Diochus amazonensis, Irmler, 2017

Irmler, Ulrich, 2017, A review of the Neotropical genus Diochus ERICHSON, 1840 (Coleoptera: Staphylinidae: Staphylininae), Beiträge Zur Entomologie = Contributions to Entomology 67 (1), pp. 1-62 : 9

Diochus amazonensis spec. nov.

urn:lsid:zoobank.org:act:D2230764-A93A-46CF-B5F0-F4E6963E26DF

Figs 16A–C , 42C

Type material: male, Holotype: Brazil: Amazonas , Manaus, Ilha Marchanteria (59°58'W, 3°15'S), floating meadow, 4.11.1981, leg. J. Adis, #BE50B ( INPA).

Diagnosis: Within the D. inornatus-group, D. amazonensis resembles D. antennalis by the light yellow colouration. It is slightly larger than D. antennalis , the eyes are slightly longer, the head is less divergent to the posterior margin, and the antennae are distinctly longer. Moreover, the paramere is more slender than that of. D. antennalis and the apex is symmetrically widened and not asymmetric like in D. antennalis . Unfortunately, only the male holotype is known.

Description: Length: 3.5 mm. Colouration: unicoloured yellow.

Head: 0.51 mm long, 0.43 mm wide; eyes large; slightly prominent; temples twice as long as eyes; EL: HL = 0.27; sides of temples slightly divergent to posterior angles; PW: EW = 1.18; posterior angles obtusely angulate; posterior margin nearly straight; setiferous punctation sparse and deep; row of six to seven punctures adjacent to wide impunctate midline; postocular area more densely punctate; microsculpture extremely weak; transversely reticulate; surface nearly polished.

Antennae as long as head and pronotum combined; first antennomere thicker than following antennomeres; one third longer than second and third antennomere; conical second antennomere thicker than third antennomere; twice as long as its apical width; conical third antennomere nearly three times longer than its apical width; length of following antennomeres decreasing; fourth antennomere twice as long as wide; seventh antennomere only slightly longer than wide; following antennomeres approximately quadrate; all antennomeres pubescent; basal antennomeres with few long setae.

Pronotum: 0.58 mm long, 0.45 mm wide; sides nearly parallel; anterior angles widely rounded; anterior margin nearly semi-circular; posterior angles obtuse; lateral margin fine; in dorsal aspect, visible in posterior two third; setiferous punctation sparse and moderately deep; adjacent to wide impunctate midline with row of three punctures; interstice between first pair of punctures one third wider than between posterior two pairs; laterad with irregular number of five to six punctures; along lateral margin with several setiferous punctures; without microsculpture; surface polished.

Elytra 0.63 mm long, 0.57 mm wide; sides slightly divergent to posterior margin; posterior margin with slightly triangular emargination; shoulders obtusely angulate; setiferous punctation in irregular rows of five to six punctures; weak ground sculpture coriaceous; surface shiny.

Abdomen densely pubescent.

Aedeagus broad and stout; seminal vesical of endophallus slightly longer than half of central lobe’s length; basal inner duct looped, ending in weakly sclerotised forceps; apical inner duct filamentous; forming one long coil; paramere slender; not exceeding central lobe; slender shaft widened shortly in front of apex to approximately circular expansion; at apex with four long setae; at outer side with four sensillae.

Etymology: The species name refers to he Brazilian state

Amazonas, where it was collected.

Figures

Figs 42: Fore-bodies of Diochus antennalis (A), D. tricolor (B), D. amazonensis (C), D. hermani (D), D. plaumanni (E), D. hibbsi (F), D. newtoni (G), D. novus (H); scale bar: 0.5 mm.

Figs 14–17: Diochus inornatus-group: of D. schuelkei (14), D. hermani (15), D. amazonenis (16), D. hibbsi (17); aedeagus (A),