Mecodema ngaitahuhu Seldon & Buckley 2019, sp. n.
Creators: name: Seldon, David S.
name: Buckley, Thomas R.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Mecodema
Mecodema ngaitahuhu

description: Mecodema ngaitahuhu sp. n.
Figure 41.
Diagnosis: Distinguished from other North Island Mecodema species because: 1, the prothoracic carina is smooth with 7–11 setae each side; 2, elytral interval 6 is truncated, i.e. it terminates before meeting the basal margin; 3, distinct shape of the apical portion of the penis lobe (Fig. 41 PL); 4, form of the left paramere terminal lobe and ventral edge setae (Fig. 41 LP).
Description: Length 26–32 mm, pronotal width 7.5–9.5 mm, elytral width 8.6–10.6 mm. Colour of entire body matte to glossy black dorsal, ventrally may be dark reddish-brown, including coxae and legs.
Head: Broad and flat (Fig. 14A). Vertex smooth; vertexal groove shallow, defined laterally by indentations (obsolescent punctures); large supraorbital puncture bearing 5 setae (Fig. 41); 2–3 supraorbital grooves poorly defined mesad eyes; frons smooth; frontoclypeal suture indistinct, tentorial pits very small; anterior clypeus with well-defined grooves, 1 setose puncture each side bearing 1–2 setae (may have central setose puncture bearing 1 seta). Labrum lobate, anterior edge strongly emarginated with 2 proximate central setae, 2 setae each side evenly spaced. Mentum lobes rounded (Fig. 12F), mentum process broad and very broad, slightly angled upward (15°), distinctly indentate (Fig. 12A); mentum setae variably present or absent. Submentum sclerite (Fig. 8) constriction narrow with 6 setose punctures, wide gap medially, then setae evenly spaced. Stipes with 2 basal setae. Gula pits small within defined suture, gula flat and smooth. Gena with fine lines forming an isodiametric pattern across entire area.
Prothorax: Prothoracic carina broad at shoulder, narrowed to sinuation, smooth to slightly crenulated with 7–11 setae each side (Fig. 41), extended beyond anterior angle; posterior sinuation indistinctly carinate, parallel; pronotum broad and flattened but deflected laterally, anterior lateral margin rounded, overall shape cordate; midline well-defined, anterior medial and posterior medial diamond-shaped impressions present, disc entirely covered with fine transverse lines (Fig. 41); pronotal foveae broad and shallow; anterior edge relatively straight, posterior edge curved inwardly medially. Prosternum flat with transverse wrinkles; proepisternum without microsculpture. Procoxal setae absent; protibia distally expanded and shovel-like (Fig. 10B).
Elytra: Broad and moderately deflected; 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, 3 proximate and 1 double-spaced posterad (Fig. 41); suture well-defined; all striae with regularly spaced, asetose punctures, striae 1–4 defined by very small asetose punctures, striae 5–8 defined by slightly larger asetose punctures; intervals 1–4 flat to weakly convex, intervals 5–8 moderately convex, interval 6 terminated prior to basal margin; interval microsculpture present as fine lines; 7 th strial setal pattern with 3–4 setose punctures in anterior ½, 4–5 setose punctures in posterior ½ (Fig. 41), setose punctures large.
Ventral surface: Mesepisternum (Fig. 2) micropunctate and shallowly grooved; metepisternum with finely lineate; setose punctures present on mesocoxa (2) and metacoxa (2–3). Abdominal ventrite 1 without microsculpture, ventrite 2 finely lineate and finely pitted, ventrites 3–5 with 1 setose puncture each side of midline and finely lineate laterally; ventrite 6 setae present (Fig. 2): ♂ with 1 setose puncture each side at junction of straight apical edge and curve anterad, ♀ with 2–3 setose punctures each side, along rounded apical edge; ventrite 2 foveate laterally (shallow). Anterior metaventrite process a pointed triangle with an apically broad, narrowed posterad carina.
Male genitalia: Apical portion of penis lobe asymmetrically hooked with a slight deflection to right of vertical axis (VV) (Fig. 15C); apical portion narrow entire width (vertical plane), ventral process short and sharply pointed (Fig. 41 PL), apex upward curve symmetrical to form a long, narrow and bluntly rounded (almost flat) dorsal process with a short and flat recurve to shaft (Fig. 41 PL); shaft of penis lobe with moderate curve to right (ventral edge), especially apically (VV); penis lobe shaft narrow, overall length slightly curved ventrally (LV) (Fig. 16A). 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 without 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 narrowly rectangular with large dorsal hump forming a steep slope (60°) to arm (Fig. 41 LP); arm broad and short; terminal lobe short and narrowed with apical tuft of dense long setae; ventral edge straight with a comb of short to mediumlengthed setae sparsely distributed from mid-arm to mid-basal lobe (Fig. 41 LP). Right paramere long and narrowly triangular with a double row of long setae extended along apical ¾ of ventral edge (Fig. 41 RP).
Female genitalia: Basal gonocoxite 1 short and broad, internal dorso-lateral carina with 1 seta, ventral surface with rugose grooves across entire area. Gonocoxite 2 short, rounded and triangular, apically refexed. Ramus (Fig. 5) short and narrow.
Comments: There are a number of large Mecodema species in the Whangarei to Dargaville area; almost each mountain in the vicinity has a unique species.
Distribution: New Zealand, North Island, Northland, Tangitoria, Tangihua Forest.
Holotype: NZAC male labelled. NEW ZEALAND ND, Tangihua For., River Tk., PTs, DSS074 6–21 Dec 2012, DS Seldon, CAR247 / Regen. kauri-podocarp-broadleaf canopy, S35°53’06.7, 174°07’34.5, ca 86 m / HOLOTYPE Mecodema ngaitahuhu n. sp. design. DS Seldon, TR Buckley 2018 [red label].
Paratypes: 1, 1♀, NEW ZEALAND ND, Tangihua Forest, River Tk, PTs, 1 Feb 2013, DS Seldon / podocarpbroadleaf forest, within ca 50 m of river, CAR 216 ♀ (NZAC).
Etymology: This species is named for Ngai Tahuhu, whose rohe includes Tangihua Forest. Ngai Tahuhu were driven from their land during the mid-18th century by the Ngapuhi chiefs Te Ponaharakeke and Te Ngarokiteuru, who joined forces to accomplish this feat.
description: Published as part of Seldon, David S. & Buckley, Thomas R., 2019, The genus Mecodema Blanchard 1853 (Coleoptera: Carabidae: Broscini) from the North Island, New Zealand, pp. 1-148 in Zootaxa 4598 (1) on pages 78-79, DOI: 10.11646/zootaxa.4598.1.1, http://zenodo.org/record/2668063