Agnosthaetus enigmus 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 : 69-70

(33) Agnosthaetus enigmus Clarke , new species

( Figs. 182, 186, Map 7)

Type Material. Holotype. ♂, with nine labels: “[Thomas Broun’ s handwriting on this and following three labels] 3989/ Staircase | Canterbury [43°13′28″S, 171°55′59″E]/ Dimerus | vicinus.| Broun/ T. Hall. | 15.3–1914/ A.E. Brookes | Collection/ T. Broun | Collection/ FMNH-INS 0000 048 260 / Agnosthaetus | spec. nov. 8| det. Puthz 200 4 / HOLOTYPE Agnosthaetus enigmus Clarke , ♂, design. D. Clarke 2011”, in NZAC. Specimen and terminal abdominal segments on card; aedeagus in glycerine vial . Paratype. 1 specimen (1♀), same data as holotype, FMNH-INS 42817 (in BMNH) .

Diagnosis. In addition to the characters given in the nunni species-group diagnosis, A. enigmus may be distinguished from all other known Agnosthaetus species by the combination of the coarsely punctate head, temple ( Fig. 11, tm) <50% EYL, and only faint elytral and hypomeral ( Fig. 24, hy) microsculpture. Males may be easily distinguished from all other species by the distinct but minute triangular medial tooth at the apex of the labrum (similar to that of A. carnelius : Fig. 178, but smaller). The aedeagus may be distinguished from others in this species-group by the nearly straight-sided parameres in dorsal view, and straight apices in lateral view ( Fig. 182, cf. Figs. 180–181, arrow).

Description. Color: More or less uniformly yellowish brown. Head: Frontal ridge absent. Dorsum sparsely punctate; with punctures distributed over more or less entire surface except for small posterior impunctate region. Punctures shallow, rather indistinct; diameter subequal to or slightly greater than diameter of eye facet; interpuncture distance approximately 0.5–1.0X puncture diameter. Dorsal microsculpture present on entire or most of surface; distinctly reticulate, fainter posteriorly. Dorsal tentorial sulcus (cf. Figs. 10–11, dt) distinctly slitlike; width subequal to or less than puncture diameter. Sublongitudinal ridge (cf. Fig. 10, sr) distinct; not confused by smaller carinae or punctures (cf. Fig. 10, sr); crest at antennal tubercle with distinct microsculpture. Area above and behind antennoocular carina ( Figs. 10–11, arrow) more or less smooth, without subsidiary carinae. Antenno-ocular carina joining eye at or behind middle (cf. Fig. 10, ao). Temple ( Fig. 11, tm) short, less than 50% EYL. Subocular surface more or less evenly microsculptured (cf. Fig. 65). Labrum distinctly sexually dimorphic. Apical labral margin in males strongly emarginate medially, evenly dentate, with 16 teeth (n =1), with medial, dorsally projecting tooth, twice width of paramedial teeth. Apical labral margin in females broadly convex, not emarginate medially; with 19 teeth (n =1), all teeth subequal in length. Mandible sexually dimorphic; males with single, dorsally directed tooth, with weakly developed preapical spur (cf. Fig. 190, arrow); females with single, mesially projecting tooth, without spur. Prothorax: Pronotum with faintly reticulate microsculpture. Medial pronotal sulci anteriorly separate from and terminating posterior to anterior punctures. Distance between medial sulci very slightly greater posteriorly. Pronotal basolateral carina present, but only weakly developed (cf. Fig. 76, bp). Anterior pronotal puncture (cf. Fig. 70, ap) distinct; medial puncture (cf. Fig. 70, mu) distinct; basal puncture ( Fig. 70, bu) indistinct. Medial pronotal seta subequidistant from medial and lateral sulci (cf. Fig. 73, mu). Pronotal hypomeron ( Fig. 24, hy) with distinct reticulate microsculpture. Prosternum with distinctly reticulate microsculpture. Pterothorax: Elytron ( Fig. 23, e) with faint but distinct microsculpture; with 2 macrosetae, set in distinct punctures; laterally with single ridge (cf. Fig. 84, ek). Mesothoracic epimeral region ( Fig. 24, mer) with at most faint microsculpture. Metathoracic pleural region ( Fig. 24, m) with distinct reticulate microsculpture. Metathoracic pleural ridge fully developed; metathoracic pleural groove ( Fig. 24, gr) 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 VII of male with surface glabrous and slightly impressed apicomedially. Aedeagus ( Fig. 182): “ Type B” (see description on p. 8). Apical part of median lobe slightly narrower basally, not forming distinct lateral lobes; produced into elongate, acute, and sharp point. Apicolateral setae small; apicomedial setae up to 10X longer than apicolateral setae ( Fig. 186). Paramere not exceeding apex of median lobe; in lateral view produced apically into lobe; with apical part perpendicular to median lobe; in dorsal view with outer side more or less straight; with 4 setae on ventral edge of apex.

Etymology. The specific epithet enigmus is a noun in apposition, derived from the Greek aenigma, a riddle or mystery, for its uncertain locality and initially unclear identity.

Distribution. ( Map 7). South Island: MC.