Mecodema quoinense Broun 1912
Creators: name: Seldon, David S.
name: Buckley, Thomas R.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Mecodema
Mecodema quoinense

description: Mecodema quoinense Broun, 1912.
Figure 49.
Diagnosis: Distinguishable from all other North Island Mecodema species by: 1, striae 5–6 well-defined by asetose proximate punctures (interval very narrow), striae 7–8 comprise of a double row of punctures (no interval); 2, the rectangular shape of the apical portion of the penis lobe (Fig. 49 PL).
Description: Length 23.7–24.7 mm, pronotal width 6.2–7 mm, elytral width 7.1–8.1 mm. Colour of entire body matte dark reddish-brown to matte black, coxae and tibiae dark reddish-brown, femur bright red or black.
Head: Narrow and convex (Fig. 14D). Vertex micropunctate, wrinkled grooves (Fig. 49) and very fine wrinkles forming an isodiametric pattern laterally; vertexal groove micropunctate and wrinkled grooves the entire length, a broad shallow depression laterally; small supraorbital puncture bearing 3–4 setae; 3–4 shallow supraorbital grooves, extended on to frons anterior to eye; frons (Fig. 9) medially convex with a large and shallow depression each side of midline, grooves laterally, plus wrinkled grooves and pitting in posterior region (Fig. 49); frontoclypeal suture indistinct between very small tentorial pits; anterior clypeus with a central groove, extended forward laterally, rounded and anterior edge angled backward medially; clypeus area mesad setose punctures medially convex, 1 small setose puncture each side bearing 2 setae. Labrum rounded, anterior edge slightly emarginated with 2 proximate central setae, 2 setae each side evenly spaced. Mentum lobes rounded (Fig. 12F), median process long and broad, strongly angled upward (60°), distinctly indentate (Fig. 12A); mentum setae present. Submentum sclerite constriction narrow with 6 relatively evenly-spaced setae. Stipes with 2 basal setae. Gula pits (Fig. 8) very small, suture indistinct, gula flat and smooth. Gena with rugose transverse wrinkles becoming corrugose toward prosternum (medially), fine wrinkles forming an isodiametric pattern laterally.
Prothorax: Prothoracic carina broad the entire length, slightly crenulated with 8–10 setae each side (Fig. 49), extended beyond anterior angle; posterior sinuation defined as a continuation of carina, evidently carinate, inwardly angled; pronotum narrow and deflected, overall shape triangularly cordate with a raised carina behind anterior edge, very fine, transverse wrinkles across entire disc (Fig. 49), isodiametric pattern across antero-lateral region; midline indistinct, anterior medial triangular impression and posterior medial diamond-shaped impression present; pronotal foveae (Fig. 11) small and deep; anterior edge moderately inwardly curved, posterior edge straight. Prosternum flat with evenly-spaced, fine transverse lines, medial depression; proepisternum micropunctate. Procoxal setaeabsent; protibia distally expanded and shovel-like (Fig. 10B).
Elytra: Narrow and flat; humeral angle anteriorly convergent (Fig. 6A); basal margin moderately curved and bevelled to base, interval 1 extended to scutellum; lateral carina narrow the entire length, extended to humeral angle; humerus with 1 setose puncture; suture poorly defined; intervals slightly convex, convexity increased laterally, interval microsculpture present as fine transverse lines, interval 8 very broad, forming the side of the elytra to the carina; striae 1–4 with obsolescent asetose punctures (anterad and posterad), striae 5–6 well-defined by asetose proximate punctures (interval very narrow), striae 7–8 comprise of a double row of punctures (no interval); 7 th strial setal pattern with 0–3 setose punctures in anterior ½, 3–4 setose punctures in posterior ½ (Fig. 49), setose punctures small.
Ventral surface: Mesepisternum with deep grooves (may be micropunctate); metepisternum with defined grooves proximate coxae; setose punctures present on mesocoxae (2) and metacoxae (2). All abdominal ventrites (Fig. 2) finely lineate laterally; ventrites 1–3 micropunctate; ventrites 3–5 with 1 setose puncture each side of midline; ventrites 6 setae present: ♂ with 2 evenly spaced setae on bluntly rounded apical edge, ♀ specimen damaged; some ventrites foveate laterally (shallow). Anterior metaventrite process a short, sharply-pointed triangle with a broad and well-defined carina the entire length.
Male genitalia: Apical portion of penis lobe asymmetrically rounded without deflection to right (VV); apical portion shape almost squared, ventral process with slight point before apically flat curve upward to form the flatly curved dorsal process, that has a curved hollow in shaft to determine apex (Fig. 49 PL); shaft of penis lobe narrow the entire length, ventral edge with distinct curve to right (VV); overall length of the penis lobe moderately curved ventrally, especially apical portion (LV) (Fig. 16C). Structures of the endophallus (Fig. 4): lateral form of the apex of the central spicul rounded; dorsal form of the apex of the central spicule expanded; setal (scales) coverage of the apical plate extensive (76–100%); size of left setose flange small; size of right setose flange very large. Left paramere basal lobe articulated at right angle, rectangular without dorsal hump but steeply sloped (60°) to arm (Fig. 49 LP); arm short and narrow; terminal lobe broad and short with apical tuft of medium-lengthed setae; setae extended along apical portion to arm-basal lobe junction; ventral edge straight (Fig. 49 LP). Right paramere is a long and narrowly rectangular with a slight dorsal hump that forms a steep slope to arm, gradually narrowed to terminus, setae extended along apical ½ of ventral edge (Fig. 49 RP).
Female genitalia: Basal gonocoxite 1 (Fig. 5) short and broad, broadened toward gonocoxite 2, ventral surface with a few parallel, rugose wrinkles, internal dorso-lateral carina without setae; dorsally flattened carina in apical half. Gonocoxite 2 broadly triangular and apically reflexed. Ramus short and broad basally, narrowed apically, apical portion slightly curved inward.
Comments: Britton (1949) used the character ‘bright red femora’ to distinguish Mecodema quoinense from other Mecodema species in the area. However, this character is difficult to see in old, dry and pinned specimens, as well as being a relatively common occurrence in many other species. Britton should have utilised the male genitalia as the apical portion of the penis lobe is significantly different from any other Mecodema species.
Distribution: New Zealand, North Island, Wellington, Tararua Range, Mt Quoin and Mt Holdsworth.
Holotype: BMNH male labelled. Mecodema quoinense ♂ [hw] / Mount Quoin 3900 ft. [hw] / New Zeal. [red underline] Broun Coll. Brit. Mus. 1922-482. / 3167 [hw] / Type [round label with red border].
Material examined: 1♀ [card mounted], Mt. Holdsworth 3000’ 25.1.1907 [hw] G.V. HUDSON / Mecodema quoinense Br. [hw], E.B. Britton det. Comp. with Type. / AI.10446 (MONZ); 1♀, ex J.J. Walker bequest 1939 / Ex Coll. Mus. Otago [hw] / Brit. Mus. 1948 129 / Mecodema quoinense Broun [hw] Compared with type. E.B.B. (BMNH).
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 97-99, DOI: 10.11646/zootaxa.4598.1.1, http://zenodo.org/record/2668063