Galeopsomyia ventrosa Hansson sp.nov.

(Figs 618, 619, 1100)

Diagnosis (female). Antennal clava with a weak constriction between C1 and C2 (Fig. 1100); genal carina present; mesoscutellum (Fig. 618) with weak reticulation on median part and with a weak median groove in anterior two-thirds, lateral parts with strong reticulation, meshes elongate, submedian grooves distinct, straight and parallel; dorsellum with median carina; propodeum (Fig. 618) medially with a few strong irregular carinae, laterally with strong reticulation, callus with six setae; petiole transverse with strong sculpture on dorsal surface; gaster (Fig. 618) 3.1× as long as wide, medio-basal Gt1 with longitudinal sharp edges laterally, tergites with strong reticulation.

Female holotype: length of body 3.0mm.

Scape yellowish-brown, pedicel pale brown, flagellum dark brown. Face below level of toruli golden-green, clypeus dark brown, frons metallic bluish-green, antennal scrobes black. Thoracic dorsum metallic bluish-green. Legs with fore coxa dark brown with metallic blue tinges, mid coxa dark brown, hind coxa golden-green; trochanters dark brown; femora dark brown with apex yellowish-brown; tibiae yellowish-brown; T1–3 yellowish-brown, T4 pale brown. Petiole black. Gaster with Gt 1 golden-green, Gt2-5 golden-purple, Gt6 metallic bluish-green, Gt 7 black; gonoplac black.

Antenna with a weak constriction between C1 and C2. Face below level of toruli with weak reticulation, clypeus smooth, frons rugose, antennal scrobes with weak reticulation; with genal carina. Vertex with strong reticulation outside ocellar triangle, with wrinkled sculpture inside ocellar triangle. Occipital margin with a carina behind ocellar triangle.

Mesoscutum with strong reticulation, meshes isodiametric on sidelobes, elongate on midlobe, midlobe rugose close to notauli; midlobe with a median groove in posterior two-thirds, with 16 scattered setae on rugose parts. Mesoscutellum with weak reticulation on median part and with a weak median groove in anterior two-thirds, lateral parts with strong reticulation, meshes elongate; submedian grooves distinct, straight and parallel; with six setae scattered over lateral parts. Dorsellum with strong reticulation, with median carina. Propodeum medially with a few strong irregular carinae, laterally with strong reticulation; callus with six setae. Fore and hind coxae with strong reticulation, mid coxa with weak reticulation. Fore wing with 4&5 setae on dorsal surface of submarginal vein; speculum closed; costal setal row broken.

Petiole transverse with strong sculpture on dorsal part. Gaster elongate; medio-basal Gt 1 with longitudinal sharp edges laterally; tergites with strong reticulation.

Relative measurements: head length, dorsal view 26; head length, frontal view 45; POL 11; OOL 7; lateral ocellus diameter 6; head width 59; mouth width 20; malar space 17; eye length 27; scape length 21; scape width 5; pedicel+flagellum length 62; pedicel length 8; pedicel width, dorsal view 4.5; F1 length 9; F1 width 6; F2 length 10.5; F2 width 6; F3 length 10; F3 width 6; clava length 21.5; clava width 6.5; C3 length 7; spicule length 2; mesosoma length 80; mesosoma width 60; midlobe of mesoscutum length 33; mesoscutellum length 29; mesoscutellum width 27; median part of mesoscutellum width (measured medially) 11.5; median part of mesoscutellum, width in anterior part11.5; median part of mesoscutellum, width in posterior part 12; lateral part of mesoscutellum, width (measured medially) 5.5; dorsellum length 4; propodeum length 12; costal cell length 41; costal cell width (measured at widest part) 3; marginal vein length 34; stigmal vein length 11; gaster length 137; gaster width 44; Gt 2 length (measured medially) 11; Gt 4 length (measured medially) 18; Gt 7 length (measured medially) 26; Gt 7 width (measured at base) 16; longest cercal seta length 16; shortest cercal seta length 7.

Male. Unknown.

Hosts. Reared from leaf galls (swelling of veins) induced by an unidentified Agromyzidae ( Diptera) on Casearia commersoniana ( Salicaceae).

Distribution. Costa Rica.

Material examined.

Holotype ♀ COSTA RICA, San José, Universidad de la Paz, xii.2004, from agromyzid leaf gall on Casearia comers., P. Hanson (NHMUK).