Creophilus rekohuensis, 2011

Clarke, Dave J., 2011, Testing the phylogenetic utility of morphological character systems, with a revision of Creophilus Leach (Coleoptera: Staphylinidae), Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 163 (3), pp. 723-812 : 796-799

12. CREOPHILUS REKOHUENSIS CLARKE SP. NOV.

( FIGS 1D, 33C, F, I, K, L, P, Q , 36 , 37 )

Type material: Holotype. ♂, ‘ NEW ZEALAND: Chatham| Is. Rangatira I. Nature| Res., Woolshed Bush,| Woolshed Bush Trk., 30 m,| 44 °20.45′S, 176 °10.58′W,/ 9–14.ii.2006, coastal| broadleaf forest (Myrsine-| Pseudopanax - Coprosma );| seabird burrow entrance &/ ground at night,| D.J. Clarke & M. Renner;| site DC0015, 95%ethanol| FIELD MUS. NAT. HIST./ FMNH-INS 0000 019 462/ HOLOTYPE | Creophilus | rekohuensis Clarke sp. nov. | designated by D.J. Clarke 2008’ (in LUNZ). Left wing dissected and mounted on card, aedeagus and genital segment dissected, stored in glycerin in genitalia vial mounted with specimen. Paratypes (22). Unless otherwise stated, the left wing, aedeagus and genital segments of males are dissected and mounted with the specimen. All pinned specimens and alcohol lots with label ‘ PARATYPE | Creophilus | rekohuensis Clarke sp. nov. | designated by D.J. Clarke 2008’: 6 specimens, same data as holotype: 3♂, 1♀, pinned, [♂ ’s, FMNH-INS 0000 019 463–465]; [♀, FMNH-INS 0000 019 466]; 2 specimens in 70% alcohol, 1♂, genitalia dissected, with specimen, ‘FMNH-INS 0000 019 467’; 1♀, genitalia dissected, with specimen, ‘FMNH-INS 0000 019 468’ (in FMNH; 1♂ in NZAC). 1♀, on card, ‘Chatham| Islds./ A.E. Brookes| Collection/ FMNH-INS 0000 012 565’ (in NZAC). 1♀, leg segments on card ‘Mangere I. [44 °15′S 176 °18′W]| Chatham Islands.| 4–21 Jan., 1924.| Coll. C. Lindsay/ Staphylinus sp. / FMNH-INS 0000 017 670’ (in CMNZ). 2 specimens, ‘ NEW ZEALAND, CH | Mangere I [44 °15′S 176 °18′W]| 28.x.1993 | R.M. Emberson| in petrel burrow entrance’: ♂, right mesotarsal claw on card ‘FMNH-INS 0000 012 560’; ♀, ‘FMNH-INS 0000 012 561’ (in LUNZ). 1♀, macerated, in 70% alcohol, both wings dissected, ‘ NEW ZEALAND, CH | Pitt Island,| Preece Covenant Bush [44 °16′55″S 176 °10′45″W]| 18.i.1998 J.W.M. Marris| under rotten log/ FMNH-INS 0000 012 567’ (in LUNZ). 1♀, ‘CHATHAM IS, N.Z.| Pitt Island, 100 m | Rangiauria Res [44 °19′32″S 176 °15′46″W]| 22.xi.1992 | J.W. Early/ Under rock on| Sarcocornia -| Disphyma papillatum | sward/ AMNZ 11132| AUCKLAND | MUSEUM| NEW ZEALAND’ (in AMNZ). 1♀, on point, ‘Rabbit Is [44 °14′28″S 176 °16′55″W]| Chatham Is.| M.A. Ritchie| 7.VIII.68/ FMNH-INS 0000 017 672’ (in CMNZ). 1♀, missing front and hind legs, terminal abdominal segments and left elytra on card, ‘on ground| South East I. [Rangatira I.]| Chatham Is.| 27 Dec. 1937 | E.G. Turbott/ AMNZ 11133| AUCKLAND | MUSEUM| NEW ZEALAND’ (in AMNZ). 1♂, ‘ NEW ZEALAND, CI| Rangatira| 27–30.xi.1992 | J.W. Early R.M. Emberson| P. Syrett pitfall traps/ FMNH-INS 0000 012 564’ (in LUNZ). 1♀, ‘ NEW ZEALAND, CI| Rangatira| 28.xi.1992 | P. Syrett| under log/ FMNH- INS 0000 017 639’ (in LUNZ). 1♂, not dissected, in 95% alcohol, ‘ NEW ZEALAND: Chatham Is.| Rangatira I. Nature Res., Top Bush,| Old Forest Rd. Trk., 90 m, 44 °20.87′S,| 176 °10.5′W, 9–14.ii.2006, coastal| broadleaf forest ( Myrsine -| Pseudopanax-Coprosma);| FMHD#2006–048, carrion traps| (squid; live x5), D.J. Clarke & M.| Renner; site DC0017, 95% ethanol| FIELD MUSEUM NAT. HIST./ FMNH-INS 0000 019 461’ (in FMNH). 1♂, macerated, in 70% alcohol, dissected, both wings dissected, ‘ NEW ZEALAND, CI| South East Island [Rangatira I.],| Kokapu Creek [44 °20′50″S 176 °10′10″W]| 15.i.1997 J.W.M Marris| under rock by creek/ FMNH- INS 0000 012 566’ (in LUNZ). 1♂, aedeagus not dissected, ‘ NEW ZEALAND, CI| South East I., [Rangatira I.]| Woolshed Bush [44 °20′S 176 °10′W]| 13–17.i.1997 | R.M. Emberson, J.W. Marris/ pitfall traps in coastal| broadleaf forest/ FMNH-INS 0000 012 562’ (in LUNZ). 1♂, same as preceding specimen but with date ‘ 19–21.i.1998 ’ [county as ‘CH’] and ‘FMNH-INS 0000 012 563’ (in LUNZ). 1♂, ‘ NEW ZEALAND, CI| South East I., Woolshed| Bush- Whalers Bay Track [44 °20′22″S 176 °10′28″W]| 18.i.1997 J.W.M. Marris| on trees and logs at night/ FMNH-INS 0000 012 559’ (in LUNZ). 1♂, ‘ NEW ZEALAND, CH | Star Keys [44 °15′S 176 °0′W]| 23.i.1998 | R.M. Emberson| under rocks/ FMNH-INS 0000 012 558’ (in LUNZ).

Description of type locality: Woolshed Bush, northern end of island, <200 m south of Department of Conservation Hut, along track. Habitat: sparse regenerating coastal broadleaf forest with mixed Myrsine , Pseudopanax , and Coprosma trees dominant. Understorey sparse to open, ground with high density of diving petrel burrows, leaf litter scant, ground layer mostly compacted soil.

Diagnosis: With characters of the erythrocephalus - group; postgena pale yellowish to reddish-brown, distinct from blackish-brown of rest of body; apex of antennomere 11 asymmetrically produced ( Fig. 36B ); brachypterous ( Fig. 33P, Q ); last protarsomere distinctly shorter than preceding two together ( Fig. 36G ); elytral discal series with two macrosetae; tergal chaetotaxic formula = 4-6-6-6- 4(6)-6.

Description: Measurements (N = 10♂, 8♀). Forebody length: ♂ 5.3–6.8 mm, ♀ 5.6–6.2 mm. See supporting Table S5 for comparison of ranges of male and female ratios. Head. Head ( Fig. 33C ) brownish-black dorsally ( Fig. 1D), postgena yellowish to reddish-brown; strongly trapezoidal in both sexes, much wider posteriorly; HW/HL = 1.44–1.63; hind angles distinctly rounded; shining, without distinct microsculpture; ventrolateral carina absent in all males seen; eyes moderately large (EYL/HL = 0.41–0.50), dorsolateral, lateral margins of head visible in dorsal view (not obscured by eye); HL1/HL2 slightly larger in females than males, or subequal (♂ = 1.38–2.20, ♀ = 1.67– 2.17); antennae as in Figure 36B , subclavate, antennomeres 1–6 brown-black, 7–11 lighter reddish-brown, 11 distinctive, without apical ridge, asymmetrically produced to anterior subconical point, much shorter than 9–10 together; each apical pair of setae close together on anterior subconical point; mandibles as in Figure 36A , subequal to head in males and females (ML/HL ♂ = 1.00–1.06, ♀ = 0.88– 1.12), right mandible with three teeth, T3 largest, T1 and T2 usually reduced; left mandible with distal tooth strongly projecting from base of mandibular blade, ventral basolateral ridge weakly developed. Thorax and abdomen. Pronotum ( Figs 33F , 36H ) slightly transverse (PW/PL = 1.07–1.19); distinctly longer than elytral suture (PL 1.59–1.87 ¥ ESL); with basolateral margins very slightly emarginate, hind angles indistinct; disc with sparse peripheral setae and short, sparse vestiture on anterolateral declivities; elytra subquadrate, width subequal to or slightly narrower than pronotum, uniformly blackish-brown, sparsely setose, and rugosely sculptured, especially on humeri; brachypterous, wings short ( Fig. 33P, Q ), non-functional, clear yellowish-brown, without black spot in medial field between MP3 and MP4 veins; mesoventral intercoxal process acutely angulate, usually distinctly V-shaped ( Fig. 33I ); metaventrite broadly flattened, with small posteromedial tumescence near hind margin; protibiae ( Fig. 36J ) frequently without outer row of spines, when present with 1–3 very reduced tubercles (much shorter than accompanying bristles), and rarely with equal number on both protibiae; last protarsomere subequal in length to preceding two together, or shorter ( Fig. 36G ); abdomen blackish-brown, each segment lighter apically ( Fig. 1D); vestiture sparse, brownishblack; tergite VII with at most poorly developed palisade fringe. Male genitalia. Aedeagus as in Figure 36E and F ; with basal and apical subtriangular membranous regions ventrally ( Fig. 36E, K , stm), with paired apicolateral sclerites (as) fused to lateral edge of median orifice; with narrowly acuminate apex ( Fig. 36K ). Paramere as in Figure 36D , usually with sides subparallel, widest before apex. Internal sac inverted as in Figure 36E and F . Female internal genitalia. Internal female genitalia as in Figure 36I ; vaginal plate (vp) with paired lateral sclerites (pls), with posterolateral aspects membranous; vaginal fold (vf) with single narrow sclerite dorsal to apex of vaginal plate ( Fig. 36I , vf). Chaetotaxy. Macrosetae unusually long; elytral discal series with two macrosetae, protrochanter with two macrosetae, mesotrochanter with one macroseta; tergal chaetotaxic formula = 4-6-6-6-4(6)-6; medial macrosetae absent from tergite III, inner lateral macrosetae present or absent on tergite VII.

Variation: Several paratypes have the transverse basal ridge of tergites III – V variously effaced or very faint. A few specimens are teratological, having deformed heads or pronota .

Comparison: Emberson (1998) recorded C. rekohuensis as a new, undescribed species but noted it may be identical to C. huttoni . It is best distinguished from other New Zealand species by the strongly trapezoidal head, asymmetrically produced terminal antennomere ( Fig. 36B ), and unusually shortened terminal protarsomeres ( Fig. 36G ; unique in Creophilus ). Two further significant differences between C. rekohuensis and all other Creophilus species are (1) apparent sexual monomorphism, and (2) the acutely angulate mesoventral intercoxal process. Although the sample size is small, available males and females were rather consistent in size.

Distribution ( Fig. 37 ): Chatham Islands ( New Zealand): Pitt, Rangatira, Mangere, Star Keys, and Rabbit Islands. Extensive carrion trapping on Pitt and Chatham Islands (27 January to 6 March 2006) was unsuccessful in collecting this species. Remaining seabird nesting colonies are the most likely habitat, particularly in large areas of relatively intact native vegetation such as Tuku Nature Reserve, where there is also rodent control around taiko ( Pterodroma magentae Giglioli and Salvadori ) burrow groups.

Biology and ecology: Collection data indicate C. rekohuensis is nocturnal and active on the ground, but rarely found at carrion (only one specimen). However, as far as I know carrion trapping had not been attempted before in the Chatham Islands. Trapping on Rangatira Island was thwarted by large numbers of raphidophorid crickets that probably deterred the beetles, and also quickly consumed much of the bait, thereby reducing its effectiveness as an attractant. Further trapping should utilize much larger and better protected baits. Habitat: coastal broadleaf forest (mixed Myrsine – Pseudopanax – Coprosma ) and coastal herb fields ( Sarcocornia – Disphyma ). Altitude: 30– 100 m. Phenology: January–February, August, October–December. Light exposure induces a flight response in which the wings are extended while running (pers. observ.). The shortened wings are, however, non-functional. Wing folding is aided by repeated curling and telescoping of the abdomen, which brings the apex of the seventh tergite into Chathams-endemic flightless beetles ( McGuinness, 2001), its rarity, probable vulnerability to rodent predation, and possible restriction to the smaller islands suggests it may require formal conservation status.

Etymology: The species epithet ‘ rekohuensis ’ is derived from a combination of Rekohu and the Latin adjectival suffix -ensis, meaning ‘belonging to’, in reference to the species being endemic to the Chatham Islands. Rekohu is the moriori name for Chatham Island, meaning ‘misty skies’, and refers to the seemingly perennial cloud cover shrouding these islands. This name was chosen in honour of the moriori people, the original inhabitants of the Chatham Islands.

Remarks: The earliest record for C. rekohuensis is a female specimen collected by C. Lindsay on Mangere Island in 1924, and it was recorded by Brookes (1925) as one of two possibly new species of Staphylinus , along with Quedius antipodum .

contact with the wing surface. Usually several folding attempts are made, but even then at least one wing often remains partly extended. Specimens were observed feeding on maggots supplied to them with rotting fish. A few specimens discharged an unpleasant smelling white substance from the abdomen when threatened.

This new species is morphologically and ecologically unique within Creophilus and more detailed ecological studies are warranted. Like several other

Figures

Figure 33. New Zealand Creophilus species, details of morphology (setae of heads, pronota, mesoventrites, and legs omitted). C. oculatus (A, D, G, J, M, N); C. huttoni (B, E, H, O); C. rekohuensis, holotype (C, F, I, K, L, P). A–C, head, dorsal; D–F, pronotum; G–I, mesoventrite; J, K, protarsus, dorsal; L, M, right protibia, anterior; N–P, left wing, dorsal; Q, scatter plot of wing length vs. pronotum length as proxy for body size (circles = C. oculatus, squares = C. huttoni, triangles = C. rekohuensis; black symbols = males, white symbols = females). Abbreviations: CuA, MP3, MP4, wing veins mentioned in text. Scale bars = 1 mm.

Figure 36. Creophilus rekohuensis, details of morphology (A, B, D–H, J, K = holotype; setae of mandibles, antenna, pronotum, and legs omitted). A, mandibles, dorsal (bases omitted); B, right antenna, dorsal (only apical setae shown); C, ventral sclerite of internal sac, ventral (lower) and apical (upper); D, paramere, dorsal; E, aedeagus with details of inverted internal sac, ventral; F, same, right lateral (parameral setae omitted); G, protarsus, dorsal; H, pronotum; I, female internal genitalia, ventral; J, right protibia, anterior; K, median lobe apex, ventral. Abbreviations: T1, T2, T3, mandibular teeth. Additional abbreviations as in Figure 3 (male) and Figure 5 (female). Scale bars: C = 0.1 mm; rest = 1 mm.

Figure 37. Distribution of georeferenced specimens of C. rekohuensis in the Chatham Islands, New Zealand (circles). The four largest islands from west to east are Little Mangere, Mangere, Pitt, and Rangatira. The record off the north-west coast of Pitt Island is from the tiny Rabbit Island. This species is also known from Star Keys, 14.5 km east of Pitt Island. For location of Chatham Islands see Figure 34.