Callistomorphus minimus, 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 minimus sp. n. Figs 17, 26, 35, 44, 53, 62, 71, 80, 89, 124, 129, 137, 142

Diagnosis.

The smallest member of the genus with several characteristic features. Eyes strongly convex, distinctly protruding above margin of head in lateral view. Pronotum distinctly narrowed from base to approximately three-quarters of length, apically sides only slightly expanded towards anterior margin; dorsal surface glabrous, medially only with small, obtuse tubercle. Elytra slender, elongate; without distinct medial tubercles, only with single, small tubercles on intervals. Apical part of elytra and sides of pronotum dark brown, in contrast to colour of the rest parts of body.

Description.

Body length (lb) - 7.20 mm.

Body colour and vestiture (Fig. 17). Body covered almost entirely with yellowish scales. Rostrum brown. Antennae light brown. Lateral part of pronotum dark brown; base of pronotum in dorsal view with two, short, brownish stripes reaching to one-fifth of its length; between them small, brown spot. Elytra uniformly yellowish except: brownish apical angles ahead of humerus; base of intervals 3-5; indistinct, suboval darker spot from 1st to 3rd intervals before midlength. Apical part of elytra from four-fifth of length dark brown. Scutellum light brown. Mesepimeron, mesanepisternum and mesoventrite brown; metanepisternum together with metaventrite yellowish as most part of elytra. Legs uniformly yellowish.

Head (Figs 62, 71, 80). Slightly wider than long (hw/hl ♀: 1.17). Frons narrower than double width of eye; longitudinal carina between eyes distinct, surface between concave. Eyes strongly convex, circular, slightly longer than half length of head (eyl/hl ♀: 0.56), distinctly protruding above margin of head in lateral view. Rostrum longer than pronotum (rl/pl ♀: 1.20), 3.40 × as long as maximum width at apex (rl/arw); longitudinal carina indistinct, polished only from antennal insertion to apex. Scape shorter than rostrum (scl/rl ♀: 0.76). First funicle segment ca 1.2 × as long as 2nd and 2 × as long as 3rd; antennomeres 4th and 5th slightly longer than wide; last two as long as wide. Club suboval, 2 × as long as wide, as long as last four funicle segment combined.

Pronotum (Figs 44, 53). Shorter than width at base (bpw/pl ♀: 1.21); 1.70 × as wide as apical margin (bpw/apw). Apical margin straight in dorsal view, not expanded, without tubercles; in lateral view anteriorly almost straight, then converging towards base; anterior transverse groove deeply concave. Medial tubercle not separate, only as slightly convex, single tubercle.

Elytra (Figs 26, 35). Elongate (el/bew ♀: 1.68). Regularly narrowed from base to apical part; posterior calli weakly developed, not protruding beyond outline of elytral in dorsal view. Surface of striae and intervals not visible due to very dense scales. Medial tubercles absent, on striae only single, small tubercles completely covered with scales. Scutellum slightly longer than wide, slightly protruding above margin of elytra in lateral view.

Abdomen (Figs 89, 129). Slightly longer than wide (al/aw 1.15). Second ventrite with sparse, erect, strongly elongate scales, clearly visible on the background of adjacent, shorter scales. Last ventrite 2.60 × wider than long (lv/lvl). Pygidium as in Fig. 129.

Female terminalia (Figs 124, 137, 142). Sternite VIII distinctly expanded apically with characteristic shape. Abdominal tergite VIII distinctly narrowed apically with rounded apex; sides with strongly elongate setae. Spermatheca lost in dissection. Ovipositor slender, almost straight; gonocoxite elongate; vagina well sclerotised.

Male - unknown

Measurements. ♀: al 3.00, apw 1.00, arw 0.50, aw 2.60, bew 2.85, bpw 1.70, el 4.80, eyl 0.50, frw 0.40, hl 0.80, hw 1.05, lb 7.40, lvl 0.50, lvw 1.30, mpw 0.90, pl 1.40, rl 1.70, scl 1.30.

Type material.

Holotype, ♀ (here designated) - New Caledonia (S); 21°37'17.8"S, 165°52'38.6"E; Plateau de Dogny, 9.11.2010, 960 m; leg. R. Ruta (MNHN).

Etymology.

This epithet is the Latin adjective " minimus " (small, little), the new species is the smallest member of the genus.

Remarks.

C. minimus sp. n. is a very characteristic species. It is easy to distinguish from other members of the genus by small size, shape of pronotum (not extended apically), reduced tubercles on elytra and pronotum and contrasting coloration of the body.