Mecodema rusticulus 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 rusticulus

description: Mecodema rusticulus sp. n.
Figure 51.
Diagnosis: Differs from other North Island Mecodema species by: 1, the small supraorbital puncture (may consist of 2–3 separate punctures) bearing 4–5 setae; 2, the elytral striae with small, regularly spaced, asetose punctures, some obsolescent laterally; 3, the discus-shaped shape of the apical portion of the penis lobe (Fig. 51 PL).
Description: Length 25.3–33.5 mm, pronotal width 7–8.6 mm, elytral width 8.2–10.3 mm. Colour of entire body matte to glossy black, coxae to tarsi dark reddish-brown to black.
Head: Broad and moderately convex (Fig. 14B). Vertex with fine lines forming an isodiametric pattern; vertexal groove defined by sparsely distributed punctures, laterally broad (Fig. 51); small supraorbital puncture (may consist of 2–3 separate punctures) bearing 4–5 setae; 3 or more poorly defined supraorbital grooves that may extend onto lateral area of frons; frons medially convex with a large and shallow depression each side of midline; frontoclypeal suture and tentorial pits indistinct; anterior area of clypeus (Fig. 9) with broad, well-defined grooves, l setose puncture each side bearing 1–2 setae (Fig. 51), central puncture bearing 2 setae (some specimens without central setose puncture). Labrum rectangular, anterior edge outwardly curved, moderately emarginated medially with 2 proximate central setae, 2 setae each side evenly spaced. Mentum lobes rounded (Fig. 12F), median process very short and broad, slightly angled upward (15°) moderately indentate (Fig. 12B); mentum setae absent. Submentum sclerite constriction broad with 6 regularly spaced setae. Stipes with 2 basal setae. Gula pits (Fig. 8) small to indistinct, suture indistinct, gula flat with transverse lines. Gena with fine lines forming an isodiametric pattern across entire area.
Prothorax: Prothoracic carina (Fig. 11) narrow the entire length, crenulations absent with 7–11 setae each side, extended beyond anterior angle; posterior lateral sinuation evidently carinate, slightly angled inward; pronotum broad and deflected laterally, overall shape cordate (Fig. 51); midline well-defined, anterior medial triangular impression and posterior medial diamond-shaped impresson present, disc with fine transverse wrinkles laterally; pronotal foveae shallow and broad; anterior edge slightly inwardly curved, posterior edge straight. Prosternum flat with fine transverse lines; proepisternum without microsculpture. Procoxal setae absent; protibia distally expanded and shovel-like (Fig. 10B).
Elytra: Broad and slightly deflected laterally; humeral angle anteriorly convergent (Fig. 6A); basal margin slighly curved and gently sloped to base, interval 1 extended to margin; lateral carina narrow the entire length, extended to humeral angle; humerus with 3–4 proximate setose punctures, 4 th or 5 th double-spaced posterad (Fig. 51); suture poorly impressed; striae with small, regularly spaced, asetose punctures, some obsolescent laterally; intervals 1–6 weakly convex, intervals 7–9 moderately convex, interval microsculpture present in form of very fine transverse lines; 7 th strial setal pattern with 3 setose punctures in anterior ½, 5 setose punctures in posterior ½ (Fig. 51), setose punctures large.
Ventral surface: Mesepisternum (Fig. 2) and metepisternum without microsculpture (may be a few fine lines); setose punctures present on mesocoxae (2) and metacoxae (2). Abdominal ventrites 1 and 2 without lines; ventrites 3–5 finely lineate, 1 setose puncture each side of midline; ventrite 6 setae present: ♂ with 1 setose puncture each side at junction of straight apical edge and curve to anterior, ♀ with 2–3 setose punctures each side along bluntly pointed apical edge; lateral foveae absent. Anterior metaventrite (Fig. 2) rounded with nipple-like extension, carina apically broad but narrowed significantly toward coxa.
Male genitalia: Apical portion of penis lobe discus-shaped, asymmetrically rounded with very distinct deflection to right of vertical (VV) (Fig. 15A); ventral process a bluntly, rounded point (Dome Valley) to sharply pointed in specimens from Pukekororo S.R. and Logues Bush S.R., dorsal process slightly flattened proximate the shaft (Fig. 51 PL), shaft of penis lobe narrowed toward discus-shaped apical portion, especially dorsally, ventral edge of penis lobe straight (VV); 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 rounded; 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 very large. Left paramere basal lobe rectangular with large dorsal hump that forms steep angle (60°) to arm (Fig. 51 LP); arm narrow and very short; apical lobe slightly broadened than arm but same length as arm, apical tuft of sparse, short setae, then a small number of short setae in junction curve of basal lobe and arm (Fig. 51 LP); ventral edge of basal lobe straight. Right paramere long, narrowly triangular with a double row of long setae extended along apical ¾ of ventral edge (Fig. 51 RP); apical ⅓ slightly inwardly curved toward penis lobe.
Female genitalia: Basal gonocoxite 1 long and broad (broadened apically), ventral surface with a few rugose wrinkles, internal dorso-lateral carina with 3 setae. Gonocoxite 2 (Fig. 5) ovate, slightly reflexed apically. Ramus long and broad.
Comments: Mecodema rusticulus ranges from Dome Valley north to the Brynderwyn Hills, including Pukekororo S.R. and eastern forest remnants to the coast (e.g., Logues Bush). Many of these populations are not accessible due to a rahui imposed by local iwi to inhibit removal and collection of material from native forest remnants that have kauri (Agathis australis) trees affected by kauri dieback disease.
Distribution: New Zealand, North Island, Auckland, northern Rodney District, Logues Bush S.R., Pukekororo S.R., Dome Valley S.R.
Holotype: NZAC, male labelled. NEW ZEALAND AK, Logues Bush S.R. 24 II–02 III 1999 #1106, 1108 P. Paquin & N. Dupérré / Pitfall traps Moist podocarp x broadleaf forest Landscape Patch Dynamic Project / HOLOTYPE Mecodema rusticulus n. sp. design. DS Seldon, TR Buckley 2018 [red label].
Paratypes: 1♀, NEW ZEALAND AK, Logues S.R. 22–29 XII 1998 #205 # 243 P. Paquin & N. Dupérré / Pitfall traps. Moist podocarp x broadleaf forest Landscape Patch Dynamic Project (NZAC); 1♀, NEW ZEALAND AK, Logues Bush S.R. 03–10 II 1999 # 818 P. Paquin & N. Dupérré / Pitfall traps Moist podocarp x broadleaf forest Landscape Patch Dynamic Project (NZAC); 1♀, NEW ZEALAND AK, Logues Bush S.R. 17–24 II 1999 #1013 P. Paquin & N. Dupérré / Pitfall traps Moist podocarp x broadleaf forest Landscape Patch Dynamic Project (NZAC); 1♀, 1♂, NEW ZEALAND AK, Logues Bush S.R. 02– 09 III 1 999 #1205, #1201 P. Paquin & N. Dupérré / Pitfall traps Moist podocarp x broadleaf forest Landscape Patch Dynamic Project (NZAC); 1♀, NEW ZEALAND AK, Logues S.R. 30 III- 06 IV 1 999 #1586 P. Paquin & N. Dupérré / Pitfall traps Moist podocarp x broadleaf forest Landscape Patch Dynamic Project (NZAC); 1♂, NEW ZEALAND AK, Logues Bush S.R. 24 II–02 III 1999 #1106, 1108 P. Paquin & N. Dupérré / Pitfall traps Moist podocarp x broadleaf forest Landscape Patch Dynamic Project (NZAC); 3♂, NEW ZEALAND AK, Logues S.R. 26 I–03 II 1999 #722 (2), 723 P. Paquin & N. Dupérré / Pitfall traps Moist podocarp x broadleaf forest Landscape Patch Dynamic Project (NZAC); 1♀, NEW ZEALAND AK, Logues Bush S.R. 09–16 III 1999 #1298 P. Paquin & N. Dupérré / Pitfall traps Moist podocarp x broadleaf forest Landscape Patch Dynamic Project (NZAC); 1♀, NEW ZEALAND AK, Pukekaroro Sce. Res., 3613 S 17444 E, 150 m, 12.XI–10.XII 2001, Larivière. Larochelle / wet podocarp x taraire forest, steep slopes pittraps (NZAC); 1♂, NEW ZEALAND AK, Pukekaroro Sce. Res., 3613 S 17444 E, 150 m, 15.X–12.XI 2001, Larivière. Larochelle / wet podocarp x taraire forest, steep slopes pittraps (NZAC); 3(♂, ♀), NEW ZEALAND AK, Dome Valley walkway, 3637 S 17462 E, 200 m, 10.XII 2001– 14.I.2002, Larivière. Larochelle / wet tree fern forest, steep slopes (NZAC); 2(♂, ♀), NEW ZEALAND AK, Dome Valley walkway, 3637 S 17462 E, 200 m, 12. XI–10.XII 2001, Larivière. Larochelle / wet tree fern forest, steep slopes (NZAC); 3♂, 2♀, NEW ZEALAND AK, Dome Valley walkway, 3637 S 17462 E, 200 m, 15.IX–15.X 2001, Larivière. Larochelle / wet tree fern forest, steep slopes (NZAC); 1♂, NEW ZEALAND AK, Warkworth Dome Valley 14 Jan 1997 S.E. Thorpe (NZAC); 1, NEW ZEALAND AK, Warkworth Dome Valley 2 Feb 1997 S.E. Thorpe (NZAC); 1♂, Dome Valley bush near Warkworth 17.11.44 B.B. Given (NZAC); 1 [card mounted], NEW ZEALAND AK, Mt Dome nr Warkworth 26.11.95 MB Nunn / J. Nunn Collection (NZAC); 1♂, NEW ZEALAND, ND Brynderwyns, 25 Aug 1989 PJ Anderson / NZMS 260 Q08 427 683 in leaf / AMNZ 40704 [green label]; 1, Matakana Nth Auck. Oct 1959 V.A Nicholls [hw] / AMNZ 84329 [green label].
Etymology: As this species is found in native forests in the most northern areas of the Auckland supercity, more rural than urban, so it is named rusticulus, meaning yokel.
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 101-104, DOI: 10.11646/zootaxa.4598.1.1, http://zenodo.org/record/2668063