Trigonops samuelsoni, Kuschel, 2008

Kuschel, Guillermo, 2008, Curculionoidea (weevils) of New Caledonia and Vanuatu: Basal families and some Curculionidae, Mémoires du Muséum national d'Histoire naturelle 197, pp. 99-250 : 170-171

Trigonops samuelsoni n. sp.

Fig. 68

DESCRIPTION. — Black in fully mature specimens, femora and often part of tibiae reddish. Scales dull whitish or grey, usually faintly blue or green, smooth under 50 x, not dense, leaving derm partly exposed, denser on sides of prothorax, humeral area, suture and upper part of declivity, rather bare on either side at elytral midlength flanking a major swelling by interstria 6, this subglabrous area showing as a distinct dark macula. Setae fine, recumbent.

Head and forehead finely rugose. Eyes strongly convex, but distinctly less than hemisphericala, set ooff from forehead by a fine sulcus. Rostrum as long as wide in female, marginally longer in male, parallel-sided to pterygial area where slightly wider; separated from forehead by a deep, right-angled, inverted V-shaped sulcus with straight sides, these passing downwards against front margin of eyes; apical declivity moderately steep, sparsely squamose, without distinct knob above scrobes, with a fine median acrina or smooth line; dorsal surface at scrobal indentation a little less than one-half (0.43) the width of rostrum below this point, about one-half of width of forehead between eyes. Scape gently, gradually widening from base to apex, not compressed, coarsely sculptured with confluent punctation, with sparse scales and appressed setae; funicle lacking scales, first two segments subequal in length, other segments shorter but distinctly longer than wide; club fusiform, as long as preceding three segments of funicle.

Prothorax variable, as long as wide or up to 1.12 x wider than long, truncate at base, here with a narrow lower rim, diverging slightly sinuously or in straight line to a rounded widest part, longitudinally flat or weakly convex, disc slightly asperate, granulate-punctate, granules and puncta subdued.

Elytra about 1.45 x wider than prothorax, 1.33 x longer than combined width in male, 1.43 x so in female, gently concavely curved at base, widening to basal one-quarter, converging from around middle to a rather narrowly rounded apex, in lateral view flat on median area as far as declivity in male, gently convex in female, with apex not curved downwards; striae just punctate, as wide as interstriae, 10th with only slightly coarser puncta up to hind coxa, then gently approaching 9th; each elytron with a large swelling just beyond middle involving area between striae 3 and 8, with interstria 6 topping the raised area, this swelling distinctly more prominent in male; elytral dorsum depressed between swellings; granules present in striae and on some interstriae but very small under 50 x; suture in female on top of declivity lacking tuft of setae.

Mesosternal process much wider than long, gently sloping, squamose. Mesepimeral upper corner against head of metepisternum protruding to a distinct tubercle; metepisternal suture absent or obsolescent; metasternum and ventrite 1 broadly impressed, densely punctate, with short erect hairs in male, flat, with nearly recumbent hairs in female, ventrite 2 flat in male, convex in female; ventrite 5 flat in male, impressed in female.

Male: aedeagus (incl. apodemes) 1.5 x longer than abdomen, extending well into thoracic lumen; body a littsle over 3 x longer than wide in the middle, distinctly widening basad, parallel-sided in the middle, tapering apicad from ostium to a blunt point, apex beyond ostium about as long as wide; dorsal surface well-pigmented on basal half, paler on apical half. Internal sac very long, exposed part about 1.2 x longer than whole aedeagus; flagellum approximately 1.3 x longer than aedeagal body, well-pigmented, wider on basal half, becoming threat-like at apex.

Female: not dissected.

Length: 5.5-7.5 mm.

TYPE MATERIAL. — Holotype male, 6.4 x 3.2 mm, data as above , BPBM. Paratypes with BPBM, NZAC .

MATERIAL EXAMINED. — Vanuatu. Vanua Lava : 4 males, 2 females, Sola to Chelva River, 0-20 m, 16.IX.1979, G. M. Nishida, G. A. Samuelson. 6 specimens .

ETYMOLOGY. — The species is dedicated to G. A. (Alan) Samuelson for collecting specimens of the species, and for making the collections of Curculionidae of the Bernice P. Bishop Museum from New Caledonia and Vanuatu available for this report on the fauna of the islands.

REMARKS. — T. samuelsoni is distinguished by its more elongate habitus, a less dense scaling, and a large dark macule flanking the elytral dorsal swellings.