Osoriellus sexdentatus n. sp.

(Figs 9 A-D, 11E)

Type material: Holotype, male: French Guiana: Wanaboo (near Nason) Marowijne River, 40 m elevation (54°26.36'W, 4°43.35'N), ex flight intercept trap, 31.5.- 5.6.1999, leg. Z.H. Falin & B. DeDijn, SUR1F99 032 (KNHM).

Diagnosis: The species resembles O. ocularis and O. oculatus by its large prominent eyes. The eyes are similarly large as in O. oculatus and, therefore, slightly smaller than in O. ocularis . The front edge of the clypeus is similar as in O. ocularis, but with only four teeth between the larger outer teeth and not with six teeth as in O. ocularis .

Description: Length: 4.0 mm. Colouration: Black; elytra and abdomen brown; legs and antennae light brown.

Head: 0.63 mm long, 0.79 mm wide; eyes prominent; longer than temples; sides of fore-head evenly convergent; angles of clypeus produced to long teeth and four smaller teeth on anterior edge; punctation dense and coarse and with impunctate midline on vertex; clypeus with isodiametric microsculpture; surface slightly shiny; vertex without microsculpture; surface polished and shiny; several setiferous punctures at upper margin of eyes; two setiferous punctures on vertex and several setiferous punctures on clypeus.

Antennae slightly longer than head; with second antennomere oblong and thicker than conical third antennomere; following 3 antennomeres as wide as third, but quadrate; antennomeres 7 to 11 distinctly thicker than preceding antennomeres; more or less quadrate.

Pronotum: 0.76 mm, 0.81 mm wide; widest at anterior angles; slightly narrowed in anterior two-third; in posterior third abruptly more strongly narrowed; setiferous punctation large and in irregular rows; within row interstices between punctures only half as wide as diameter of punctures; between rows interstices as wide as diameter of punctures; without microsculpture, but with sparse micro-punctation; surface polished and shiny.

Key to the species

1. Eyes large and distinctly prominent, temples shorter than eyes. .................................................................... 3

- Eyes not or slightly prominent, as long as temples. ................................................................................... 2

2. Front edge of clypeus with 8 teeth between tooth-like angles. .......................................... O. hanagarthi n. sp.

- Front angles of clypeus produced to long bidentate teeth. ............................................ O. denticornis n. sp.

3. Between 4.2 and 4.7 mm long, anterior edge of clypeus with 3 short lateral teeth and even slightly prominent middle. .............................. O. oculatus (SHARP, 1876)

- Between 3.7 and 4.0 mm long, anterior edge of clypeus with more than 3 teeth. ............................................. 4

4. Clypeus with 6 short teeth between long teeth at angles. ............................................... O. ocularis n. sp.

- Clypeus with 4 short teeth between long teeth at angles. ........................................ O. sexdentatus n. sp.

Elytra: 0.96 mm long, 0.87 mm wide; with coriaceous ground-sculpture and weak setiferous punctation; interstices between punctures at least as wide as diameter of punctures.

Abdomen densely punctate; with large setiferous punctures; yellow setae pointing posteriad; without impunctate midline.

Protibia: 0.50 mm long, 0.13 mm wide; with 8 spines at outer edge; apical spines inserted on moderately long digits; WLR: 1.0; in posterior aspect, comb at inner emargination visible throughout its total length; posterior face densely covered by long yellow setae.

Aedeagus with triangular apical lobe and several sensillae at inner edge.

Etymology: The specific name refers to the 6 teeth at the anterior edge of the clypeus.