Mecodema moniliferum Bates, 1867, comb. n.

Figure 39.

Metaglymma monilifer Bates, 1867 (Canterbury) .

Metaglymma rugipenne Broun, 1893a (Ashburton, MC), synonymised by Britton 1949.

Metaglymma minor Broun, 1905 (north Canterbury), synonymised by Britton 1949.

Diagnosis: Distinguished from other Mecodema species by having: 1, ventrites 4–5 bearing numerous setose punctures; 2, elytral striae defined anteriorly and laterally by large, irregularly spaced asetose punctures (Fig. 39); 3, shape of basal lobe and setal distribution along ventral edge of left paramere (Fig. 39 LP).

Description: Length 14.6–19.5 mm, pronotal width 4.2–6.2 mm, elytral width 5.1–7.1 mm. Colour of entire body matte reddish-brown to matte black.

Head: Narrow and flat (Fig. 14C). Vertex (Fig. 9) smooth; vertexal groove narrow laterally, indistinct medially; large supraorbital puncture bearing 4–5 setae; 1 shallow supraorbital groove; frons with a small rounded depression each side of midline; frontoclypeal suture a distinctly narrow, straight groove between small tentorial pits; anterior area of clypeus smooth, 1 setose puncture each side bearing 1 seta (Fig. 39). Labrum rounded, anterior edge outwardly curved with 2 proximate central setae, 2 setae each side evenly spaced. Mentum lobes squared (Fig. 12G), mentum process long and broad, slightly angled upward (15°), strongly indentate (Fig. 12A); mentum setae present. Submentum sclerite constriction narrow with 6 setae, large gap medially, evenly distributed laterally. Stipes with 2 basal setae. Gula pits large, suture poorly defined, gula flat with transverse lines. Gena (Fig. 2) with fine wrinkles across entire area.

Prothorax: Prothoracic carina broad the entire length, moderately crenulated with 5–8 setae each side (Fig. 39), extended to anterior angle; posterior lateral sinuation indistinctly carinate, slightly angled inward; pronotum broad and moderately deflected laterally, overall shape rounded; midline indistinctly impressed, posterior medial diamond-shaped impression only, disc with very fine wrinkles laterally (Fig. 39); pronotal foveae broad and shallow; anterior edge slightly inwardly curved, posterior edge curved inwardly medially. Prosternum flat with very fine lines; proepisternum without microsculpture. Procoxal setae (Fig. 2) absent; protibia distally expanded and shovel-like (Fig. 10B).

Elytra: Broad and moderately deflected, length truncated and steeply sloped to apex; humeral angle evenly convex (Fig. 6B); basal margin distinctly curved and bevelled to base, interval 1 extended to margin; lateral carina narrow the entire length, extended to humeral angle; humerus with 4–6 setose punctures within angle (Fig. 39); suture impressed but no more so than striae; striae with small, regularly spaced, asetose punctures, striae 1–4 with obsolescent punctures, increasingly defined laterally (Fig. 39); intervals 1–6 weakly convex, intervals 7–9 moderately convex; interval microsculpture present as transverse lines; 7 th strial setal pattern with 2–3 setose punctures in anterior ½, 5–6 setose punctures in posterior ½, setose punctures small.

Ventral surface: Mesepisternum (Fig. 2) with a few rugose wrinkles; metepisternum without microsculpture; setose punctures present on mesocoxae (1) and metacoxae (2). All abdominal ventrites finely lineate laterally (sparse); ventrite 3 with 1–2 setose punctures each side of midline, ventrite 4 with 3–4 setose punctures each side of midline, ventrite 5 with 6–8 setose punctures each side of midline; ventrite 6 setae present: ♂ with 2 setose punctures at junction of straight apical edge and curve anterad, ♀ with 2 setose punctures, distantly spaced at junction of bluntly rounded apical edge and curve anterad; ventrites foveate laterally. Anterior metaventrite process (Fig. 2) a long narrow triangle without a carina.

Male genitalia: Apical portion of penis lobe asymmetrically rounded with a distinct deflection to right of vertical axis (VV) (Fig. 15A), apex curve flat and slightly forward of vertical axis (Fig. 39 PL); shaft of penis lobe broad and short with curve of ventral edge to left (VV); overall length of penis lobe without curve ventrally (straight). Structures of the endophallus (Fig. 4): lateral form of the apex of the central spicule rounded; dorsal form of the apex of the central spicule short and narrow; setal (scales) coverage of the apical plate sparse (1–25%); size of left setose flange small; size of right setose flange large. Left paramere basal lobe ovate, dorsal hump absent with short slope to arm; arm long and narrow; terminal lobe not defined, apical tuft of long setae (Fig. 39 LP); very short setae along arm ventral edge, long setae along basal lobe ventral edge; ventral edge slightly curved, setae along entire length. Right paramere long and narrowly rectangular, slightly narrowed to apex, setae extended along apical ¾ of ventral edge (Fig. 39 RP).

Female genitalia: Basal gonocoxite 1 short and broad, ventral surface with a few rugose wrinkles; internal dorso-lateral carina with 2 setae. Gonocoxite 2 short and broad, ovate in shape; 1 short seta at base near junction with gonocoxite 1 (ventral surface). Ramus (Fig. 5) long and broad.

Comments: Although Mecodema moniliferum is only found in the braided river systems of the South Island, analyses show that it nested within the monophyletic curvidens species group.

Distribution: New Zealand, South Island, Kaikoura (KA), north to south Canterbury (MC, NC, SC).

Holotype: not viewed. Type in the R. Oberthür Collection at Rennes, Muséum of National d’Histoire Naturelle, France. Type locality near Christchurch; collected by Mr Fereday (Britton, 1949).

Material examined: 1♀, Moyunau I. 1–5.xii.67 / Pit traps A. Whittaker / Metaglymma monilifer Bates Det. J.I. Townsend 18.I.68 [hw] (NZAC) ; 2, Waikuku Beach, Rangiora, 2 Dec 1941, D. Spiller [hw] (NZAC); 1♂, 1♀ [card mounted], Mt Algidus, 2000’, 2– 13.12.59, J.I.Townsend (NZAC) .