Agnosthaetus falx 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 : 29-30

(6) Agnosthaetus falx Clarke , new species

( Figs. 104, 107, 110, 190, Map 2)

Type Material. Holotype. ♂, with five labels: “NEW ZEALAND SI| Golden Bay | Stewart Island | 11-Jan-96 [5 m, 46°54.3′S, 168°7.3′E]/ In decayed| wood/ JT Nunn| collection/ FMNH-INS 0000 019 712 / HOLOTYPE Agnosthaetus falx Clarke , ♂, design. D. Clarke 2011”, in JTNC. On card . Paratypes. 10 specimens (6♂, 4♀). NEW ZEALAND: Stewart Island: SI: Christmas Valley / Village , 46°44.79′S, 167°58.734′E [coord.= Christmas Village Hut], 28.i.1962, 62/5, litter, J.I. Townsend , 1♂, FMNH-INS 48471 (in NZAC) ; Garden Mound , 40 m, 46°52.002′S, 168°7.002′E, mixed podocarp/broadleaf & tree fern forest, 10.ii.1991, LCNZ 91/1, litter, R.M. Emberson , 1♀, FMNH-INS 19069 (in LUNZ) ; Garden Mound Trk. , 46°52.182′S, 168°7.068′E [coord.= Garden Mound], 21.i.2007, RL 1175, moss sample, R. Leschen , 1♂, 1♀ (in JTNC) ; Golden Bay , 5 m, 46°54.3′S, 168°7.3′E, 11.i.1996, in decayed wood, J.T. Nunn , 1♂, FMNH-INS 19710 (in JTNC) ; Golden Bay , 5 m, 46°54.3′S, 168°7.3′E, forest, 9.i.1996, in forest litter, J.T. Nunn , 1♂, FMNH- INS 19711 (in JTNC) ; Pryse Peak Trk. , 46°56.49′S, 168°0.246′E [coord.= Pryce Peak], 24.i.2007, RL 1206, moss & liverwort sample, R. Leschen , 1♂, FMNH-INS 48251 (in JTNC) ; Ulva I., 46°56′S, 168°8′E, 24.iv.2002, RL 682, rotten leaf litter, R. Leschen, 1♀ (in NZAC) ; 24.iv.2002, RL 681, rotten twigs litter, R. Leschen, 1♂ (in NZAC) ; Ulva Island , 46°56.088′S, 168°7.896′E, mixed podocarpcoastal forest, xi-xii.2003, mixed podocarp-coastal litter, P. Michel , 1♀, FMNH-INS 19379 (in JTNC) .

Diagnosis. Agnosthaetus falx can be distinguished externally from all other species of Agnosthaetus except A. stenomastax by the combination of the smooth mentum (as in Fig. 67), antenno-ocular carina of head meeting eye in front of middle of eye (as in Figs. 58, 61–62, ao), both the antenno-ocular carina and sublongitudinal ridge of head obscured by secondary lateral carinae (as in Fig. 58), the slightly impressed medial pronotal sulcus, and the pronotal basolateral carina (as in Fig. 72, bp). Additionally, the combination of the slightly waisted apical part of the median lobe ( Fig. 107, arrow) and the apical part of the paramere subparallel with the median lobe apex will distinguish the aedeagus from that of both A. stenomastax and A. heteromastax (cf. Figs. 107–109).

Description. Color: More or less uniformly reddish brown. Head: Frontal ridge present (cf. Fig. 12, 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. Dorsal tentorial sulcus (cf. Figs. 10–11, dt) distinctly slit-like; width subequal to or less than puncture diameter. Sublongitudinal ridge (cf. Fig. 10, 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, 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. Temple ( Fig. 11, tm) short, less than 50% EYL. Subocular surface more or less evenly microsculptured (cf. Fig. 65). Labrum not distinctly sexually dimorphic ( Fig. 104). 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, with distinct preapical spur ( Fig. 190, arrow); females with single, mesially projecting tooth, without spur. Mentum smooth, unmodified. Prothorax: Pronotum without microsculpture. Medial pronotal sulci (cf. Fig. 23) more or less straight or slightly curving (cf. Figs. 75–76); anteriorly separate from and terminating posterior to anterior punctures. Distance between medial sulci slightly greater posteriorly. Pronotal basolateral carina present, distinct (cf. Fig. 76, bp). Pronotal macrosetal punctures absent (cf. Fig. 77). Medial pronotal seta adjacent to lateral sulcus (cf. Fig. 72). Pronotal hypomeron ( Fig. 24, hy) shiny, without microsculpture. Prosternum without microsculpture, or with faintly reticulate microsculpture. Pterothorax: Elytron ( Fig. 23, e) without microsculpture; with 2 macrosetae, not set in punctures; laterally with single ridge (cf. Fig. 24, ek). Mesothoracic epimeral region ( Fig. 24, mer) shiny, without microsculpture. Metathoracic pleural region ( Fig. 24, m) shiny, without microsculpture. Metathoracic pleural ridge present, but with longitudinal portion variously effaced; metathoracic pleural groove ( Fig. 24, 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. Abdominal sternite IV of male with surface nearly glabrous apicomedially, apex slightly convex apicomedially; V with surface glabrous and slightly impressed apicomedially, apparently without modified setae, and apex distinctly convex; VI with surface glabrous apicomedially, without modified setae. Aedeagus ( Fig. 107): “ Type A” (see description on p. 8). Apical part of median lobe slightly narrower at base, forming weak apicolateral lobes, produced into narrowly acute, sharp point ( Fig. 107, arrow). Both apicolateral and apicomedial setae short ( Fig. 110). Paramere extending to about level of median lobe apex; in lateral view produced apically into lobe; 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 falx is a noun in apposition, from the Latin falx , sickle or scythe, in reference to the scythe-like appearance of the parameres.

Distribution. ( Map 2). South Island: SI.

Biology and Ecology. Habitat: mixed podocarpbroadleaf forest. Specimens have been taken from bryophytes and forest leaf litter. Phenology: February, September. Elevation: 5– 40 m.

Remarks. This is one of three morphologically close species endemic to Stewart Island (including the nearby Codfish Island). The presence of the basolateral carina (as in Fig 72) and straight pronotal sulci easily distinguish A. falx from A. heteromastax , but not from A. stenomastax . From the latter species, A. falx can be most easily distinguished by the slightly waisted median lobe ( Figs. 107, 110, cf. 109, 112) and broader parameral apex (cf. Figs. 107, 109).