Agnosthaetus heteromastax Clarke, 2011

Clarke, Dave J., 2011, A Revision of the New Zealand Endemic Rove Beetle Genus Agnosthaetus Bernhauer (Coleoptera: Staphylinidae), The Coleopterists Bulletin (mo 10) 2011, pp. 1-118 : 31-33

publication ID	https://doi.org/ 10.1649/0010-065X-65.mo4.1
publication LSID	lsid:zoobank.org:pub:0818A3A2-AB42-43D8-8F76-4F65F367C584
persistent identifier	https://treatment.plazi.org/id/A9C6354B-9789-4ABA-A113-DC29703C2CB3
taxon LSID	lsid:zoobank.org:act:A9C6354B-9789-4ABA-A113-DC29703C2CB3
treatment provided by	Carolina
scientific name	Agnosthaetus heteromastax Clarke
status	sp. nov.

Treatment

(8) Agnosthaetus heteromastax Clarke View in CoL , new species

( Figs. 58 View Figs , 71 View Figs , 109 View Figs , 112 View Figs , 192–194 View Figs , Map 2 View Map 2 )

Type Material. Holotype. ♂, with five labels: “New Zealand SI| N.E. Big S. Cape I [47°13.8′S, 167°24′E]| 121m | 18 Nov. 1968 | G. Kuschel / litter| 68/191/ FMNH-INS 0000 048 070 / Duplicate| specimens| in alcohol/ HOLOTYPE Agnosthaetus heteromastax Clarke , ♂, design. D. Clarke 2011”, in NZAC GoogleMaps . Paratypes. 29 specimens (11♂, 18♀). NEW ZEALAND: South Island: SI: Doughboy Bay , 47°1′S, 167°41′E, 29.iv.2002 GoogleMaps , RL 696, leaf litter, R. Leschen, 2♂, 1♀ 1♀ (in NZAC); Stewart Island: SI: Big South Cape I. (NE) [variant name= Taukihepa], 47°13.8′S, 167°24′E [coord.= Big South Cape I.], 7.xi.1968 GoogleMaps , J. McBurney, 1♂, FMNH-INS 48074 (in NZAC); 22.ii.1969 , 69/82,

litter, J.I. Townsend, 1♀, FMNH-INS 48073 (in NZAC) ; 22.ii.1969, 69/80a, litter, J. McBurney, 2♀, FMNH-INS 48472–473 (in NZAC) ; 7.xi.1968, litter sample 2, J. McBurney, 1♂, 1♀, FMNH-INS 48469–470 (in NZAC) ; 22.ii.1969, 69/83, moss, J.I. Townsend, 1♀ 1♂, 2♀, FMNH-INS 48466– 468 (in NZAC) ; Big South Cape I. (NE), 121 m, 47°13.8′S, 167°24′E, 18.xi.1968, 68/191, litter, G. Kuschel, 2♀, FMNH-INS 48071–072 (in NZAC) GoogleMaps ; Big South Cape I. (NE), 91 m (as 300 ft), 47°13.8′S, 167°24′E, 18.xi.1968, 68/192, litter, G. Kuschel, 1♀, FMNH-INS 48474 (in NZAC) GoogleMaps ; Pegasus Crk. , 47°8.706′S, 167°42.156′E, 24.ii.1968, 68/68, litter, G. Kuschel, 1♂, 3♀, FMNH-INS 48075, 076– 078 (in NZAC) GoogleMaps ; Rakeahua Valley , 46°59.322′S, 167°50.37′E [coord.=Rakeahua River], ii.1968, 68/58, litter, G. Kuschel, 1♀ 1♂, 1♀, FMNH-INS 66845, 846 (in NZAC) GoogleMaps ; Twilight Bay , Port Pegasus, 47°12′S, 167°40.998′E, 22.ii.1968, 68/70, litter, G. Kuschel, 1♂ (in NZAC) GoogleMaps ; 22.ii.1968, 68/71[?], moss, G. Kuschel, 1♂ 1♀, FMNH-INS 66847 (in NZAC) ; 22.ii.1968, 68/62, moss, G. Kuschel, 1♂ 1♂, FMNH-INS 66848 (in NZAC) .

Diagnosis. Agnosthaetus heteromastax can be distinguished from all other species of Agnosthaetus by the combination of the smooth mentum (as in Fig. 67 View Figs ), distinctly chromosome-shaped medial pronotal sulci that are obliquely deflected anteriorly and continuous with the anterior seta ( Fig. 71 View Figs , ms, setal puncture absent), and only a single lateral elytral ridge ( Fig. 24 View Figs , ek). Additionally, the combination of the basally broader (rather than waisted) apical part of the median lobe ( Figs. 109 View Figs , 112 View Figs ) and the elongate apical part of the paramere will distinguish the aedeagus from that of A. falx (cf. Figs. 107, 109 View Figs ).

Description. Color: More or less uniformly reddish brown. Head: ( Fig. 58 View Figs ). Frontal ridge present (cf. Fig. 12 View Figs , fr). Dorsum moderately densely punctate; with punctures distributed anteriorly, laterally, and posteriorly on disc, middle part impunctate. Punctures deep, but indistinctly defined; diameter greater than diameter of eye facet; interpuncture distance mostly less than half puncture diameter. Dorsal microsculpture absent, or faintly reticulate only anterior to dorsal tentorial sulci. Dorsal tentorial sulcus (cf. Figs. 10–11 View Figs , dt) distinctly slit-like; width subequal to or less than puncture diameter ( Fig. 58 View Figs , dt). Sublongitudinal ridge (cf. Fig. 10 View Figs , sr) indistinct; confused by dorsolateral secondary carinae or punctures; crest at antennal tubercle with distinct microsculpture. Area above and behind antenno-ocular carina ( Figs. 10–11 View Figs , arrow) with several secondary carinae formed by subconfluent to confluent punctures. Antenno-ocular carina (cf. Fig. 10 View Figs , ao) indistinct; confused by secondary carinae and sculpture; joining eye at or in front of middle. Temple ( Fig. 11 View Figs , tm) short, less than 50% EYL, or long, greater than 50% EYL. Subocular surface more or less evenly microsculptured (cf. Fig. 65 View Figs ). Labrum not distinctly sexually dimorphic ( Fig. 106 View Figs ). Apical labral margin in males moderately broadly and shallowly emarginate medially, evenly dentate, all teeth normal, projecting more or less anteriorly. Apical labral margin in females slightly concave medially; with all teeth subequal in length. Adoral labral surface in males smooth, without subapical transverse ridge. Mandible sexually dimorphic; males with single, dorsally directed tooth, without preapical spur (cf. Fig. 189 View Figs ) or with variably developed spur ( Figs. 192–194 View Figs , arrows); females with single, mesially projecting tooth, without spur. Mentum smooth, unmodified. Prothorax: Pronotum without microsculpture. Medial pronotal sulci (cf. Fig. 23 View Figs ) distinctly chromosome-shaped, abruptly deflected obliquely in apical third; anteriorly separate from, and deflected obliquely to anterior punctures ( Fig. 71 View Figs ). Distance between medial sulci in front of middle about half that at base. Pronotal basolateral carina absent (cf. Figs. 23 View Figs , 69 View Figs , 77 View Figs ; note, its apparent presence in Fig. 71 View Figs , cf. Fig. 72 View Figs , bp, is an SEM artifact). Pronotal macrosetal punctures absent (cf. Fig. 77 View Figs ). Medial pronotal seta adjacent to lateral sulcus ( Fig. 71 View Figs ). Pronotal hypomeron ( Fig. 24 View Figs , hy) shiny, without microsculpture. Prosternum without microsculpture, or with faintly reticulate microsculpture. Pterothorax: Elytron ( Fig. 23 View Figs , e) without microsculpture; with 2 macrosetae, not set in punctures; laterally with single ridge (cf. Fig. 24 View Figs , ek). Mesothoracic epimeral region ( Fig. 24 View Figs , mer) shiny, without microsculpture. Metathoracic pleural region ( Fig. 24 View Figs , m) shiny, without microsculpture. Metathoracic pleural ridge present, but with longitudinal portion variously effaced; metathoracic pleural groove ( Fig. 24 View Figs , gr) complete, continuing to or near to pleurocoxal articulation. Abdomen: Abdominal vestiture long, dorsally more or less evenly projecting posteriorly but with middle setae directed posteromedially. Aedeagus ( Fig. 109 View Figs ): “ Type A” (see description on p. 8). Apical part of median lobe wider at base, gradually produced into acute, sharp point. Both apicolateral and apicomedial setae short ( Fig. 112 View Figs ). Paramere exceeding apex of median lobe; lamellate, in dorsal view distinctly broadened apically; with apical part twisted, parallel to median lobe; in dorsal view with outer side gently convex; with 4 large, mesially directed setae arranged in close line at apex.

Etymology. The specific epithet heteromastax is a noun in apposition from the Greek heteros, differing or varying, and mastax, jaws, and refers to the intraspecifically variable mandibles of this species.

Distribution. ( Map 2 View Map 2 ). Stewart Island: SI.

Biology and Ecology. Habitat: presumably forest. Specimens have been taken from leaf litter and moss. Phenology: February, September. Elevation: 91– 121 m.

Remarks. Males of this southernmost species of Agnosthaetus exhibit remarkably robust mandibles, which take three geographically structured forms ( Figs. 192–194 View Figs ). Northwestern specimens (Doughboy Bay, Rakeahua Valley) have robust mandibles with a distinct but only minutely developed preapical spur ( Fig. 192 View Figs , arrow); northeasternmost specimens (Pegasus Crk; Twilight Bay) exhibit remarkably robust mandibles in comparison to A. falx and A. stenomastax , which have a large preapical tooth much closer to the apex of the mandible than is typical for other species in the genus ( Fig. 194 View Figs , arrow); southernmost specimens (Big South Cape Island) have robust mandibles lacking any preapical spur ( Fig. 193 View Figs ). These three disparate populations exhibit identical male genitalia (including internal sac structures), and thus must reflect local populationlevel divergence. This form of mandibular polymorphism, in which there are distinct forms with apparently no intermediates, is unusual for Euaesthetinae , and the overall robust appearance of the male mandibles of this species is diagnostic.