Amychus manawatawhi, Marris & Johnson, 2010

Marris, John W. M. & Johnson, Paul J., 2010, A revision of the New Zealand click beetle genus Amychus Pascoe 1876 (Coleoptera: Elateridae: Denticollinae): with a description of a new species from the Three Kings Islands, Zootaxa 2331 (2331), pp. 35-56 : 47-49

Amychus manawatawhi , sp. nov.

( Figs. 3, 6, 9–11, 20–26)

Adult material examined. Holotype. ♂. “ New Zealand, TH [Three Kings Islands], Great Island, Lighthouse Bush, NZMS 260 LO 1 316827, 5.xii.1996, J.W.M. Marris, on Kunzea trunk at night / HOLOTYPE ♂ Amychus manawatawhi Marris & Johnson 2010 [Red label]” [Dissected, genitalia vial attached to pin] [specimen length 22.5 mm] ( LUNZ). Paratypes. New Zealand, Three Kings Islands: Great Island, New Zealand, TH, Great Island, Tasman Valley, NZMS 260 LO 1 316823, 9 December 1996, J.W.M. Marris, on trees and logs at night (8 sex unknown, AMNZ, BMNH, CMNZ, MONZ); New Zealand, TH, Great Island, Tasman Valley, NZMS 260 LO 1 316823, 9 December 1996, J.W.M. Marris, on tree at night (1 ♂, 2 sex unknown, LUNZ); New Zealand, TH, Great Island, Tasman Valley, NZMS 260 LO 1 316823, 9 December 1996, J.W.M. Marris, on Kunzea trunk at night (3 ♀, 1 sex unknown, LUNZ); New Zealand, TH, Great Island, Lighthouse Bush, NZMS 260 LO 1 316827, 7 December 1996, J.W.M. Marris, on Kunzea trunk at night (1 ♂, 2 ♀, LUNZ); New Zealand, TH Great Island, Tasman Valley NZMS 260 LO 1 316823 7 December 1996 J.W.M. Marris, in dead, standing Kunzea tree (1 sex unknown, LUNZ); New Zealand, TH, Great Island, Lighthouse Bush, NZMS 260 LO 1 316827, 7 December 1996, G.L.F. Carlin, on Kunzea trunk at night (1 sex unknown, LUNZ); New Zealand, TH, Great Island, Tasman Valley NZMS 260 LO 1 316823, 7 December 1996, G.L.F. Carlin, under loose bark of Kunzea tree (1 sex unknown, LUNZ); New Zealand, TH, Great Island, Lighthouse Bush, NZMS 260 LO 1 316827, 5 December 1996, J.W.M. Marris, on Kunzea trunk at night (1 ♂, 3 sex unknown, LUNZ); New Zealand, TH, Great Island, Lighthouse Bush, NZMS 260 LO 1 316827, 6 December 1996, J.W.M. Marris, on Kunzea trunk at night (1 sex unknown, LUNZ); New Zealand, TH, Great Island, Tasman Valley, NZMS 260 LO 1 316823, 10 December 1996, J.W.M. Marris, under stones and loose bark Kunzea /broadleaved forest (1 ♂, 1 sex unknown, LUNZ); New Zealand, TH, Great Island, South East Bay Bush, NZMS 260 LO 1 324833, 9 December 1996, F.J. Brook, under Cordyline log (1 sex unknown, LUNZ); New Zealand TH, Great I, Tasman Stream, 7 November 1999, F.J. Brook, on kanuka [ Kunzea sinclairii ] at night (1 ♂, 1 ♀, AMNZ); New Zealand, TH, Great Island, Baylis Stream, 11 April, M.J. Thorsen, on kanuka [ Kunzea sinclairii ] at night (1 ♂, 1 sex unknown, LUNZ); New Zealand, TH, Great Island, Baylis Stream, 11 April, F.J.Brook, on kanuka [ Kunzea sinclairii ] at night (1 sex unknown, LUNZ); Three Kings Islands, N[ew] Z[ealand], Great Island, 45 m, South East Bay, 27 November–1 December 1983, J.C. Watt, Pit trap 83/136 (3 sex unknown, NZAC); Castaway Camp, Three Kings Islands, Great Is[land], November [19]70, N[ew] Z[ealand] Ent[omology] Div[ision] Exp[edition], J.C. Watt (4 sex unknown, NZAC); Tasman Valley, Three Kings Islands, Great Is[land], November [19]70, N[ew] Z[ealand] Ent[omology] Div[ision] Exp[edition], J.C. Watt, under bark Leptospernum ericoides [= Kunzea sinclairii ] (4 sex unknown, NZAC); Tasman Valley, Three Kings Islands, Great Is[land], November [19]70, N[ew] Z[ealand] Ent[omology] Div[ision] Exp[edition], J.C. Watt, under bark Leptospernum ericoides [= Kunzea sinclairii ], Illustrated J. Liddiard 14 February [19]92 (1 sex unknown, NZAC); Tasman Valley, Three Kings Islands, Great Is[land], November [19]70, N[ew] Z[ealand] Ent[omology] Div[ision] Exp[edition], G. Kuschel (3 ♂, 6 ♀, 7 sex unknown, NZAC); Tasman Valley, Three Kings Islands, Great Is[land], November [19]70, N[ew] Z[ealand] Ent[omology] Div[ision] Exp[edition], G. Kuschel, litter (1 ♀, NZAC); Tasman V, Great Is, Three Kings Is, P. Johns, 14.12.[19]63, at night (1♂, 1♀, CMNZ); South West Island: New Zealand, TH, South West Island, 29 November 1997, F.J. Brook, P. Aderson, on Meryta and Cordyline trunks at night (2 ♂, 2 sex unknown, LUNZ).

Larval Material Examined. New Zealand, Three Kings Islands: South West I., Three Kings Is., 1.iii.1949, G.A. Buddle (1, AMNZ) .

Adult diagnosis. Known only from the Three Kings Islands. Distinguished from other Amychus species by the following combination of characters: dorsum lacking glossy pustules (occasionally with a few faintly raised glossy pustules restricted to prothorax); prothorax strongly explanate; elytra flattened mesally, lateral ½ sloping obliquely to sides at midlength; hind wings brachypterous, reaching apex of elytra.

Adult description. As for the generic description and as follows. Form. Body ( Fig. 3) length (excluding head) 16.1–24.2 (x =20.5) mm, width 5.7–8.9 (x =7.4) mm (n =20 for all measurements given for this species unless stated otherwise), moderately flattened. Integument of dorsum with, at most, a few faintly visible, glossy pustules on pronotum, absent on head and elytra. Vestiture of dorsum stout, golden.

Head. Head ( Fig. 20) without pustules; vestiture stout; EI 0.23–0.31 (x =0.26). Mandibles, antennae, maxillae and labium as in Figs. 21, 24–26.

Thorax. Prothorax broad, PI 73–83 (x =77), strongly explanate; sides weakly curved to base of hind angles, widest at about posterior 2/3 rd and near apex of hind angles, hind angles parallel-sided to weakly divergent; disc flattened. Hypomeron with faint punctation. Prosternum with anterior chin piece separated from basal section by a faint transverse sulcus or sulcus obsolete; chin piece weakly deflexed ventrally. Prosternal spine ( Fig. 22) length 1.5–1.7 (x =1.6) (n =12) x procoxal cavity width. Scutellum with sides parallel-sided to weakly concave anteriorly. Elytra length 11.7–17.9 (x =15.0) mm; sides curved to apex, apex narrowly rounded; flattened mesally, lateral ½ sloping obliquely to sides from behind humerus to about midpoint; surface lacking sculpturation except for postbasal tubercle present on 4 th interval; striae impressed; intervals flattened to weakly convex; integument without glossy pustules. Hind wing brachypterous; length 13.8–15.6 (x =14.7) mm (n =5), depth 4.6–5.3 (x =4.9) mm (n =5); wedge cell absent; apex of wing without sclerotisations; without transverse apical fold in repose; venation as in Fig. 6; venation varies as described for the genus.

Abdomen. Abdominal ventrites punctate throughout.

Male genitalia. Aedeagus ( Fig. 9) length 2.9–3.2 (x =3.0) mm (n =10), width 0.6–0.7 (x =0.6) mm (n =10), 4.3–5.3 x as long as wide.

Female genitalia. Ovipositor ( Fig. 10) length 5.5–6.0 (x =5.7) mm (n =5); coxite length 1.2 mm (n =5); styli length 0.18–0.20 (x =0.18) mm (n =5). Genital tract ( Fig. 11) as given for generic description.

Larval description. As for the genus description and as follows. Length ca. 30.8 mm (late last instar); head with frons narrowly pedunculate posteriorly, posterior frontal arms of sutures shallowly and evenly arcuate; abdomen with terga 1–8 with deep and moderately coarse punctures, on terga 1–7 each puncture adjacent to a transversely undulating, moderately sclerotized carinula that partially forms the puncture margin; punctures extending to near posterior margin of tergite, but carinulae becoming obsolescent at posterior third on terga 7–8; tergite 9 with dorsolateral tubercles with anterior pair elevated, distinct.

Distribution. Restricted to the Three Kings Islands group (TH): Great Island (34°10´S, 172°08´E) and South West Island (34°11´S, 172°04´E).

Biology. Adults have been collected from on tree trunks (including Cordyline kaspar W.R.B. Oliver , Kunzea sinclairii (Kirk) W. Harris and Meryta sinclairii (Hook. f) Seem.) and logs at night and, by day, from under bark, stones and logs, and from pitfall traps and litter samples. The larva of A. manawatawhi is known from a single specimen from South West Island. No habitat information was given in the label data.

Remarks. The Three Kings Islands support a large number of endemic taxa including several genera and species of beetles (e.g., Britton 1964; Given 1954; Holloway 1963, 1982; Watt et al. 2001). The high number of endemics reflects the islands’ long period of isolation, since at least the late Miocene ( Brook and Thrasher 1991). Amychus manawatawhi is presumed to be a primary endemic species, that is, naturally restricted to the Three Kings Islands. If this species was a secondary endemic, that is, restricted to relict populations due to predator-induced extinction, populations would be expected to exist on other predator-free northern offshore islands. A probable example of a secondary endemic is the large entimine weevil Anagotus turbotti (Spiller) , known from the Three Kings, Hen and Chicken and Poor Knights Islands.

Molloy and Davis (1994) listed this species in category I, that is, species about which little is known, but based on existing knowledge are considered to be under threat. Hitchmough et al. (2007) placed A. manawatahi (listed as Amychus sp. ) in the Range Restricted category of the New Zealand Threat Classification System.

Etymology. The specific epithet is named for Manawa Tawhi, the Maori name for Great Island, the main island of the Three Kings group. Manawa Tawhi translates as “panting breath”. According to Aopuri Maori, the chief Rauru swam from the mainland to the Three Kings Islands and arrived exhausted and much out of breath ( Cheeseman 1888).