Actenonyx aotearoa Kavanaugh, 2022

Kavanaugh, David H., 2022, A New Species of the New Zealand Endemic Genus Actenonyx White, 1846 (Coleoptera: Carabidae: Odacanthini) with Notes on Variation, Distribution, and Habitat, Proceedings of the California Academy of Sciences 67 (11), pp. 281-299 : 291-296

Actenonyx aotearoa Kavanaugh sp. nov.

Figures 1 B , 2 C–D , 3 B,D , 5 , 7

Type material. — Holotype, a male, deposited in NZAC, labeled: “ NEW ZEALAND, South Island , Fiordlands National Park, east end of Homer Tunnel, 23 December 1993, Stop#93-22A, D.H. & T.W. Kavanaugh col. ”/ “D. H. Kavanaugh Collection” [orange label]/ “ HOLOTYPE Actenonyx aotearoa Kavanaugh sp. nov. designated 2022” [red label]. Paratypes (a total of 22): same data as holotype (14 males and eight females; BMNH, CASC, NZAC). All paratypes also bear the following label: “PARATYPE Actenonyx aotearoa Kavanaugh sp. nov. designated 2022” [yellow label] .

Notes on nomenclature and types.— Variation among some of the specimens that I identify here as members of this new species suggests there may be more than one species represented (see discussion of variation below). Consequently, I am restricting the type series to only those specimens from the type locality. Additional sampling and subsequent study is needed to establish whether my concept of A. aotearoa represents a single species or includes two or more species. I have applied standard determination labels to all the non-type specimens to reflect my present identifications.

Type locality. — New Zealand, South Island , Fiordlands National Park, east end of Homer Tunnel, 44.76535°S / 167.98949°E, 915 m.

Derivation of species name. — The species epithet is the Maori name for New Zealand, Aoteoroa, which means “the land of the long white cloud,” a reference to the snow-covered crest of the Southern Alps as first seen from a distance at sea. It is used as a noun in apposition.

Diagnosis. — Dorsal surface of elytra without or with faint blue or blue-green metallic reflection; tooth of mentum truncate or only faintly emarginate medially; elytral silhouette subovoid ( Fig. 1B ), humeri broadly rounded, base narrowed, basal margin distinctly sinuate paramedially, discal pore punctures more distinctly foveate; abdominal sternite VI in males with one pair of apicoparamedial setae, in females with two pairs; median lobe of male genitalia ( Fig. 2 C-D) distinctly arcuate, in lateral aspect, apical lamella longer, pointed, narrowly rounded apically, and distinctly deflected right in dorsal aspect; female genitalia with tergite IX ( Fig. 3B ) short, broadly truncate, only slightly convex apically and with sclerotization/pigmentation pattern with middle transverse band and apicoparalateral arms more slender and sharply defined, apicoparalateral arms extended to apical margin and distinctly recurved laterally along the margin ( Fig. 3B ), intersegmental membrane ventrad tergite IX with short and sparse setae, ovipositor ( Fig. 3D ) with gonocoxite 2 distinctly shorter than gonocoxite 1.

Comments. — As noted above in the Comments section for A. bembidioides , virtually all of the external features noted to distinguish most members of these two species cannot distinguish all members, whether applied singly or even in combination. This confusing overlap in external morphological features is likely the main reason why the existence of at least two separate species has not been recognized previously. Because males and female of the two species recognized here are each easily distinguished on the basis of their genitalic morphology, dissection and examination of these features are recommended to confirm identifications for either sex.The description that follows includes features characteristic of specimens of the type series. Variation in these features beyond what is seen in the type series but found among specimens identified as A. aotearoa from other areas is discussed in the section on Geographical variation below.

Description.— Size small, BL males = 7.5 to 8.0 mm, females = 7.6 to 8.3 mm. Body and all appendages black. Dorsum dull to slightly shiny, without or with slight metallic blue or blue-green metallic reflection. Microsculpture on head comprised of faintly (medially on frons and vertex) to moderately (on occuput) impressed isodiameteric sculpticells, slightly stretched in wrinkled areas; pronotal microsculpture comprised of faintly impressed isodiametric sculpticells, difficult to discern in wrinkled areas; elytral microsculpture comprised of moderately impressed and regular or slightly irregular isodiametric sculpticells.

Head. Labrum truncate or slightly emarginate apically, with two or three pairs of apical setae and sparse and scattered short pubescence. Clypeus with one pair of fixed setae and very sparse and short pubescence laterally. Mandibles moderately elongate, about 1.75 times as long distance between antennal base and apical margin of labrum. Maxilla with galea comprised of two subequal galomeres and free from the lacinia; apical maxillary palpomere glabrous. Antennae with scape moderately long, slightly more than twice as long as wide, cylindrical; antennomeres 2 and 3 with much reduced pubescence compared with that of more distal antennomeres, but with at least a few sparse and scattered fine setae over their length in addition to the apical whorl of fixed setae; all antennomeres concolorous. Frons convex medially with shallow longitudinal wrinkles and very sparse and short pubescence laterally, frontal furrows poorly defined, shallow, and short. Vertex convex and smooth medially, with obliguely-longitudinal wrinkles laterally, with two or three pairs of supraorbital setae present. Eyes large, convex but only moderately projected. Tempora short, oblique. Ventral surface of each gena with a single fixed seta plus a few sparse and very short setae. Mentum: with median tooth present, truncate or slightly emarginate apically (very slightly bifid in a few specimens); suture between mentum and submentum (gula) straight and complete. Submentum with a single seta on each side.

Prothorax. Pronotum subcordate, ratio PL/PW 0.85-0.92, greatest width near anterior onefourth, narrowest at base; anterior margin straight or slightly concave; lateral margins rounded in anterior one-third, straight in basal two-thirds or slightly sinuate subapically in some specimens; basal margin straight; anterior angles rounded, not at all projected anteriorly; posterior angles rectangular or very slightly obtuse, not at all projected posteriorly; anterior margin without margination; lateral explanation (medial to lateral bead) absent; lateral bead (margination) thin, slightly elevated, extended from anterior angle posteriorly to near posterior angle then roundly continuous with lateral parts of basal margination; basal margination evident laterally but absent or obscured (by transverse wrinkles) medially; pronotal disc with shallow transverse wrinkles throughout and nearly to base, sparsely and faintly punctate peripherally, without parasagittal impressions; anterior and posterior transverse impressions moderately deep, distinct and broad, medial longitudinal impression well-defined, narrow, extended between anterior and posterior impressions only; midlateral setae absent (but see Geographical variation section below), basolateral setae absent. Proepisterna narrowly visible in dorsal view in basal two-thirds, smooth and impunctate.

Pterothorax. Elytral silhouette subovoid ( Fig. 2B ), humeri broadly rounded, base narrowed; basal margin distinctly sinuate paramedially, of uniform depth throughout; lateral explanation narrow throughout; posthumeral sinuation of lateral margin shallow but distinct in most specimens, absent from a few, subapical sinuation obsolete, elytral apices obliquely truncate; elytral topography (in cross-section) flat medially and rounded laterally; intervals slightly convex, all almost equally so; striae moderately and broadly impressed throughout, not or only faintly punctulate; parascutellar seta present on each elytron, inserted at base of stria 1, its pore socket not elevated above interval 1; discal setiferous pore punctures slightly to moderately foveate, interval 3 with three to four discal setae (two in a few specimens), the anteriormost inserted in or near stria 3 and the others in or near stria 2; interval 5 with one to seven discal setae inserted in or near interval 4; interval 7 with three to seven discal setae inserted in or near stria 6; umbilicate series comprised of ten to 13 setae arranged in three groups (four or five anterior setae, one middle seta, and five to seven posterior setae); two apical setae present (one near the apex of stria 2 and one near the apex of interval 2. Hindwings present, apparently full-sized (with a folded apex) and functional. Metepisterna about twice as long as wide.

Legs. Metacoxae bisetose, with one seta medially and one laterally at the medial end of the lateral coxal wing. Protarsomeres 1 to 3 of males distinctly broader and more robust than in females and with pads of adhesive setae ventrally, these pads absent from females, protarsomere 4 very slightly more robust in males than in females but without a pad of setae in both sexes; metatarsomeres 4 with short lateral lobes; metatarsomeres 5 with 2 rows of three lateral setae.

Abdomen. Visible sternite II with a small cluster of setae medially between the metacoxae; sternites 3 to 5 with two to seven or more pairs of paramedial setae in rows at midlength of each sternite; sternite VI apically truncate or very slightly convex, in males with one pair of apicoparamedial setae, in females with two pairs; abdominal venter with a few scattered, short, and pubescence-like setae, especially laterally and most abundant on sternite VI. Abdominal tergite VIII of both sexes narrowly divided by membranous cuticle medially into laterotergites.

Male genitalia. Laterotergites VIII with basal apodeme narrow and sclerotized margin incorporating spiracle laterally; mediotergite IX (“ring sclerite”) angulate anteriorly, wishbone-shaped. Median lobe distinctly arcuate, slightly narrowed basally, broadest near mid-length and then evenly tapered toward apex in lateral aspect ( Fig. 2D ); apical lamella long, pointed, narrowly rounded apically, and distinctly deflected right in dorsal aspect ( Fig. 2C ).

Female genitalia. Tergite IX (= mediotergite IX of Deuve (1993)) ( Fig. 3B ) broadly truncate, only slightly convex apically, sclerotization/pigmentation pattern with middle transverse band and apicoparalateral arms more slender and sharply defined, apicoparalateral arms extended to apical margin and recurved laterally along the margin ( Fig. 3B ). Intersegmental membrane ventrad tergite IX with short and sparse setae. Gonocoxite 1 of ovipositor ( Fig. 3D ) with a fringe of four to seven apicoventral setiform setae and with basal apodeme as in Fig. 3D . Gonocoxite 2, shorter than gonocoxite 1, falciform, acuminate and narrowly rounded apically, with two lateral ensiform setae and one dorsal ensiform seta. Bursa copulatrix ( Fig. 3D ) membranous, asymmetrically vase-like, with narrower extension to common oviduct and spermathecal assembly, without evident spicules; common oviduct short, attached to bursa proximal to spermathecal assembly; spermathecal assembly with basal bulb narrowly joined by a duct to spermathecal sclerite, spermathecal gland reservoir inserted apically on basal bulb and elongate-ovoid.

Geographical variation. — The size range among all specimens that I have identified as A. aotearoa is slightly broader (BL males = 6.8 to 8.0 mm, females = 6.5 to 8.8 mm) than that of the type series (BL males = 7.5 to 8.0 mm, females = 7.6 to 8.3 mm). Both the smallest and the largest specimens examined were collected on North Island, with the largest specimens from the Tairua area and the smallest specimens from the Ohakune, Wainuiomata, and Wellington areas. Most surprising was the discovery of specimens with a lateral seta present on each side at or near the apical one-third of the pronotum, inserted partly in the narrow groove just inside the lateral bead and partly on the lateral bead itself. The absence of such setae has been considered a characteristic feature of Actenonxy members; and I have not seen any specimen of A. bembidioides with these setae present nor are they present in any specimen of type series of A. aotearoa . In material that I examined, the occurrence of specimens with these pronotal setae was restricted to localities in the southern part of North Island and one locality on the northern end of South Island (see Fig.5 ). Although sample sizes were small, all specimens examined from these localities had these setae, and no specimens outside of these areas on either island had them. The presence of the lateral pronotal setal also appears to be correlated with smaller size, at least in the material that I examined. However, as far as I could determine, males and females of all sizes and with or without the pronotal setae share similar genitalia, respectively. Consequently, I have found no basis upon which to recognize more than a single new species, A. aotearoa , at this time. Additional distinguishing features may become apparent with stategic sampling and additional material, particularly from North Island and the northern part of South Island.

Geographical distribution. — This species is apparently widely distributed in mountainous parts of both North and South Islands. I examined a total of 72 specimens (36 males and 34 females), including the type series, from the following localities ( Fig. 5 ): NORTH ISLAND. Coromandel: Tairua (May 1876; two females, BMNH) . Taupo: Ohakune (1 October 1919, T.R. Harris collector; one male, BMNH), (December 1922, T.R. Harris collector; two males, BMNH), (December, 1919, T.R. Harris collector; one male, NMNH) . Wanganui: Rangitikei River (near Porewa , March 1941, S. Gibbs collector; one female, BMNH) . Wellington: Wainuiomata (16 October 1919 H.V. Hudson collector; one male and one female, BMNH) ; Wellington (Hudson collector; one female, BMNH), (1891, Hudson collector; three males and three females, BMNH), (one male, BMNH) . SOUTH ISLAND. Buller: Boatman’s Creek (near Reefton; one female, BMNH) ; Kumara (1884, Helms collector; one male, BMNH) ; Lake Guyon (two males, BMNH) . Fiordland: Fiordland National Park, Cleddau River (at Milford Sound , 9 December 1995, W.W. Middlekauff collector; one male CASC) , Homer Tunnel (east end, 915 m, 23 December 1993, D.H. and T.W. Kavanaugh collectors; 15 males and eight females, BMNH, CASC, NZAC) ; Te Anau (19 November 1991, G. Mathieson collector; one female, CASC) . Marlborough: Hanmer Springs (13 November 1986, J.G. Edwards collector: one female, CASC) . Mid Canterbury: Arthur’s Pass (910 m, 4 January. 1923, Myer collector; one female, BMNH), (3 January 1943, C. E. Clarke collector; one male, BMNH), (1 January 1943, C. E. Clarke collector; one female, BMNH), (1 January 1943, E.S. Gourlay collector; one female, CASC) ; Arthur’s Pass National Park ( Klondyke Corner , 645m, 27 December 1993, D.H. Kavanaugh collector; one male, CASC) ; Bealey (620 m, 27 December 1993, D.H. Kavanaugh collector; one male, CASC) ; Cass area (910 m, 7 September 1972, C.W. Sabrosky; one female, NMNH) ; Mount Hutt (December 1911; one male, BMNH) . Nelson: Abel Tasman National Park ( Marahau , 26 January 1995, H. Fischer collector; one female, RSCC) ; Westport (November-December 1901, J.J. Walker collector; one male and one female, BMNH) . Otago Lakes: Lake Wanaka (5 January 1949, B. Davidson collector; one male, BMNH) . South Canterbury: Lake Tekapo (one female, BMNH) . Westland: Otira (20 February 1919, J.W.Campbell collector; two females, NMNH) ; Otira River (at Pegler Creek , 3 January 1943, C.E. Clarke; one male, BMNH) . LOCALITY UNKNOWN. (G.V. Hudson collector; one male and one female, BMNH); (J.J. Walker collector; two females, BMHN); (Suter collector; two males, BMNH); (one males and three females, BMNH); (C.M. Wakefield collector; one male and one female, BMNH); (T. Broun collector; one female, BMNH) ; (one female, NMNH) .

Habitat distribution. — Specimens of the type series were all collected under stones at the edges of a small snowmelt stream ( Fig. 7B ) above treeline at an elevation of 915 m. This area was at the base of the east-facing slope of a U-shaped (previously glaciated) valley ( Fig. 7A ) running north-south on the eastern flank of the Southern Alps. Two additional specimens were collected in the Arthur’s Pass area, one under a stone on a broad, flat, braided river bank at Klondyke Corner (elev. 645 m) and the other under a loose stone in a concrete drainage ditch at Bealey (620 m). All of the other locality records listed above were without associated elevational and/or habitat data, so both the elevational and habitat ranges of this species are still only poorly known and require additional study.

Geographical relationships with related species. — The geographical range of A. aotearoa as described here overlaps broadly with that of A. bembidoides in mountainous parts of both North and South Islands. See this section in the treatment of the latter species above for details.

Figures

FIGURE 1. Dorsal habitus of Actenonyx species. A. A. bembidioides White (South Island, Southland, Te Anau Downs, Mistletoe Creek, 216 m); B. A. aotearoa sp. nov. (South Island, Fiordlands National Park, east end of Homer Tunnel, 915m). Scale lines = 1.0 mm.

FIGURE 2. Male genitalia of Actenonyx species. A and B. A. bembidioides White (South Island, Southland, Te Anau Downs, Mistletoe Creek, 216 m); C and D. A. aotearoa sp. nov. (South Island, Fiordlands National Park, east end of Homer Tunnel, 915m). A and C. Dorsal aspect; B and D. Left lateral aspect. Scale line = 0.5 mm.

FIGURE 3. Female genitalia and reproductive tract. A and C. A. bembidioides White (South Island, Southland, Te Anau Downs, Mistletoe Creek, 216 m); B and D. A. aotearoa sp. nov. (South Island, Fiordlands National Park, east end of Homer Tunnel, 915m); A and B. Tergite IX, dorsal aspect; C and D. Genital capsule and reproductive tract; bc = bursa copulatrix; co = common oviduct; gc1 = gonocoxite 1; gc2 = gonocoxite 2; sbb = spermathecal basal bulb; sg = spermathecal gland; sgd =spermathecal gland duct. Scale lines = 0.5 mm.

FIGURE 5. Map showing distribution records for specimens of Actenonyx aotearoa sp. nov. examined for this study (red circle = type locality; blue circles = localities where specimens have pronotal lateral setae; black circles = other localities). Scale line = 200 km.

FIGURE 7. Photographs of habitat for Actenonyx aotearoa sp. nov. A. Glaciated valley at east end of Homer Tunnel, Fiordlands National Park, South Island, view looking north; B. Snowmelt streams at east end of Homer Tunnel, just south of tunnel entrance.