Mecodema chaiup Seldon, 2015.

Figure 22.

Diagnosis: Distinguished from other North Island Mecodema by: 1, the narrow elytra (narrower than the pronotum at the widest point); 2, the distinct asetose punctures in a confused pattern that are irregular in size and shape (Fig. 22).

Description: Length 31 mm, pronotal width 8.5 mm, elytral width 6.5 mm. Colour of entire body matte black, except femur and tibiae are dark reddish-brown.

Head: Broad and flat (Fig. 14A). Vertex (Fig. 9) with very fine lines forming an isodiametric pattern; vertexal groove defined by enlarged frons, groove broadened laterally; small supraorbital puncture bearing 4–5 setae; 4 shallow supraorbital grooves anterad eyes; large cuticular depressions latero-posterad eye and supraorbital puncture; frons with small circular depressions laterally within a larger frontal depression; frontoclypeal suture narrow and defined with tentorial pits indistinct within a larger depression; anterior area of clypeus with 3 narrow grooves, central groove with setose puncture bearing 1 seta, 1 setose puncture each side bearing 3 setae. Labrum lobate, anterior edge moderately emarginated with 2 proximate central setae, 2 setae each side evenly spaced. Mentum lobes rounded (Fig. 12F), median process very broad and long, apex distinctly angled upward (60°), distinctly indentate (Fig. 12A); mentum setae absent. Submentum sclerite (Fig. 8) constriction broad with 6 setae, with a broad gap medially. Stipes with 3 basal setae. Gula pits narrow and deep, suture well-defined, gula flat with very fine transverse wrinkles. Gena with wrinkled isodiametric pattern across the entire area.

Prothorax: Prothoracic carina broad the entire length, slightly crenulated in anterior portion with 8–12 setae each side, extended beyond humeral angle; posterior lateral sinuation indistinctly carinate, parallel; pronotal lateral margin broad in anterior half, disc flattened anteriorly, anterior lateral margin of pronotum angled sharply posterad (Fig. 22), overall shape cordate; midline well-defined, anterior medial and posterior medial diamond-shaped impressions present, disc with transverse lines across entire area; pronotal foveae (Fig. 11) very broad and shallow; anterior edge slightly inwardly curved, posterior edge strongly curved each side, inwardly curved medially. Prosternum concave with light transverse wrinkles present; proepisternum (Fig. 2) sparsely micropunctate. Procoxal setae absent; protibia distally expanded and shovel-like (Fig. 10B).

Elytra: Broad and flattened but narrower than pronotum (at broadest point), posterior end of elytra steep to apex; humeral angle evenly convex (Fig. 6B); basal margin slightly curved and gently sloped to base, interval 1 extended to scutellum; lateral carina narrow the entire length, extended to humeral angle; humerus with 3–4 setose punctures proximate the angle then 1 spaced equally between umbilical series (Fig. 22); suture well-defined with sutural intervals clearly defined and microsculpture absent; intervals 2–6 indistinct but contributing to confused pattern of striae; asetose punctures very irregular in size and shape; 7 th strial (Fig. 1) setal pattern with 4 setose punctures in anterior ½, 3 setose punctures in posterior ½ to apex, setose punctures large.

Ventral surface: Mesepisternum micropunctate; metepisternum without microsculpture; setose punctures present on mesocoxae (2) and metacoxae (2). Abdominal ventrites 1–5 (Fig. 2) finely lineate, ventrites 1 and 2 micropunctate; ventrites 3–5 with 1 setose puncture each side of midline; lateral foveae absent; ventrite 6 setae present: ♂ with 1 seta each side distantly spaced at opposite ends of straight apical edge and junction of curve anterad (no ♀ specimen available). Anterior metaventrite process (Fig. 2) triangular with a well-defined and broad carina the entire length.

Male genitalia: Apical portion of penis lobe asymmetrically hooked, without deflection to right (VV); dorsal process rounded and apically flattened i.e., hammer-like in shape, ventral process shorter and more rounded (Fig. 22 PL), pushed forward so not perpendicular to shaft (Fig. 3); penis lobe shaft equally narrow the entire length, ventral edge distinctly curved to right (VV), overall length of the penis lobe distinctly curved ventrally (LV) (Fig. 16C). Structures of the endophallus (Fig. 4): lateral form of the apex of the central spicule flattened; dorsal form of the apex of the central spicule greatly expanded with a projection; setal (scales) coverage of the apical plate moderate (26–75%); left setose flange small; right setose flange absent. Left paramere basal lobe rectangular, broadened and humped dorsally forming a steep anterior angle (60°) to arm (Fig. 22 LP), ventral edge very straight; arm angled downward, ventral edge curved upward to form short narrow arm; terminal lobe rounded, broader than arm with a long tuft of setae at apex; setae extended along apical ½ of ventral edge, very sparse on arm. Right paramere long, narrow and triangular with apical ⅓ curved inwardly toward penis lobe, numerous long setae extended along apical ½ of ventral edge (Fig. 22 RP).

Female genitalia: no female specimen available.

Comments. The only specimen of this species was collected in Mohi Bush Scenic Reserve, Maraetotara Plateau in January 2008. Since then there has been a number of extensive, but unsuccessful pitfall trapping events to collect further specimens.

Distribution. New Zealand, North Island, Hawke’s Bay, Maraetotara Plateau, Mohi Bush Scenic Reserve.

Holotype. NZAC male labelled. NEW ZEALAND, HB, Mohi Bush Scenic Reserve, 2 January 2008, ♂ D.S. Seldon & C.P. Martin, S39°51 24.5" E176°53 56.2" / HOLOTYPE Mecodema chaiup sp. nov. Design. by D.S. Seldon 2014 [red label] / NZAC04095692 (see Seldon 2015).