Agnosthaetus chiasma 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 : 21-23

(2) Agnosthaetus chiasma Clarke , new species ( Figs. 2 , 13 , 65 , 69 , 85 , 90 , 95 , 99 , 188 , Map 1 )

Type Material. Holotype. ♂, with four labels: “New Zealand| [WD] Haast River 100 m | Sunny Flat [43°58′S 169°24′E]| 25.i.1978 | G.Kuschel/ sifted litter| 78/54/ FMNH-INS 0000 048 037/ HOLOTYPE Agnosthaetus chiasma Clarke , ♂, design. D. Clarke 2011”, in NZAC. Paratypes. 117 specimens (39♂, 35♀, 43 unsexed). NEW ZEALAND: South Island: OL: Haast Pass, Found Crk. Culvert, 44°9′S, 168°19′E, 6.iii.2003, RL 785, sifting leaf litter & rotting logs, R. Leschen & C. McGuiness, 2♂ (in NZAC); Makarora, 44°14′S, 169°14′E, 15.iii.1966, 2 sex unknown, FMNH-INS 19369 (in JTNC); 3.ii.1984, 84/19, sifted litter, J.C. Watt, 2♀, FMNH-INS 48038–039 (in NZAC); Makarora, 500 m, 44°14′S, 169°14′E, 23–25.i.1978, ber. litter und. carrion, S. & J. Peck, 1♂, FMNH-INS 42806 (in MCZ); Makarora, 300 m, 44°14.27′S, 169°13.98′E, Nothofagus forest, 3.i.1984, leaf litter, P.M. Hammond, 2♂, FMNH-INS 19046, 048 (in BMNH); Makarora Bush, 330 m, 44°13.774′S, 169°14.021′E, 7–9. xi.1997, J.T. Nunn, 1 sex unknown, FMNH-INS 19719 (in JTNC); Makarora Valley, 44°7.83′S, 169°21′E, 12.xii.1977, R.R. Forster, 5♂, 4♀, FMNH-INS 19761–769 (in OMNZ); Makarora Valley, Cameron Flat, 380 m, 44°9′29″S, 169°17′52″E, 22.i.1996, J.T. Nunn, 1♀, FMNH-INS 19749 (in JTNC); Makarora Valley, Davis Flat, 470 m, 44°7.6′S, 169°20.34′E, sifted moss sample, J.T. Nunn, 1♂, 1♀ (in JTNC); Mt. Aspiring N.P., Haast Pass (SE of), 600 m, ANMT 739, 44°7′S, 169°21′E, Nothofagus menziesii forest, 14.i.1985, FMHD#85- 472, litter, forest, Berl., A. Newton & M. Thayer, 35 sex unknown, 2 larvae (in ethanol); 1♂, 1♀, FMNH- INS 48034–035 (in FMNH); 17.i.1985, Nothofagus menziesii logs, pyr.-fog., A. Newton & M. Thayer, 1♂, FMNH-INS 48036 (in FMNH); Mt. Aspiring N.P., Makarora (12.5 km NNE of), 370 m, ANMT 740, 44°9′S, 169°19′E, Nothofagus menziesii - hardwood-podocarp forest, 14.i.1985, FMHD#85- 473, litter, forest, Berl., A. Newton & M. Thayer, 7♂, 4♀ 1♂, 1 larva, FMNH-INS 48029, 1♀, FMNH-INS 48030 (in FMNH); Mt. Aspiring N.P., Makarora (5.5 km NNE of), 330 m, ANMT 741, 44°12′S, 169°16′E, Nothofagus menziesii forest, 14.i.1985, FMHD#85-474, litter, forest, Berl., A. Newton & M. Thayer, 2♂, 3♀ 1♀, FMNH-INS 48031 (in FMNH); 14.i.1985, on & under gilled mushrooms, A. Newton & M. Thayer, 1♀, FMNH- INS 48033 (in FMNH); 11–17.i.1985, window trap, A. Newton & M. Thayer, 1♀, FMNH-INS 48032 (in FMNH); Paradise N., Lake Wakatipu, 44°43.62′S, 168°21.42′E [coord. = Paradise], 2.ii.1984, leaf litter, P.M. Hammond, 3♂, 2♀, FMNH-INS 19053–057 (in BMNH); WD: Fantail Falls, Haast Pass (4 km N), 450 m, 44°4.81′S, 169°23.22′E, Nothofagus forest, 4.i.1984, Nothofagus forest litter, P.M. Hammond, 1♂, 2♀, FMNH-INS 19050–052 (in BMNH); 4.i.1984, river bank debris, P.M. Hammond, 1♀, FMNH-INS 19049 (in BMNH); Fox Glacier (2 km SE), 225 m, 43°29′S, 170°1′E, Nothofagus / Podocarpus forest, 17.i.1998, NZEA 1L C98 072, berl., leaf litter, R. Leschen & C. Carlton, 1♂, KUNHM-ENT SM0365213, 1♀, KUNHM-ENT SM0364430 (in KSEM); Haast (56.5 km SE), Haast River Walk, Fantail Falls Trk., 475 m, 44°5′S, 169°23′E, 17.i.1998, NZEA 1L C98 073, berl., Nothofagus menziesii leaf litter, R. Leschen & C. Carlton, 1♂, 1♀, KUNHM-ENT SM0364652–653 (in KSEM); Mahitahi (6 km SW), 43°38.98′S, 169°36′E, swamp forest, 5.i.1984, leaf litter, P.M. Hammond, 1♂, 1♀, FMNH-INS 19045, 047 (in BMNH); Mt. Aspiring N.P., Douglas Creek at Hwy. 6, 65 m, ANMT 738, 43°57′S, 169°20′E, Nothofagus menziesii -hardwood-podocarp, 15.i.1985, FMHD#85-471, litter, forest, Berl., A. Newton & M. Thayer, 1♀, FMNH-INS 48046 (in FMNH); WD / OL: Haast Pass, 44°6′S, 169°21′E, 10.iv.1979, R.R. Forster, 8♂, 2♀, FMNH-INS 19751–760 (in OMNZ); Haast Pass, summit, 560 m, 44°7′S, 169°21′E, 22.i.1978, 78/48, litter, ground plants and decayed wood, G. Kuschel, 1♀, FMNH-INS 42801, 1 sex unknown, 1♂, 2♀, FMNH-INS 42802–805 (in NZAC); 1♀, FMNH- INS 42800 (in Puthz).

Diagnosis. Agnosthaetus chiasma may be distinguished from all other Agnosthaetus species with a basal mental tooth ( Fig. 65 , arrow) by the combination of the faint microsculpture of the head, the distinctive chromosome-shaped medial pronotal sulci with the apices deflected obliquely, but continuous with the anterior punctures ( Fig. 69 , ms), and the absence of the metathoracic pleural ridge ( Fig. 85 ; cf. Fig. 24 , mp).

Description. Color: More or less uniformly reddish brown ( Fig. 2 ). Head: Frontal ridge present (cf. Fig. 12 , fr). Dorsum sparsely punctate; with punctures distributed anteriorly, laterally, and posteriorly on disc, middle part impunctate. Punctures deep, but indistinctly defined; diameter subequal to diameter of eye facet; interpuncture distance mostly less than half puncture diameter ( Fig. 13 ). Dorsal microsculpture present only anterior to dorsal tentorial sulci; very faintly reticulate. Dorsal tentorial sulcus (cf. Figs. 10–11 , dt) distinctly slitlike; straight, distinctly impressed between sublongitudinal ridge and medial part of vertex. Sublongitudinal ridge (cf. Fig. 10 , sr) indistinct; confused by dorsolateral secondary carinae or punctures ( Fig. 13 ); crest at antennal tubercle with distinct microsculpture. Area above and behind antenno-ocular carina ( Figs. 10–11 , arrow) with several secondary carinae formed by subconfluent to confluent punctures. Antenno-ocular carina (cf. Fig. 10 , ao) indistinct; confused by secondary carinae; joining eye at or in front of middle ( Fig. 13 ). Eye distinctly bulged anteriorly. Temple ( Fig. 11 , tm) very short, much less than 50% EYL ( Fig. 13 ). Suboccular surface more or less evenly microsculptured ( Fig. 13 ). Labrum not distinctly sexually dimorphic ( Fig. 90 ). Apical labral margin in males shallowly emarginate medially, evenly dentate, with 17–20 teeth (n =5), and all teeth normal, projecting more or less anteriorly. Apical labral margin in females very slightly concave medially; with 16–20 teeth (n =6), all teeth subequal in length. Medial oblique labral setae (cf. Fig. 20 ) absent. Adoral labral surface in males smooth, without subapical transverse ridge ( Fig. 65 ). Mandible sexually dimorphic; males with single dorsally directed tooth, with distinct preapical spur (cf. Fig. 190 , arrow); females with single mesially projecting tooth, without spur. Mentum with distinct basomedian tooth ( Fig. 65 , arrow). Prothorax: Pronotum without microsculpture. Medial pronotal sulci (cf. Fig. 23 ) distinctly chromosome-shaped, abruptly deflected obliquely in apical third; anteriorly continuous with anterior punctures ( Fig. 69 , ms). Distance between medial sulci in front of middle about half that at base. Pronotal basolateral carina absent (cf. Figs. 23 , 69 , 77 ). Anterior pronotal puncture (cf. Fig. 70 , ap) absent; medial puncture (cf. Fig. 70 , mu) indistinct; basal puncture ( Fig. 70 , bu) indistinct. Medial pronotal seta adjacent to lateral sulcus ( Fig. 69 ). Pronotal hypomeron ( Fig. 24 , hy) shiny, without microsculpture. Prosternum without microsculpture, or with distinctly reticulate microsculpture. Pterothorax: Elytron ( Fig. 23 , e) without microsculpture; with small punctiform non-setiferous impressions; with one macroseta, not set in punctures; laterally with single ridge ( Fig. 85 , ek). Elytral epipleuron ( Fig. 24 , ef) very narrow, more or less even width for most of length. Mesothoracic epimeral region ( Fig. 24 , mer) shiny, without microsculpture. Metathoracic pleural region ( Fig. 24 , m) shiny, without microsculpture. Metathoracic pleural ridge absent ( Fig. 85 ), but oblique portion sometimes indistinct; metathoracic pleural groove ( Fig. 24 , gr) complete, continuing to or near to pleurocoxal articulation, or incomplete posteriorly, forming elongate oval punctiform impression. Abdomen: Abdominal vestiture long, dorsally more or less evenly projecting posteriorly but with middle setae directed posteromedially. Abdominal sternite III of male glabrous and very slightly impressed apicomedially; IV with surface glabrous and very slightly impressed apicomedially; V with surface glabrous and impressed apicomedially, flanked by diffuse coarser acuminate setae, apex distinctly convex; VI with dense patch of coarse setae apicomedially, apex slightly convex. Aedeagus ( Fig. 95 ): “ Type A” (see description on p. 8). Apical part of median lobe with rounded lateral lobes, gradually produced concavely to broad point. Both apicolateral and apicomedial setae short ( Fig. 99 ). Paramere exceeding apex of median lobe; lamellate, in lateral view distinctly broad along most of length; with apical part twisted, parallel to median lobe; in dorsal view with outer side sinuously curving; with 2 setae at apex, 1 on ventral edge, and 1 on ventral face.

Etymology. The name chiasma is a noun in apposition, from the Greek chiasma, meaning two lines crossed like the Greek letter chi, referring to the distinctly shaped pronotal sulci that somewhat resemble the shape of chromosomes during cellular metaphase.

Distribution. ( Map 1 ). South Island: OL; WD.

Biology and Ecology. Habitat: swamp, podocarp, and Nothofagus forest. Specimens have been taken by sifting leaf and log litter, from moss, on gilled mushrooms, in a window trap, from river bank debris, from leaf litter under carrion, and by pyrethrum-fogging of old logs.Phenology:November- January. Elevation: 65– 600 m.

Remarks. This species is most similar to A. brounides , but since that species and the related species A. bisulciceps each possess excellent combinations of diagnostic characters, A. chiasma might more likely be confused with A. rodmani . In addition to the characters in the diagnosis, it can be distinguished from that species by the faint, nearly obsolete microsculpture of the head, lack of microsculpture on the sides of the thorax, and the presence of only a single seta on each elytron. The aedeagus of this species is most similar to A. brounides , but it differs most significantly from that species in having the paramere distinctly twisted apically so that the apical part is parallel with the median lobe ( Fig. 95 ). Similar to A. brounides , the paramere has two setae at the apex, but one of the larger setae is positioned on the ventral side of the paramere ( Fig. 95 ).

Figures

Map 1. Geographic distribution of all georeferenced specimens in the Agnosthaetus brounides species-group. Triangles = A. brounides; circles = A. bisulciceps; Xs = A. rodmani; squares = A. chiasma; stars = A. cariniceps.

Figs. 1–8. Habitus photographs of Agnosthaetus spp. 1) A. brounides; 2) A. chiasma; 3) A. zonatus; 4) A. kaikoura;

Figs. 10–13. Head capsules of Agnosthaetus spp. 10) A. stilbus; 11) A. rodmani; 12) A. brouni; 13) A. chiasma. Scale bars = 100 mm.

Figs. 63–68. Heads of Agnosthaetus spp., ventral view. 63) A. brouni; 64) A. stilbus, oblique view; 65) A. chiasma;

Figs. 69–74. Pronota of Agnosthaetus spp. 69) A. chiasma; 70) A. rodmani; 71) A. heteromastax; 72) A. stenomastax;

Figs. 83–88. Pterothoraces of Agnosthaetus spp., right lateral view. 83) A. lanceolatus; 84) A. stilbus; 85) A. chiasma;

Figs. 89–93. Male (left) and female (right) labra of species in the Agnosthaetus brounides species-group, dorsal (anterior margin) view. 89) A. brounides; 90) A. chiasma; 91) A. bisulciceps; 92) A. rodmani; 93) A. cariniceps. Scale bar = 100 mm.

Figs. 94–97. Aedeagi of species in the Agnosthaetus brounides species-group, dorsal (left) and right lateral (right) views. 94) A. brounides; 95) A. chiasma; 96) A. bisulciceps; 97) A. rodmani. Scale bar = 100 mm.

Figs. 98–101. Apex of median lobe of species in the Agnosthaetus brounides species-group, ventral view.

Fig. 188. Agnosthaetus chiasma, abdominal segments III-IV. Scale bar = 100 mm.

Figs. 23–24. Agnosthaetus cariniceps, thorax. 23) Dorsal view; 24) Left lateral view. Scale bars = 100 mm.

Figs. 14–20. Agnosthaetus brounides. 14) Head capsule, dorsal view; 15) Head capsule, ventral view; 16) Mandibles, dorsal view; 17) Right antenna, dorsal view; 18) Right maxilla, ventral view; 19) Labium, ventral view; 20) Labrum, dorsal view. Notes: A. brounides lacks the mo setae; circular dotted region between the mo setae indicates position of the adoral glandular pit, which from above is frequently visible as a darker region. Scale bars = 100 mm.

Figs. 189–194. Mandibles of Agnosthaetus spp., dorsal view (189–193, left; 194, right). 189) A. newtoni; 190) A. falx; 191) A. stenomastax; 192) A. heteromastax (Rakeahua Valley); 193) A. heteromastax (Big South Cape Island); 194) A. heteromastax (Twilight Bay). Scale bar = 100 mm.

Figs. 75–78. Pronota of Agnosthaetus spp. 75) A. vicinus; 76) A. stilbus; 77) A. nitidus; 78) A. brouni. Scale bar =