Dentalion alveum sp. nov.

(Figs 2–5, 56)

Diagnosis. Midlobe of mesoscutum with posterior ½ smooth except for a few strong foveae (Fig. 4) and with posterior 2/3 of notauli as row of pits; frontal suture reaching eyes below anterior ocellus at a distance equal to 1.5X diameter of an ocellus (Fig. 2); forewing costal cell bare (as in Fig. 52); propodeum smooth, callus with 4 or 5 setae.

Description. FEMALE. Length 0.8–1.7 mm. Antenna dark brown. Frons below frontal suture golden-green; above frontal suture metallic purple. Vertex golden-green with dark brown parts inside ocellar triangle, outside dark brown. Mesoscutum metallic bluish-green. Scutellum with anterior ½ metallic purple, posterior ½ metallic bluish-green. Propodeum metallic bluish-purple. Coxae dark and metallic; femora and tibiae dark brown; tarsi with tarsomeres 1–3 white, 4 dark brown. Forewing hyaline. Gaster dark brown with metallic purple, blue and green tinges.

Antenna as in Fig. 56. Frons smooth below frontal suture close to scrobes and close to eyes (Fig. 2), but with raised, strong reticulation between the smooth areas and with raised, weak reticulation above frontal suture; frontal suture reaching eyes below anterior ocellus at a distance equal to 1.5X diameter of an ocellus. Vertex with raised, rather strong reticulation (Fig. 3) except smooth lateral to posterior ocelli. Occipital margin rounded. Eyes with sparse, scattered hairs (Figs 2, 3).

Pronotum without transverse carina close to posterior margin (Fig. 4). Mesoscutum with raised, weak reticulation (Fig. 4), midlobe with posterior ½ smooth except for a few strong foveae; notauli as narrow distinct grooves in anterior 1/3, and as row of pits in posterior 2/3. Scutellum with raised, weak reticulation (Fig. 4) except median, lateral, and posterior parts with very weak reticulation to smooth; with 1 pair of setae. Propodeum smooth (Fig. 5); callus with 4 or 5 setae. Forewing speculum closed below; costal cell bare.

Petiole 0.2X as long as wide, smooth. Gaster ovate with apex acuminate; tergites smooth.

MALE. Unknown.

Material examined. Holotype female (BMNH) labelled “ COSTA RICA, Guanacaste, Parque Nacional Santa Rosa, 300 m, 14.vi–5.vii.1986, D.H. Janzen & I.D. Gauld”. Paratypes. 2Ψ on cards. COSTA RICA. Guanacaste: from same locality as holotype but collected 8.ii–2.iii.1986 (1Ψ, INBio); Puntarenas: Los Charcos de Osa, 08˚40'N 83˚30'W, 50 m, 15–16.ii.2010, J.S.Noyes (1Ψ, BMNH).

Etymology. Named for the foveae on midlobe of mesoscutum, from the Latin alveus = pit, fovea.

Distribution. Costa Rica.