species does not belong to the genus Acronymolpus. This species unmistakably fits the nominotypical subgenus of Taophila instead (Gómez-Zurita and Cardoso 2014), allied to T. subsericea Heller, 1916 and T. corvi Samuelson, 2010, and easily recognizable by the elongate shape, bicolor antennae, angulated sides of pronotum, which is darker than elytra, marked humeri wider than pronotum, and tapering elytra with partially aligned punctures and stiff hairs, amongst others. It remains to be seen if this species had been previously described by Samuelson (2010), but it may be a valid taxon considering the local area endemism of the Massif du Panié and that no other Taophilas. str. had been reported in the area. Until the validity of the species is settled, it is appropriate to propose the following transfer: Taophila mandjeliae (Jolivet, Verma & Mille, 2010), comb. n.