Mecodema teparawhau, Seldon & Buckley, 2019

Seldon, David S. & Buckley, Thomas R., 2019, The genus Mecodema Blanchard 1853 (Coleoptera: Carabidae: Broscini) from the North Island, New Zealand, Zootaxa 4598 (1), pp. 1-148 : 116-118

Mecodema teparawhau sp. n.

Figure 57 .

Diagnosis: Differing from other North Island Mecodema species by having: 1, an indistinct vertexal groove with obsolescent punctures laterally; 2, 8–10 setae along prothoracic carina; 3, setal distribution along ventral edge of left paramere ( Fig. 57 LP).

Description: Length 26–32 mm, pronotal width 7.5–9.5 mm, elytral 8.6–10.6 mm. Colour of head and pronotum glossy black, elytra and ventrally matte black, coxae dark reddish-brown and legs black.

Head: Broad and flat ( Fig. 14A ). Vertex smooth; vertexal groove shallow but defined by obsolescent punctures laterally; large supraorbital puncture bearing 5 setae ( Fig. 57 ); 1 indistinct supraorbital groove mesad eyes; frons smooth, except shallow grooves in large depression each side proximate pits; frontoclypeal suture very narrow medially to indistinct in grooves around very small tentorial pits; anterior area of clypeus with well-defined grooves; clypeus with 1 setose puncture each side bearing 1–2 setae ( Fig. 57 ), some specimens may have medial setose puncture bearing 1 seta. Labrum rectangular, anterior edge rounded laterally, slightly emarginated medially with with 2 proximate central setae, 2 setae each side evenly spaced. Mentum lobes rounded ( Fig. 12F ), median process broad and short, slightly angled upward (15°), moderately indentate ( Fig. 12B ); setae variably absent or present. Submentum sclerite constriction narrow with 6 evenly spaced setae. Stipes with 2 basal setae. Gula pits small, suture defined, gula ( Fig. 8 ) flat and smooth. Gena with fine wrinkles medially forming an isodiametric pattern laterally.

Prothorax: Prothoracic carina narrow the entire length (slightly broadened at shoulder), slightly crenulated with 8–11 setae each side ( Fig. 57 ), extended to anterior angle; posterior lateral sinuation indistinctly carinate, parallel; pronotum broad and slightly deflected laterally, overall shape broadly cordate; midline poorly impressed, anterior medial impression triangular, posterior medial impression diamond-shaped present, disc with transverse wrinkles; pronotal foveae ( Fig. 11 ) shallow and narrow; anterior edge inwardly curved, posterior edge slightly emarginated medially. Prosternum concave and smooth; proepisternum with microsculpture. Procoxal setae absent; protibia distally expanded and shovel-like ( Fig. 10B ).

Elytra: Broad and deflected laterally; humeral angle evenly convex ( Fig. 6B ); basal margin moderately curved and gently sloped to base, interval 1 extended to base; lateral carina narrow the entire length, extended to humeral angle; humerus with 3 setose punctures; suture well-defined; striae with small, regularly spaced, asetose punctures, slightly increased in size laterally; intervals 1–8 slightly convex, interval 9 moderately convex; interval microsculpture absent; 7 th strial setal pattern with 3 setose punctures in anterior ½, 5 setose punctures in posterior ½ ( Fig. 57 ), setose punctures small.

Ventral surface: Mesepisternum and metepisternum without microsculpture; setose punctures present on mesocoxa (2) and metacoxa (2). All abdominal ventrites ( Fig. 2 ) finely lineate laterally; ventrites 1 and 2 with scattered obsolescent punctures, ventrites 3–5 with 1 setose puncture each side of midline; ventrite 6 setae present: ♂ with 1–2 setose punctures each side distantly situated at junction of straight apical edge and curve anterad; ♀ with 2–3 setose punctures each side, medially proximate, along rounded apical edge; lateral foveae absent. Anterior metaventrite process ( Fig. 2 ) a short triangle with a narrow carina the entire length.

Male genitalia: Apical portion of penis lobe asymmetrically hooked with a distinct deflection to right of vertical axis (VV) ( Fig. 15A ); ventral process a very small, bluntly rounded point ( Fig. 57 PL), apex asymmetrically curved upward to form a long and narrow dorsal process with a slightly recurved hook that is perpendicular to shaft, short, shape return curve to broadened apical part of shaft ( Fig. 57 PL); penis lobe shaft narrow the entire length, very gradually broadened to base; ventral edge of penis lobe with slight curve to right (VV); overall length of penis lobe moderate curved ventrally (LV) ( Fig. 16B ). 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 with projection; setal (scales) coverage of the apical plate moderate (26–75%); size of left setose flange small; size of right setose flange very large. Left paramere articulated at right angle to penis lobe, rectangular with slight dorsal hump forming a steep (60°) slope to arm ( Fig. 57 LP); arm short and narrow; terminal lobe short and broad with an apical tuft of a few short setae; medium-lengthed setae in a comb at arm-basal lobe junction with shorter setae extended a little way along curved ventral edge ( Fig. 57 LP). Right paramere long, narrowly triangular with a double row of long setae extended along apical ¾ of ventral edge ( Fig. 57 RP).

Female genitalia: Basal gonocoxite 1 short and broad, ventral surface smooth, internal dorso-lateral carina with 2 setae. Gonocoxite 2 a short rounded triangle with a slight upward curve apically. Ramus ( Fig. 5 ) long and broad.

Comments: The Whangarei area has a number of Mecodema species that inhabit the forested hills, and with all species it is difficult to determine their natural distributions due to the isolation induced by anthropogenic activities.

Distribution: New Zealand, North Island, Northland, Whangarei area, Pukenui Forest, Mt Parahaki.

Holotype: AMNZ male labelled. NEW ZEALAND, ND, Pukenui Forest , 9 May 2000, E. Conaghan / NZMS 260 Q07 245 0 96, on track / HOLOTYPE Mecodema teparawhau n. sp. design. DS Seldon, TR Buckley 2018 [red label] / AMNZ 40702 [green label] .

Paratypes: 1♂, 1♀, NEW ZEALAND, ND, Hirupaki Pa site, 3 March 1999, AM Booth / NZMS 260 Q06 269 124, in pitfall trap / AMNZ 40700 , 40701 [green labels]; 1♀, NEW ZEALAND ND, Whangarei , Pukenui For., Ridge Tk PTs DSS072 , 1 Feb 2013, CAR 225, D.S. Seldon ( NZAC); 2, Maungakaramea, Whangarei / 0 0 22, E. Fairburn 1925 / Mecodema scitulum Broun / 2593 / R.M. Gurr Collection / AMNZ 40756 [green label]; 2♂, 3, KAMO MT WHANGAREI 8.10.30 Coll. M. SIMPLEX [hw] / 2007. 163. 10866; 1 0867; 10868; 10869; 10870 ( NZAC); 5, KALMO MT WHANGAREI 8 :10:32 COLL. M. SIMPLEX [hw] / 2 007.163.10866–10870 (CMNZ).

Etymology: This species is named to honour Te Parawhau, an inland Whangarei hapu with close connections to Ngati Wai.

Figures

FIGURE 2. Ventral view of a Mecodema specimen showing specific morphological structures, excluding taxonomic structures indicated in detail figures, used in the species descriptions. ƑLF = ventrite lateral foveae; ƑSP = ventrite setose punctures; MTC = metacoxa; MTƑP = metaventrite process; MSC = mesocoxa; PC = procoxa; PS = prosternum; G = gena; PES = proepisternum; MSE = mesepisternum; MTE = metepisternum; Ƒ1–Ƒ6 = ventrites 1-6 (ventrites 1-3 may be fused); M = midline (dashed line, not a taxonomic structure).

FIGURE 4. An Environmental Scanning Electron Microscope (ESEM) photograph of the four main structures of the apical plate of the endophallus within the penis lobe. This is an example from Mecodema haunoho showing the central spicule (c.s), left (l.s.f) and the right setose flange (r.s.f), and microtrichial field (m.f). These structures are variable among species but within a species, they are very consistent, even over distant geographical ranges. The microtrichial field can be covered in flattened scales as in photo above, or with elongated setae-like scales.

FIGURE 5. The entire female reproductive tract (ventral view) including taxonomic structures (for all other abbreviated structure names see Seldon et al. 2012). However, for this revision only the following structures are important: HS = helminthoid sclerite; G1 = gonocoxite 1; G2 = gonocoxite 2; TDC = transverse dorsal carina; R = ramus.

FIGURE 6. Detail of the three different forms of the elytral humeral angle: (A) = anteriorly convergent (M. parataiko), (B) = evenly convex (M. oconnori), (C) = subangulate (M. atuanui).

FIGURE 8. Detail of the ventral head with the taxonomic structures used in the species descriptions. SBMS = submentum setae; SBM = submentum sclerite; ML = mentum lobe; MP = mentum process (with indentation); MPW = mentum process width; SBS = stipes basal setae; MPL = mentum process length; MPS = mentum process setae; SBMC = submentum sclerite constriction; GP = gula pits; GS = gula suture.

FIGURE 10. The protibia form is a character used mainly to determine between genera, except for one species in Mecodema where the difference between (A) greatly distally expanded (M. antarctica) and (B) expanded distally (all other Mecodema species) is used.

FIGURE 11. Detail of pronotum showing the taxonomic structures used in the species descriptions. PPC = posterior pronotum constriction; PS = pronotal setae; PAA = pronotum anterior angle; AE = anterior edge; PC = pronotal carina; ML = midline; PF= pronotal foveae; PPS = pronotum posterior sinuation; PE = posterior edge.

FIGURE 12. Ventral view of the mentum with a number of different character states. Illustrations A–D are the different forms of the indentation in the apex of the median process: (A) distinctly indentate (M. manaia); (B) moderately indentate (M. pluto); (C) slightly indentate (M. infimate); (D) indentation notched (M. parataiko). Illustrations E–G are the three general forms (i.e., hashed lines) of the mentum lobes: (E) triangular; (F) rounded; (G) squared.

FIGURE 14. Diagrammatic cross sections that represent the width and convexity of head or deflection of pronotum (frontal view): (A) broad and flat; (B) broad and convex; (C) narrow and flat; (D) narrow and convex.

FIGURE 15. The penis lobe in ventral view showing the relative deflection to right of vertical: (A) distinctly deflected (M. regulus); (B) moderately deflected (M. haunoho); (C) slightly deflected (M. oregoides). Scale bars = 1 mm. Structures of penis lobe indicated are: base (B); lateral edge (LE); apical portion (AP); ventral edge (ƑE).

FIGURE 16. Relative strength of the ventral curve over the length of the penis lobe (lateral view): (A) slightly curved (M. oblongum); (B) moderately curved (M. ponaiti); (C) distinctly curved (M. manaia). Scale bar = 1 mm.

FIGURE 57. Mecodema teparawhau plate with half habitus (left) and the three (detached) structures of the male aedeagus: the right (RP) and left parameres (LP), plus the penis lobe (PL). The bottom scale bar is the width across the widest point of the pronotum of the specimen used for this habitus and top scale bar equates to the half the length of the penis lobe.