Cornugon leios sp. nov.

(Figs 33–37, 55, 83, 84)

Diagnosis. Vertex with a complete median groove and with a groove delimiting posterior part of ocellar triangle (Fig. 35); scutellum with a deep and distinct median groove in anterior 2/3 (Fig. 36); propodeum with a complete median carina (Fig. 37); hind coxa conspicuously hairy on posterior surface; petiole 2X as long as wide and reticulate with small meshes; first gastral tergite shiny and large, covering 2/3 the length of gaster.

Similar to C. petiolatum and C. unicornis, but differing from the former in having a shorter petiole and from the latter in lacking a horn on the upper-median frons.

Description. FEMALE. Length 1.2–1.4 mm. Antenna dark brown except scape usually white (specimen from Altamira with basal 2/3 dark brown). Frons metallic dark purple. Vertex metallic bluish-purple or bluish-green. Mesoscutum metallic bluish-purple or bluish-green. Scutellum with anterior 2/3 metallic bluish-purple or bluishgreen, posterior 1/3 metallic dark purple. Propodeum metallic bluish-green. Coxae dark and metallic; femora, tibiae and tarsi white (specimen from Altamira with femora predominantly dark brown). Wings hyaline. Petiole metallic dark purple. Gaster with first tergite metallic bluish-purple, remaining tergites metallic purple.

Antenna as in Fig. 83. Frons smooth and shiny (Figs 33, 34); antennal scrobes uniting below frontal suture; frontal suture incomplete, terminating at the distance equal to one ocellus from each eye; tentorial pits missing (Fig. 33). Vertex smooth and shiny (Fig. 35), medially with a groove between occipital margin and anterior ocellus.

Mesonotum with a more or less round fovea medially between mesoscutum and scutellum (Fig. 36). Mesoscutum smooth and shiny (Fig. 36) except midlobe with strong pitlike reticulation along anterior margin. Scutellum with anterior 2/3 smooth and shiny except for distinct median groove (Fig. 36), posterior 1/3 with raised, strong reticulation. Dorsellum hidden under scutellum, not visible in dorsal view (Fig. 36). Propodeum with a complete, strong median carina, smooth and shiny between plicae (Fig. 37).

Petiole 2X as long as wide and reticulate with small meshes, hence dull (Fig. 37). Gaster ovate with first gastral tergite shiny and large, covering 2/3 length.

MALE. Length 1.1 mm. Colour as in female. Antenna as in Fig. 84. Structure otherwise as in female.

Type material. Holotype female (INBio) labelled “ Costa Rica, Guanacaste, Parque Nacional Diriá, Retallano, alred. Torre Control de Incendio, 600–700 m, LN 238550/358650, 16.xii.2000– 16.i.2001, I. Jiménez, #66659”. Paratypes. 3Ƥ 13 on cards. COSTA RICA. Guanacaste: with same label data as holotype (1Ƥ, BMNH); Bagaces, Parque Nacional Palo Verde, Sector Palo Verde, Extremo E. Campo Aterrizaje, 10 m, LN 388400/259050, 10.i–9.ii.2001, I. Jiménez (13, INBio); Puntarenas: San Vito, Las Cruces, Wilson Botanical Garden, 1000–1300 m, 8˚47'N 82˚58'W, 7–19.ii.2007, C. Hansson (1Ƥ, BMNH); Estacion Altamira, Sendero Los Gigantes, 9˚02'N 83˚00'W, 1460 m, 13.iii–13.iv.2001, D. Rubí, #62126 (1Ƥ, INBio).

Etymology. Name referring to the predominantly smooth frons, vertex and thoracic dorsum, from the Greek leios = smooth.

Distribution. Costa Rica.