Callistomorphus gibbus, Mazur, Milosz Adam, 2019

Mazur, Milosz Adam, 2019, Redescription of the forgotten New Caledonian weevil genus Callistomorphus Perroud, 1865 (Coleoptera, Curculionidae, Eugnomini) with descriptions of eight new species, ZooKeys 821, pp. 45-83 : 45

Callistomorphus gibbus sp. n. Figs 6, 15, 24, 33, 42, 51, 60, 69, 78, 87, 96, 103, 110, 117

Diagnosis.

This species can be distinguished from other members of the genus by the following suite of characters: apical margin of pronotum concave in dorsal view, base sinuate, protruding towards elongate scutellum. Rostrum distinctly bent in middle of length.

Description.

Body length (lb) - 7.90-9.60 mm.

Body colour and vestiture (Fig. 15). Generally dark brown with various, irregular spots of different shades of brown. Legs in some specimens with mottled coloration, from whitish to variable shades of orange and almost black. Tibiae generally paler, more or less orange. Pronotum sometimes with darker spots near base, medially and with pair of narrow, oblique stripes of white-yellow scales from hind angles to middle of length.

Head (Figs 6, 60, 69, 78). Subquadrate to wider than long (♂: hw/hl = 1.00-1.20). Frons wider than double width of eye. Eyes approximately as long as half of length (♂: eyl/hl = 0.45-0.55), not protruding above margin of head in lateral view, regularly rounded. Rostrum as long as pronotum or little shorter (♂: rl/pl = 1.00-1.12), from 3.00 to 3.17 × as long as maximum width (rl/arw); with polished, sharp longitudinal carina on entire length; in lateral view distinctly curved medially. Scape shorter than rostrum (♂: scl/rl = 0.82-0.90). First funicle segment slightly longer than 2nd, 3rd almost as half-length of 2nd, antennomeres from 4th to 7th with similar length, little longer than wide. Club slightly as long as last four funicle segment combined, ca 1.8 × as long as wide.

Pronotum (Figs 6, 42, 51). Wider than long (♂: bpw/pl = 1.06-1.15); base 1.26-1.47 × as wide as apical margin (bpw/apw); apical margin distinctly, widely concave with small tubercles; apical angles with rounded, distinct tubercle; in lateral view apical margin protruding towards head. Medial tubercle on pronotal disc well developed, divided into two, strongly protruding appendices. Width of medial constriction in relation to apical and basal margin in male: mpw/apw = 0.63-0.71, mpw/bpw = 0.48-0.50.

Elytra (Figs 24, 33). Approximately 1.5 × as long as its width (♂: el/bew = 1.48-1.55); slightly narrowed from humeral calli to apical part. Medial tubercles distinct, elongate; elytral disc with numerous, small acuminate tubercles; tubercles on 7th intervals easily visible, protruding from outline of elytra in dorsal view. Striae with suboval, deep punctures; surface of elytral disc distinctly rugose. Scutellum triangular, as long as wide at base.

Abdomen (Figs 87, 103). In male from 0.94 to 1.20 × as long as wide (al/aw). Male pygidium as in Fig. 87. Last ventrite 2.14-2.37 × wider than long (lvw/lvl).

Male terminalia (Figs 96, 110, 117). Penis body slightly longer than apodemes; from base to apical part almost subparallel, apically slightly narrowed to rounded apex; basal part sclerotised, except medial part; distinctly, regularly curved in lateral view, apices thin and distinctly upturned. Internal sac without any structure or sclerites. Parameroid lobes of tegmen thin, distinctly shorter than apodeme, divided almost to base. Tegminal apodeme apically extended. Spiculum gastrale robust, similar to C. fundatus sp. nov; hemisternites fused with base of spiculum.

Female - unknown.

Measurements. ♂: al 3.20-3.60, apw, 1.40-1.90, arw 0.60-0.70, aw 2.90-3.50, bew 3.40-4.20, bpw 1.80-2.50, el 5.30-6.50, eyl 0.50-0.60, frw 0.50-0.60, hl 0.90-1.10, hw 1.00-1.20, lb 7.90-9.60, lvl 0.70-0.85, lvw 1.50-2.00, mpw 0.90-1.20, pl 1.70-2.20, rl 1.80-2.20, scl 1.60-1.80.

Type material.

Holotype, ♂ (here designated) - New Caledonia (N); 21°08'56.0"S, 165°19'20.9"E; Aoupinié (refuge), 400 m, at light; 25.11.2006; leg. M. Wanat (MNHN).

Paratypes: 1♂ - New Caledonia (N); 21°08.9'S, 165°19.4'E; Aoupinié (refuge), 18.01.2007, 420 m, at light, leg. M. Wanat & R. Dobosz (MNHW).

1♂ - New Caledonia (N), 20°57.2'S, 165°17.5'E, Pic d’Amoa, 360 m, 14.01.2007, forest at light, leg. M. Wanat & R. Dobosz (MNHW).

1♂ - New Caledonia (S), 22°01'54.5"S, 166°28'02.6"E, Mt. Ouin Rd, 900 m, 0-0.5 km N of Dzumac jct, 5.12.2010, night coll., leg. M. Wanat & R. Dobosz (MNHW).

Etymology.

This epithet is the Latin noun " gibbus " (protuberance, hump) and refers to a pair of large tubercles on elytra. A noun in apposition.

Remarks.

The shape of pronotum together with the lateral profile of the rostrum are characteristic for this new species. The terminalia are quite similar to C. fundatus sp. n. but differ in the shape of the apex of the penis (in dorsal view more rounded, in lateral view more upwardly directed in C. gibbus sp. n.). One small specimen was quite similar to C. turbidus sp. n. in bodily proportions, but distinctly different in the shape of the pronotum, rostrum length and form of terminal structures.