Mecodema crenaticolle Redtenbacher 1868
Creators: name: Seldon, David S.
name: Buckley, Thomas R.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Carabidae
Mecodema
Mecodema crenaticolle

description: Mecodema crenaticolle Redtenbacher, 1868.
Figure 23.
Mecodema rugicolle Broun, 1882 (nr Taranaki, TK), synonymised by Britton 1949.
Mecodema lineatum Broun, 1894 (Ligar’s Bush, AK), synonymised by Lewis 1902.
Diagnosis: Distinguishable from other North Island Mecodema species by having: 1, the pronotum carina strongly crenulated; 2, elytral striae 1–4 with large star-shaped asetose punctures in an irregular pattern, striae 5–7 with asetose punctures not star-shaped, but irregularly spaced; 3, an elytral setose puncture basad scutellum.
Description: Length 21–27.9 mm, pronotal width 5.8–7.3 mm, elytral width 6.7–8.6 mm. Colour of entire body reddish-brown to black.
Head: Broad and convex (Fig. 14B). Vertex with coarse transverse wrinkles laterally, becoming an isodiametric pattern toward pronotum; vertexal groove (Fig. 8) defined by punctures and coarse wrinkles the entire length; small supraorbital puncture bearing 3–4 setae, greater than 3 well-defined supraorbital grooves anterad eyes (Fig. 23), extended onto frontoclypeal area; frons with a few scattered punctures between supraorbital punctures, cuticle raised medially, a shallow depression each side of midline (anteriorly); frontoclypeal suture absent, tentorial pits indistinct within grooves; anterior area of clypeus (Fig. 9) with shallow grooves, 1 small setose puncture on each side bearing 2 setae (a medial puncture bearing 1 seta may be present). Labrum rounded laterally, anterior edge outwardly curved with 2 proximate central setae, 2 setae each side evenly spaced. Mentum lobes squared (Fig. 12G), median process broad and short, apex slightly angled upward (15°), distinctly indentate (Fig. 12A); mentum setae present. Submentum sclerite constriction (Fig. 8) narrow, broadened laterally with 6 regularly spaced setae. Stipes with 2 basal setae. Gula pits small, suture well-defined, gula flat with rugose transverse lines. Gena convex and entirely covered with transverse tight wrinkles that form an isodiametric pattern laterally.
Prothorax: Prothoracic carina (Fig. 11) very narrow the entire length, distinctly crenulated with 6–10 relatively evenly spaced setae along each side (Fig. 23), extended to anterior angle; posterior lateral sinuation evidently carinate, parallel or slightly angled outward (very distinctive as it is formed by foveael groove); pronotum laterally deflected, disc with deep transverse grooves laterally (less impressed proximate the midline), overall shape cordate, medial impressions absent; pronotal foveae (Fig. 11) broad and deep, partially formed by convexity of pronotal lateral margin; anterior edge distinctly inwardly curved, convexity forming ridge that is grooved perpendicular to anterior edge, posterior edge distinctly emarginated medially. Prosternum (Fig. 2) flat with a shallow depression each side of midline; proepisternum moderately wrinkled and pitted. Procoxal setae absent; protibia distally expanded and shovel-like (Fig. 10B).
Elytra: Narrow and deflected laterally, posterior end of elytra steep to apex; humeral angle anteriorly convergent (Fig. 6A); basal margin angled perpendicular to humeral angle and bevelled to base; lateral carina (Fig. 1) very narrow from apex to humerus (may be broadened in posterior ⅓), distinctly crenulated in anterior ⅓ to slightly crenulated in posterior ⅓, extended to humeral angle, carina with a distinctive curve inwardly posterad humerus; humerus with 3 deep setose punctures; suture well-defined; stria 1 anterior area with small, asetose punctures in a row, medial punctures increased in size, apical punctures star-shaped; stria 2 defined by evenly distributed star-shaped punctures, striae 3–5 obliterated by large star-shaped punctures in confused distribution, striae 6–8 more discernible as irregularly sized and spaced, asetose punctures (Fig. 23); intervals 1 and 2 visible, extended to scutellum but not defined by striae, interval 3 convex in posterior ⅓, intervals 4–8 undefined; 7 th strial setal pattern with 4 setose punctures in anterior ½, 4–6 setose punctures in posterior ½, setose punctures large; a single seta each side near base end of stria 2 (Fig. 23).
Ventral surface: Mesepisternum with corrugose wrinkles; metepisternum moderately punctured, punctures continue to lateral area of ventrites 1 and 2; setose punctures present on mesocoxae (2) and metacoxae (3). Abdominal ventrites 1 and 2 finely lineate and finely micropunctate extended to coxa; ventrites 3–5 with 1 deep, setose puncture each side of midline, ventrites foveate laterally; ventrite 6 setae present: ♂ with a pair of setae each side, posterior edge straight; ♀ with 1 pair each side, 1 proximate apex, posterior edge a rounded point. Anterior metaventrite process a short triangle with a very well-defined and broad carina the entire length.
Male genitalia: Apical portion of penis lobe asymmetrically hooked with a moderate deflection to right of vertical axis (VV) (Fig. 15B); dorsal process (Fig. 3) a narrow and bluntly rounded hook that is slightly pushed forward of perpendicular, apex with an asymmetrical curve downward to form the ventral process (Fig. 3), that is a very bluntly rounded point, half the size of the dorsal process (Fig. 23 PL); penis lobe shaft equally narrow width the entire length, apical portion straight (VV); overall length of penis lobe 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 long and narrow; relative setal (scales) coverage of the apical plate moderate (26–75%); size of left setose flange large; size of right setose flange very large (long). Left paramere basal lobe rectangular with a very pronounced dorso-anterior hump (70–80°) angle sloping to arm; arm very narrow and continued to terminal lobe (not distinguishable from arm), apical tuft without setae, sparsely scattered setae along apical ⅓ of ventral edge (Fig. 23 LP); ventral edge of basal lobe straight. Right paramere triangular with a pronounced anterio-dorsal hump (Fig. 23 RP), arm longer than basal lobe, a double row of long setae reducing in number along apical ¾ of ventral edge.
Female genitalia: Basal gonocoxite 1 long and broad with ventral surface smooth, internal dorso-lateral carina with 3 short setae. Gonocoxite 2 (Fig. 5) a rounded triangle, paddle-like, ventral surface with numerous sensilla. Ramus long and narrow.
Comments: There is some variation inpronotal and elytral characters among North Island populations, but the umbilitical setose punctures of humerus are stable. Mecodema crenaticolle is widespread from the Wellington Region to the Hunua Range, Auckland, with the western populations of Whanganui and Mt Taranaki showing the most morphological variation. Mecodema crenaticolle can be distinguished from its sister species, M. crenicolle (South Island) by having large, star-shaped, asetose punctures medially, and the ventral surfaces are defined by rugose wrinkles and punctures.
Distribution: New Zealand, North Island, Auckland, Coromandel, Bay of Plenty, Waikato, Taupo, Taranaki, Rangitikei, Wanganui, Wellington.
Holotype: (not viewed). Type in the Museum of Natural History, Vienna.
Paratypes (Mecodema crenaticolle): BMNH, male labelled. 2594. ♂ [hw] / Type [round label with red border] / New Zealand [red underline] Broun Coll. Brit Mus. 1922—482 / Ligar’s Bush. Papakura [hw] / Mecodema lineatum [hw] / Mecodema crenaticolle Redt. [hw] Compared to type E.B.B.; BMNH. Type [round label with red border] / 1322 / New Zealand [red underline] Broun Coll. Brit Mus. 1922—482 / Taranaki / card-mounted male genitalia / Mecodema rugicolle [hw].
Material examined: 1 ♀, NZ WO 7 km W Karamu 14.XI.1992 A. Larochelle. M-C Larivière / Totara and tree fern for., under pieces of wood (NZAC); 1, NEW ZEALAND. TK. Mt Taranaki, Lower Lake Dive Tk, 28 Mar 2106, D.S. Seldon, F.R. Schnitzler, M. Dickison. / Low broadleaf canopy, log rolling, S39°19’17.2 E174°05’50.1 984 m (WMNZ); 2, NEW ZEALAND. TK. Mt Taranaki, Sir Eds Seat Tk, 28 Mar 2106, D.S. Seldon, F.R. Schnitzler, M. Dickison. / Very low broadleaf canopy, under logs, S39°19’16.4 E174°05’44.8, 1013 m (WMNZ).
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 36-39, DOI: 10.11646/zootaxa.4598.1.1, http://zenodo.org/record/2668063