Callistomorphus turbidus, 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 turbidus sp. n. Figs 5, 11, 21, 30, 39, 48, 57, 66, 75, 84, 93, 100, 107, 114, 121

Diagnosis.

Easy to distinguish by combination of several features: apical and basal margin of pronotum slightly concave, apical margin in lateral view distinctly protruding towards head; rostrum relatively short and stout, less than 3 × as long as maximum width apically; strongly curved; penis strongly upwards before two-thirds of length; pygidium apically with distinct depression in ventral view; lateral margin of pygidium in ventral view irregular.

Description.

Body length (lb) - 8.50 mm.

Body colour and vestiture (Fig. 21). Generally dark brown. Indistinct, paler, stripe from scutellum to base of medial tubercles on third intervals; oblique paler stripe behind medial tubercles reaching paler spot on side of elytra. Pronotum with two, indistinct, lighter, narrow, longitudinal stripes of scales. Head and rostrum covered with paler scales. Tibiae orange, distinctly paler than dark brown femora. Ventrites dark brown with bundle of paler scales on 3rd and 4th ventrites.

Head (Figs 5, 66, 75, 84). Slightly longer than wide (hw/hl ♂: 0.92). Eyes convex with maximum width before middle; shorter than half length of head (eyl/hl ♂: 0.42); not protruding above margin of head in lateral view. Frons slightly wider than double width of eyes. Rostrum slightly longer then pronotum (rl/pl ♂: 1.11); strongly curved and stout (rl/arw ♂: 2.86); longitudinal carina on rostrum very distinct, sharp and polished from base to antennal insertion. Scape shorter than rostrum (scl/rl ♂: 0.75). First funicle segment short, only 1.2 × as long as 2nd; 3rd 0.6 × as 2nd; from 3rd to 7th with similar length; club as long as last four funicle segment combined; setae on antennomeres distinct, elongate, moderately protruding.

Pronotum (Figs 48, 57). Slightly wider than long (bpw/pl ♂: 1.17). Base 1.24 × as wide as apical margin (bpw/apw); apical margin concave with weakly developed tubercles, only on apical angles tubercles distinct and protruding; in lateral view apical margin protruding towards head; basal margin slightly, but visibly, concave medially; basal angles, in dorsal view, lying clearly below middle part of basal margin. Medial tubercles weakly developed, obtuse; in lateral view slightly protruding above margin of pronotum. Width of medial constriction in relation to apical and basal margin in male: mpw/apw = 0.59; mpw/bpw = 0. 48.

Elytra (Figs 30, 39). Relatively short (el/bew ♂: 1.47); slightly narrowed behind humeral angles; posterior calli developed, protruding beyond outline of elytra in dorsal view. Surface with very rough sculpture; striae composed of subcircular, shallow punctures; surface bordering striae and intervals indistinct, especially on basal half in front of medial tubercles. Apically striae evanescent, only as shallow punctures. Medial tubercles distinct, lower than width at base. Scutellum slightly longer than wide.

Abdomen (Figs 93, 107). Slightly longer than wide (al/aw ♂: 1.06). Last ventrite 2.13 × wider than long (lvw/lvl); apical margin sharp; medially on apical portion wide, shallow cavity. Pygidium with a specific shape; apically, in ventral view, with deep cavity.

Male terminalia (Figs 100, 107, 114 121). Penis body distinctly longer than apodemes; base fully sclerotised; from base slightly dilated, maximum width before midlength; before two-thirds of length distinctly narrowed, then subparallel to widely rounded apex; distinctly curved in lateral view, upward before two-thirds of length. Internal sac without any visible structures or sclerites. Parameroid lobes and tegminal apodeme with similar length; divided beyond middle of length. Spiculum gastrale Y-shaped; hemisternites fused with base of spiculum. Hemisternites of sternite VIII elongate, clavate.

Female - unknown

Measurements. ♂: al 3.40, apw 1.70, arw 0.70, aw 3.20, bew 3.80, bpw 2.10, el 5.60, eyl 0.50, frw 0.55, hl 1.20, hw 1.10, lb 8.50, lvl 0.80, lvw 1.70, mpw 1.00, pl 1.80, rl 2.00, scl 1.50.

Type material.

Holotype, ♂ (here designated) - New Caledonia (N); 20°24'00.3"S, 164°31'40.4"E; Mt. Mandjélla 700-780 m; montane rainforest; 20.11.2008, leg. M. Wanat. (MNHN).

Etymology.

This epithet is derived from the Latin adjective " turbidus " (confused, impatient) and refers to my feelings after I wasted too much time trying to create any suitable name for this creature.

Remarks.

By the short, distinctly curved rostrum, small size and very characteristic male terminalia (unique form of pygidium, strongly upwardly-directed penis body in lateral view), this species is easy to distinguish within the genus. A female is unknown but may be easily to distinguished based on the description presented above.