Recognition. This species can be recognized by the dark frons and the shape of the ovipositor, with its elongate, narrowed region (Fig. 63).

Description. Body length 2.1 mm. Frons black, to dark brown, lighter ventrally. Setal base of all setae coloured like rest of frons. Frons 0.33 head width; with fine reticulate sculpturing, slightly shiny, punctate, with small, black setulae. Median furrow present. Frontal setae normal; arrangement of frontal setae unmodified, with ventral interfrontal setae near venter of frons. Dorsal interfrontal setae present, 0.7 length of postocellar setae, slightly dorsal to level of dorsal fronto-orbital setae. Palpus unmodified. Ocular and genal setae flattened, yellow. Fore tarsomeres yellowish-brown, relatively narrow. Combined length of fore tarsomeres approximately 0.9 tibial length. Fore tarsomere 1 approximately twice as long as tarsomere 2. Fore tarsomere 5 relatively narrow. Pulvilli of fore leg relatively small. Tarsal claws of all legs enlarged, deeply bifurcate. Hind leg yellowish-brown, with tarsomeres 4–5 and apex of tarsomere 3 brown dorsally (mid legs missing). Costa 0.53 wing length. Tergite 6 of similar colour to other tergites. Tergites 2–6 lateroventrally black, with silver pollinosity. Venter of abdomen grey. Ovipositor relatively tubular, strongly narrowed on apical one-fifth. In dorsal view, lateral setae of ovipositor thin, short. Ventrally, ovipositor with thin setae. Surface of ovipositor with faint, irregular, reticulate sculpturing.

Geographical distribution. Ecuador.

Etymology. Latin adjective based on the diminutive form of anas, meaning duck, referring to the duck’shead shape of the ovipositor in lateral view.

Holotype. ♀, ECUADOR: Carchi: Chical, 0.93∞N, 78.18∞W, 12.viii.1983, J. E. Rawlins, 1250 m [CMNH 238905] (Carnegie Museum of Natural History).

MELALONCHA ANGUSTIFRONS SP. NOV.

(FIGS 16, 58, 64)

Recognition. This species can be recognized by the lack of dorsal interfrontal setae, narrow frons, and the shape of the ovipositor (Fig. 58).

Description. Body length 2.6–3.5 mm. Frons orange, except vertex and ocellar region, which are black. Setal base of all setae coloured like rest of frons. Mean frontal width 0.19 head width; range 0.17–0.21. Frons with fine reticulate sculpturing, not shiny, punctate, with small, pale setulae. Median furrow faint, but present. Frontal setae normal; arrangement of frontal setae unmodified, with ventral interfrontal setae near venter of frons. Dorsal interfrontal setae absent. Palpus unmodified. Ocular and genal setae flattened, yellow. Fore tarsomeres yellowish-brown, relatively narrow. Combined length of fore tarsomeres approximately 0.8 tibial length. Fore tarsomere 1 approximately twice as long as tarsomere 2. Fore tarsomere 5 slightly expanded. Pulvilli of fore leg large. Tarsal claws of all legs small, finely bifurcate at apex. Mid and hind leg yellowish-brown, with tarsomeres 4–5 and apex of tarsomere 3 of mid leg dark brown dorsally. Mean costal length 0.55 wing length; range 0.53–0.57. Tergite 6 of similar colour to other tergites. Tergites 2–6 lateroventrally black, with silver pollinosity. Venter of abdomen grey. Ovipositor relatively tubular, slightly deflected ventrally at apex. In dorsal view, lateral setae of ovipositor large, relatively fine, widely spaced. Ventrally, ovipositor with short, fine, sparse setae. Surface of ovipositor with faint, irregular, reticulate sculpturing.

Variation. The specimen from Bolivia is much larger than the Costa Rican individuals, but is apparently otherwise similar in structure.

Geographical distribution. Costa Rica and Bolivia.

Etymology. Latin adjective based on angustus for narrow, referring to the shape of the frons.

Holotype. ♀, COSTA RICA: Puntarenas: Las Alturas, 8.95∞N, 82.83∞W, xii.1991, P. Hanson, Malaise trap, 1500 m [LACM ENT 003714] (LACM).

Paratypes. BOLIVIA: La Paz: near Chulumani, Apa Apa Reserve, 16.37∞S, 67.51∞W, 1♀, 1–3.iv.2001, B. Brown, G. Kung, Malaise trap #5 (LACM). COSTA RICA: Cartago: Parque Nacional Tapanti, 9.76∞N, 83.77∞W, 1♀, ii.1995, G. Mora, Malaise trap #4506, 1150 m (INBC); Puntarenas: Las Alturas, 8.95∞N, 82.83∞W, 1♀, vi.1992, P. Hanson, Malaise trap, 1500 m (LACM).