Mecodema, Blanchard, 1853

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 : 14-16

Key to North Island Mecodema

(includes new combinations of South Island only taxa).

1. Ventrites 3–5 ( Fig. 2 ) with numerous setose punctures each side of midline..................................... 2

- Ventrites 3–5 without setose punctures or with 1–3 setose punctures each side of midline........................... 5

2(1). Protibia ( Fig. 10 ) and mesotibia greatly distally expanded and distinctly inwardly curved.............................................................................................. M. antarctica Castelnau, 1867 , comb. n.

- Protibiae distally expanded without inward curve, mesotibiae slender.......................................... 3

3(2). Elytra striae with numerous long setae in apical ¼............................. M. tibiale Castelnau, 1867 , comb. n.

- Elytra striae with several setae in apical ¼................................................................ 4

4(3). Mesocoxa ( Fig. 2 ) with 1 setose puncture, metacoxa with 2 setose punctures....... M. moniliferum Bates, 1867 , comb. n.

- Mesocoxa with 2–3 setose punctures, metacoxa with 2–3 setose punctures.......... M. aberrans Putzeys, 1868 , comb. n.

5(1). Elytra narrower than pronotum at the widest point........................................ M. chaiup Seldon, 2015

- Elytra broader than pronotum at the widest point ( Fig. 1 ).................................................... 6

6(5). Ventrite 3 without setose punctures each side of midline..................................................... 7

- Ventrite 3 with setose punctures present each side of midline................................................ 18

7(6). Mesocoxa and metacoxa without setose punctures.......................................................... 8

- Mesocoxa and metacoxa each with at least 1 setose puncture................................................ 11

8(7). Number of submentum sclerite setae 2–4 (Little Barrier Is. only)................. M. haunoho Seldon & Leschen, 2011

- Number of submentum sclerite setae 4–6 ( Fig. 8 )........................................................... 9

9(8). Vertex without macrosculpture ( Figs 1 and 9 )............................................................. 10

- Vertex with rugose wrinkles............................................. M. parataiko Seldon & Leschen, 2011

10(9). Prothoracic carina slightly crenulated (Great Barrier Is. only)................... M. aoteanoho Seldon & Leschen, 2011

- Prothoracic carina without crenulations (smooth)............................... M. kokoromatua Seldon et al., 2012

11(8). Mesocoxa with 1–2 setose punctures, metacoxa without setose punctures...................................... 12 - Mesocoxa with 1 setose puncture (or absent), metacoxa with 1 setose puncture.................................. 16

12(11). Prothoracic carina bearing 7–10 setae along each side ( Fig. 11 )............................... M. atrox Britton, 1949

- Prothoracic carina bearing 2–6 setae along each side....................................................... 13

13(12). Submentum sclerite constriction narrow ( Fig. 12F )........................................................ 14

- Submentum sclerite constriction broad.................................................................. 15

14(13). Prothoracic carina bearing 4–6 setae along each side.................................... M. curvidens Broun, 1915

- Prothoracic carina bearing 2–4 setae along each side........................................ M. perexiguus sp. n.

15(13). Vertexal groove ( Fig. 9 ) narrow and shallow, broadened laterally (Poor Knights Is. only).................................................................................................. M. ponaiti Seldon & Leschen, 2011

- Vertexal groove narrow and defined along the entire length.................................. M. pluto Britton, 1949

16(11). Prothoracic carina bearing 4–6 setae along each side....................................................... 17

- Prothoracic carina bearing 2–4 setae along each side............................ M. manaia Seldon & Leschen, 2011

17(16). Mesocoxa ( Fig. 2 ) without setose punctures (Three Kings Is. only)........................... M. regulus Britton 1964

- Mesocoxa with setose punctures (Cape Reinga to North Cape)..................... M. tenaki Seldon & Leschen, 2011

18(6). Mentum with setae present ( Fig. 8 )..................................................................... 19

- Mentum without setae............................................................................... 25

19(18). Pronotal disc with asetose punctures................................................... M. florae Britton, 1949

- Pronotal disc without asetose punctures................................................................. 20

20(19). Asetose punctures of elytral striae regularly spaced........................................................ 21

- Asetose punctures of elytral striae irregularly spaced....................................................... 23

21(20). Mesocoxa with 1 setose puncture........................................................... M. temata sp. n.

- Mesocoxa with 2 setose punctures..................................................................... 22

22(21). Metacoxa without setose punctures, mesepisternum ( Fig. 2 ) with rugose wrinkles............. M. quoinense Broun, 1912

- Metacoxa with setose punctures, mesepisternum with sparse punctures..................... M. oblongum Broun, 1882

23(20). Intervals 1–4 ( Fig. 1 ) of elytra are indistinct or absent...................................................... 24

- Intervals 1–4 of elytra are flat or weakly convex............................................... M. zonula sp. n.

24(23). Asetose punctures of elytral striae are indistinct near suture...................... M. crenaticolle Redtenbacher, 1868

- Asetose punctures of elytral striae 1–4 are long and narrow............................... M. longicolle Broun, 1923

25(18). Ventrites 3–5 with 2 setose punctures each side of midline.................................................. 26

- Ventrites 3–5 with 1 setose puncture each side of midline................................................... 27

26(25). Mesocoxa with 4 setose punctures.................................................... M. hector Britton, 1949

- Mesocoxa with 2 setose punctures....................................................... M. kokoroiho sp. n.

27(25). Vertex without microsculpture/macrosculpture............................................................ 28

- Vertex with microsculpture/macrosculpture.............................................................. 34

28(27). Vertexal groove with punctures........................................................................ 29

- Vertexal groove without punctures..................................................................... 31

29(28). Vertexal groove defined by punctures laterally only.......................................... M. undecimus sp. n.

- Vertexal groove defined by punctures along the entire length................................................ 30

30(29). Pronotum foveae are deep and broad; prosternum with microsculpture/macrosculpture.......... M. validum Broun, 1923

- Pronotum foveae are shallow and narrow; prosternum without microsculpture/macrosculpture.......... M. papake sp. n.

31(28). Pronotal carina with greater than 10 setae along each side...................................... M. argentum sp. n.

- Pronotal carina with 7–10 setae along each side........................................................... 32

32(31). Prosternum is concave................................................................ M. teparawhau sp. n.

- Prosternum is flat................................................................................... 33

33(32). Mesepisternum micropunctate.......................................................... M. ngaitahuhu sp. n.

- Mesepisternum with rugose wrinkles.................................................... M. ngaiatonga sp. n.

34(27). Metacoxa with 3 setose punctures...................................................................... 35

- Metacoxa with 2 or less setose punctures................................................................ 38

35(34). Submentum sclerite constriction narrow................................................................. 36

- Submentum sclerite constriction broad.................................................................. 37

36(35). Labrum ( Fig. 9 ) lobate with anterior edge distinctly emarginated............................... M. dunnorum sp. n.

- Labrum rectangular with anterior edge outwardly curved and slightly emarginated................... M. tewhara sp. n.

37(35). Mesepisternum with punctures............................................................ M. godzilla sp. n.

- Mesepisternum without punctures.......................................................... M. teroroa sp. n.

38(34). Pronotal carina with 7–10 setae along each side........................................................... 39

- Pronotal carina with 11+ setae along each side............................................................ 45

39(38). Submentum sclerite constriction narrow ( Fig. 12F )......................................... M. dux Britton, 1949

- Submentum sclerite constriction broad.................................................................. 40

40(39). Vertexal groove shallow and broad, without punctures........................................ M. xylanthrax sp. n.

- Vertexal groove with punctures........................................................................ 41

41(40). Vertexal groove with punctures distributed along the entire length............................................ 42

- Vertexal groove punctures distributed laterally only........................................................ 43

42(41). Submentum sclerite constriction narrow............................................. M. simplex Castelnau, 1867

- Submentum sclerite constriction broad................................................ M. scitulum Broun, 1894 43(41). Proepisternum ( Fig. 2 ) micropunctate....................................................... M. atuanui sp. n.

- Proepisternum without microsculpture.................................................................. 44

44(43). Vertex with fine lines forming an isodiametric pattern........................................ M. rusticulus sp. n.

- Vertex with a few scattered punctures, surface otherwise smooth............................. M. genesispotini sp. n.

45(38). Elytral intervals without microsculpture................................................................. 46

- Elytral interval with microsculpture lineate.............................................................. 47

46(45). Anterior metaventrite process ( Fig. 2 ) with the carina width broad the entire length.................... M. kipjac sp. n.

- Anterior metaventrite process with the carina width narrow the entire length.................... M. wharekahika sp. n.

47(46). Vertexal groove without punctures......................................................... M. jacinda sp. n.

- Vertexal groove with punctures........................................................................ 48

48(47). Prosternum with transverse lines............................................................. M. mohi sp. n.

- Prosternum without microsculpture..................................................................... 49

49(48). Elytral interval 1 ( Fig. 1 ) extended basally to scutellum..................................................... 50

- Elytral interval 1 extended to basal margin only....................................... M. spiniferum Broun, 1880

50(49). Mesepisternum with sparse punctures................................................ M. oconnori Broun, 1912

- Mesepisternum with numerous punctures................................................................ 51

51(50). Elytral intervals 7–9 strongly convex, 7 th strial setal pattern with 3–4 setose punctures in posterior ½....... M. tuhoe sp. n.

- Elytral intervals 5–9 moderately convex, 7 th strial setal pattern with 5–7 setose punctures in posterior ½................................................................................................... M. yconomus sp. n.

Figures

FIGURE 1. Dorsal view of a Mecodema specimen showing taxonomic structures used in the species descriptions. H =head; P = pronotum; E = elytra; S = striae; I1 = interval 1; A = apex; 7S = 7 th strial setae; HSP = humerus setose puncture; HA = humeral angle; BM = basal margin; P = protibia.

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 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 9. Dorsal view of head with detail of the morphological structures used in the species descriptions. Ƒ = vertex; SPS = supraorbital puncture setae; SP = supraorbital puncture; F = frons area; FCS = frontoclypeal suture; C = clypeus; M = mandible; LS = labrum setae; L = labrum; ACM = anterior clypeal microsculpture; CSP = clypeal setose puncture; TP = tentorial pit; SG = supraorbital grooves; E = eye; ƑG = vertexal groove.

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.