Mecodema pluto Britton, 1949

Seldon, David S. & Leschen, Richard A. B., 2011, Revision of the Mecodema curvidens species group (Coleoptera: Carabidae: Broscini), Zootaxa 2829, pp. 1-45 : 35-36

Mecodema pluto Britton, 1949 (redescription)

Figures: 5, 6b, 7b, 12b, 16a, 25.

Mecodema pluto Britton, 1949: 576 .

Diagnosis. Head and body convex. Clypeus with a single setose puncture on each side bearing 2 setae. Prothoracic carina narrow, crenulated and extended to anterior angle. Pronotum fovea deep and broad. Elytral striae with small regularly distributed asetose punctures. Setose punctures absent on 3rd, 4th and 5th ventrites. Apical portion of aedeagus symmetrically rounded with a moderate twist to right of vertical axis. Dorso-apical portion of central spicule, greatly expanded. Basal lobe of left paramere rectangular, arm medium and apical lobe relatively small, with setation along apical ¾ of ventral edge.

Description. Length 16–22 mm. Colour black. Head and body convex. Microsculpture of frons and vertex absent. Vertexal groove shallow laterally, narrow and defined middle. Form of microsculpture on anterior area of clypeus, sulcate, clypeus with a single setose puncture bearing 2 setae. Form of lobes of the mentum, square. Submentum constriction broad, with greater than or equal to 6 setae. Prothoracic carina narrow, crenulated and extended to anterior angle. Pronotum broad but convex, posterior lateral sinuation angle parallel or slightly angled outward. Pronotal fovea deep and broad, rugose microsculpture may be present laterally on pronotal disc. Elytra narrow and highly convex, striae with small regularly distributed asetose punctures. A single setose puncture present on mesocoxa, absent on metacoxa. Setose punctures of 3rd, 4th and 5th ventrites absent. Apical portion of aedeagus symmetrically rounded with a moderate twist to right of vertical axis. Dorso-apical portion of central spicule, greatly expanded. Left paramere basal lobe rectangular, arm medium and apical lobe relatively small, with setation along apical ¾ of ventral edge.

Comments. This species was named for one specimen from Te Aroha described by Britton (1949). The specimen is in poor condition, and missing the right maxillary palpus, antennomeres 2–11 from the right antenna and antennomeres 5–11 from the left antenna. The type locality for this species is the summit of Mt Te Aroha, Waikato. However, six years (2004–2010) of continuous pitfall trapping has failed to catch additional specimens of M. pluto on or near the summit of Mt Te Aroha. Anecdotal collecting evidence suggests that this species is associated with kohekohe ( Dysoxylum spectabile ) forest on the mid to lower slopes of the mountain and found rarely in the cloud forest around the summit.

Distribution. North Island: Coromandel Ranges (CL) and northern Kaimai Range (BP), Type Locality: Mt Te Aroha summit.

Holotype: ( BMNH) card mounted, Te Aroha Trig. Stn. 1001. [hw] Type (round label with red border) glued on card / 1200 (light blue label glued on card) / Te Aroha N. Zealand. H. Swale. 1913–117. (broad pink line below collector name) / HOLOTYPE Mecodema pluto n. sp. [hw] E. B. Britton det. 6.11.1945 [hw].

Other material examined: CL: 1, Tapu Hill Coromandel Range 1979 M. Miller ( AMNZ); 1, Mt Te Aroha summit 2002 S.E. Thorpe ( AMNZ); 1, Coromandel Mtns 1934 C.E. Clarke ( AMNZ); 2, Tapu Hill 1960 J.I. Townsend & R. Zonders ( NZAC); 2, Kennedy Bush Block 1993 Larivière Larochelle ( NZAC); 2, Otama F.P. 1993 Larivière Larochelle ( NZAC); 1, Kaueranga Vly 1993 Larivière Larochelle ( NZAC); 7, Maumaupaki Tk 1993 Larivière Larochelle ( NZAC); 1, Waikawau Bay 1978 R.M. Emberson ( LUNZ); 1, Waikawau Bay 1978 C.T. Jamin ( LUNZ).