Mecodema jacinda Seldon & Buckley 2019, sp. n.

Mecodema jacinda sp. n.

Figure 32.

Diagnosis: Differing from all other North Island Mecodema species by: 1, vertex smooth, vertexal groove defined by a few obsolescent punctures; 2, the pronotal carina broad the entire length with 8–12 setae each side; 3, interval 7 strongly convex in apical ⅓ (very distinctive); 4, the shape of the apical portion of the penis lobe (Fig. 32 PL).

Description: Length 29–36 mm, pronotal width 7.9–10.2 mm, elytral width 9.1–11.6 mm. Colour of entire body matte to glossy black (especially pronotum).

Head: Broad and flat (Fig. 14A). Vertex with very fine (almost indistinct) lines forming an isodiametric pattern, especially laterally; vertexal groove broad and slightly impressed, defined by scattered obsolescent punctures (Fig. 32); small supraorbital puncture bearing 3–5 setae; 3–4 slightly impressed supraorbital grooves; frons (Fig. 9) with a large and shallow depression each side of midline, indistinctly grooved antero-laterally; frontoclypeal suture well-defined, medially convex, tentorial pits small; anterior area of clypeus with deep grooves each side and medially, 1 large setose puncture each side bearing 2 setae, medial setose puncture large bearing 1 seta. Labrum rectangular, anterior edge straight, very slightly emarginated with 2 proximate central setae, 2 setae each side evenly spaced. Mentum lobes rounded (Fig. 12F), median process very short and broad, moderately angled upward (30°), moderately indentate (Fig. 12B); mentum setae absent. Submentum sclerite (Fig. 8) constriction broad with 6–8 setae evenly spaced. Stipes with 2 basal setae. Gula pits large, suture well-defined, gula flat and smooth. Gena with fine transverse wrinkles across entire area.

Prothorax: Prothoracic carina broad the entire length, crenulations absent with 8–12 setae each side (Fig. 32), extended beyond anterior angle; posterior lateral sinuation indistinctly carinate, parallel; pronotum broad and laterally deflected, overall shape cordate (Fig. 32); midline slightly impressed, anterior medial triangular impression and posterior medial diamond-shaped impression present, disc with very fine transverse wrinkles (Fig. 32) and a small shallow depression each side (midway); pronotal foveae broad and deep; anterior edge slightly inwardly curved, posterior edge straight. Prosternum (Fig. 2) flat with a series of transverse broad and shallow grooves; proepisternum without microsculpture. Procoxal setae absent; protibia distally expanded and shovel-like (Fig. 10B).

Elytra: Broad and moderately deflected laterally; humeral angle evenly convex (Fig. 6B); basal margin sharply curved (truncated by intervals 1 and 2 extending to scutellum) and bevelled to base; lateral margin narrow medially but broadened in anterior ⅓ and posterior ⅓, extended beyond humeral angle; humerus with 3–4 setose punctures along angle (Fig. 32); suture slightly impressed; striae 1–4 impressed as lines (punctures obsolescent); striae 5–8 with punctures becoming more visible, all small and regularly spaced; intervals 1–4 weakly convex, intervals 5–9 moderately convex, interval 7 strongly convex in apical ⅓ (very distinctive); interval microsculpture present as fine transverse lines; 7 th strial setal pattern with 2–3 setose punctures in anterior ½, 5–6 setose punctures in posterior ½, setose punctures large.

Ventral surface: Mesepisternum sparsely punctured; mesosternum with tranverse grooves, metepisternum (Fig. 2) without microsculpture; setose punctures present on mesecoxa (2) can have multiple setae, and metacoxa (2). All abdominal ventrites (Fig. 2) finely lineate; ventrites 3–5 with 1 setose puncture each side of midline; ventrite 6 setae present: ♂ with 1 seta each side at junction of straight apical edge and curve anterad, ♀ with 2 setae each side between straight apical edge; lateral foveae absent. Anterior metaventrite process a short triangle with broad and moderately defined carina the entire length.

Male genitalia: Apical portion of penis lobe asymmetrically hooked and width narrow (vertically), ventral process formed by a long curve downward from shaft to form a bluntly rounded point, pushed forward of vertical axis (LV) (Fig. 3), apex with a flattened curve upward to form the dorsal process, that is a very bluntly rounded, short and squat hook with a gentle curve to shaft (Fig. 32 PL); shaft of penis lobe with a slight deflection to right of vertical axis VV (Fig. 15C); shaft moderately curved to right the entire lenght (VV), penis lobe shaft narrow for apical ⅓ then gradually broadened to base; overall length of penis lobe moderately curved ventrally (LV) (Fig. 16B). Structures of the endophallus (Fig. 4): lateral form of the apex of the central spicule pointed; dorsal form of the apex of the central spicule greatly expanded with projection; setal (scales) coverage of the apical plate extensive (76–100%); size of left setose flange small; size of right setose flange absent. Left paramere basal lobe narrow and rectangular with a moderate dorsal hump, that forms a moderate (45°) slope to arm; arm long and narrow; terminal lobe broader than arm with a apical tuft of sparse short setae (Fig. 32 LP); comb of long setae from mid-arm to junction of basal lobe; setae extended along apical ⅓ of ventral edge; ventral edge straight. Right paramere a very narrow triangle that narrows towards terminal end, a double row of long setae extended along apical ½ of ventral edge (Fig. 32 RP).

Female genitalia: Basal gonocoxite 1 short and broad apically, ventral surface covered in deep grooves, internal dorso-lateral carina with 3 setae. Gonocoxite 2 with a broadly rounded apex, shortened with a broad base. Ramus (Fig. 5) long and relatively broad.

Comments: The largest of the three Mecodema species found at Maungatautari E.R., this species is relatively abundantly collected in pitfall traps and by log rolling.

Distribution: New Zealand, North Island, Waikato, Maungatautari Ecological Reserve.

Holotype: NZAC male labelled. NEW ZEALAND WO, Maungatautari E.R., PTs, Jan–Feb 2009, C. Watts, Landcare / HOLOTYPE Mecodema jacinda n. sp. design. DS Seldon, TR Buckley 2018 [red label].

Paratypes: 1, NEW ZEALAND WO, Maungatautari E.R., PTs, 20 Nov–17 Dec 2008, C. Watts, Landcare (LUNZ); 4, NEW ZEALAND WO, Maungatautari E.R., PTs, 17 Dec 2008 – 18 Jan 2009, C. Watts, Landcare (AMNZ); 3, 1♀, NEW ZEALAND WO, Maungatautari E.R., PTs, 18 Jan–17 Feb 2009, C. Watts, Landcare (NZAC); 1♂, 1♀, NEW ZEALAND WO, Maungatautari E.R., PTs, 18 Jan–17 Feb 2009, C. Watts, Landcare (MONZ).

Etymology: Mecodema jacinda is named to honour Jacinda Ardern, leader of the Labour Party.