Grotiusomyia albiclava sp. nov.

Figs 3, 21, 22, 49, 50, 78, 95

Diagnosis. Female: mandibles yellowish-brown with a row of small teeth at apex (as in Fig. 112); flagellum 1.3× as long as width of mesoscutum, F4 1.8× as long as wide, apex of clava pointed, F1–F4 dark brown, clava white (Figs 3, 50); frons between scrobes and eyes and vertex with weak and engraved reticulation (Fig. 95); occipital margin with a sharp carina throughout (Fig. 78); mesoscutum and mesoscutellum with same colour and reticulation (Fig. 21); mesoscutellum convex; dorsellum flat, smooth and shiny, posterior margin evenly rounded with small dents; fore wing with 3–6 setae in apico-dorsal part of costal cell, completely hyaline (Fig. 3); fore coxa white, mid coxa yellowish-brown with median part black (Fig 3); gaster (Fig. 21) 1.7× as long as wide; Gt 1 0.6× as long as length of gaster, dorsal surface with strong reticulation, meshes elongate, posterior margin curved slightly forwards; Gt 6 0.1× as long as length of gaster with anterior part 1.4× as wide as width of posterior part, posterior margin straight with sharp edge. Male: entire antenna and gaster dark brown (Figs 22, 50); Gt 1 with strong reticulation (Fig. 22).

Description (female holotype). Length 1.8 mm. Frons and vertex with weak and engraved reticulation and shiny, scrobes smooth, frons with a few scattered setae between scrobes and eyes. Mandibles with a row of small teeth at apex. Occipital margin with a sharp carina throughout. Dorsellum flat, smooth and shiny, posterior margin ±evenly rounded with small dents. Propodeal callus with nine setae. Fore wing with five setae on dorsal surface of submarginal vein; with 17 admarginal setae; costal cell with 14 setae on ventral surface, in a single row, apico-dorsal margin with five setae; speculum small and closed below. Gaster long ovate; Gt 1 with strong reticulation, meshes elongate, remaining tergites with weak reticulation; Gt 1 with posterior margin curved slightly forwards, Gt 6 with posterior margin straight.

Colour. Head metallic green, scrobes and part below level of toruli black with metallic tinges. Mandibles yellowish-brown. Antennae with scape yellowish-brown, pedicel pale brown, F1–F4 dark brown, clava white. Mesosoma black with metallic tinges. Legs with fore coxa white, mid coxa yellowish-brown with median part black, hind coxa black with metallic tinges; trochanters yellowish-white; femora, tibiae and tarsi yellowish-brown. Gaster with Gt 1-3 black with metallic tinges, remaining tergites brown.

Relative measurements: head length, dorsal view 19; head length, frontal view 29; head width 44; POL 9.5; OOL 5; mouth width 19; malar space 4; eye length 23; lateral ocellus diameter 3; scape length 18; scape width 4; pedicel length 7; pedicel width. dorsal view 3; flagellum length 47; F1 length 8.5; F1 width 3; F2 length 8; F2 width 4; F3 length 9; F3 width 4.5; F4 length 8; F4 width 4.5; clava length 14; clava width 4; pronotum length 16; pronotum width 28; mesosoma length 60; mesosoma width 37; midlobe of mesoscutum length 14; mesoscutellum length 20; mesoscutellum width 19; propodeum length 14; hind tibia length 41; hind tibial spur1 length 8; hind tibial spur 2 length 3.5; hind tarsus length 31; hind basitarsus length 8.5; fore wing length 107; fore wing width 44; costal cell length 30; costal cell width 1.5; marginal vein length 35; postmarginal vein length 13; stigmal vein length 9.5; Gt 1 length 35; Gt 6 length 5; Gt 6 width at base 14; Gt 6 width at apex 10; gaster length 62; gaster width 37.

Variation. Length of body 1.4–1.8 mm. Costal cell with 3–6 setae in apico-dorsal part. Propodeal callus with 8–10 setae.

Male. Length 1.1–1.6 mm. Entire antennal flagellum dark brown. Otherwise as in female.

Relative measurements: head length, dorsal view 16; head width 39.5; eye length 20; scape length 18; scape width 4; flagellum length 62; F1 length 11; F1 width 5; F2 length 11; F2 width 5.5; F3 length 12; F3 width 6; F4 length 11.5; F4 width 6; clava length 17; clava width 5; Gt 1 length 32; gaster length 50; gaster width 30.

Distribution. Costa Rica.

Etymology. From the Latin albus = white, and clava = club, referring to the white antennal clava in female.

Material. Holotype female: COSTA RICA, Heredia, Estación Biológica La Selva, 50m, 10º26′N, 84º01′W, x.1995 (NHMUK) . Paratypes (13♀ 9♁, MZLU, MZUCR, NHMUK): 1♀ with same label data as holotype; following from same locality as holotype but collected 22.i-2.ii.1991 (2♁), 14.ix.1995 (1♀), xi.1995 (1♀), iii.1996 (1♀), 15.iv.1996 (1♁), 22-24.ii.2012 (1♀ 1♁); 1♀ COSTA RICA, Alajuela, 5km W San Ramón on Route 1, 1200m, iv.1997, P. Hanson ; 1♀ COSTA RICA, Cartago, Turrialba, CATIE, 700m, 21.ii.1991, J.S. Noyes ; 1♀ COSTA RICA, Guanacaste, Estación Cacao, 10º55′N, 85º30′W, 1100m, 19-20.ii.2005, J.S. Noyes ; 1♀ from same locality as previous but collected 1-9.iii.1996; 1♀ COSTA RICA, Guanacaste, Parque Nacional Guanacaste, below Pitilla, 500m, 7-8.iii.1990 , J.S. Noyes; 1♀ COSTA RICA, Limón, Reserva Biológica Hitoy Cerere, 9º40′N, 83º02′W, 100m, 24–25.ii.2004, J.S. Noyes; following from same locality as previous but collected 24-26.ii.2008 (1♀ 1♁), 22-23.ii. 2010 (1♁); 2♁ COSTA RICA, Puntarenas, Estación Altamira, Sendero Los Gigantes, 9º02′N, 83º00′W, 1450–1700m, 7.ii–5.iii.2002, C. Hansson & Parataxonomos; 1♁ COSTA RICA, Puntarenas, San Vito, Las Cruces, Wilson Botanico, 8º47′N, 82º58′W, 1000–1300m, 7-19.ii.2007 , C. Hansson; 1♀ from same locality as previous but collected 19–22.ii.2008 .