Female

Length 8.7 mm. Wing 8.1 mm.

Head (Fig. 1c). Frons wide, grey, with black hairs, wider at the base than at the vertex. Frontal index 2.2, divergence index 0.6. Frontal callus dark brown triangular, bare and shiny narrower than frons. Subcallus, clypeus and gena with yellowish-grey pruinescence, tentorial pits bare and shiny. Gena with sparse hairs, dark in the anterior half and light in the posterior half. Antennae (Fig. 1d) with long spine, not reaching the end of postpedicel. Scape, pedicel and postpedicel dark yellow and darker towards the apex, with dark hairs and greyish purinescence. Palpus long and slender, light brownish-yellow with black hairs. Prementum dark brown and labellum brown to black, sclerotised, both with black hairs.

a

b

c

d

e

Figure 1.

Dichelacera (dichelacera) lamasi sp. n., holotype ♀.

a: Dorsal view.  
b: Lateral view  
c: Head, frontal view.  
d: Antenna.  
e: Wing.  

Thorax (Fig. 1a). Anterior half of scutum brown with greyish-brown pruinescence, sparse dark and light hairs. Interalar band wide dark brown with hair loss because the specimen was preserved in alcohol and then pinned. Lighter prescutellar band with grey pruinescence and yellow hairs, scutellum dark brown with dark hairs. Pleura with brown integument, grey pruinescence with brown hairs. Halteres light yellowish-brown. Fore and midleg light brown, hind leg brown. All legs with dark hairs, except for fore and midcoxa with light hairs. Tarsomeres dark brown with black hairs. Wing (Fig. 1e) with narrow dark brown fascia, inner margin sinuous. Cell cua with darkening in the anterior half.

Abdomen (Fig. 1a). First tergite brown, tergites 2-7 brown with whitish narrow lateral and posterior bands slightly enlarged in the middle on tergites 2-5. Light bands of tergites with light hairs and dark areas with dark hairs. Sternites brown with whitish posterior bands. Sternites 2-5 with light and dark hairs. Sternites 6-7 with dark hairs.

Male. Unknown

Small species, mostly brown. Dorsal spine of the antenna elongated, but not reaching the apex of the first flagellomere. Tentorial pits bare and shiny. Frons convergent at the vertex. Frontal callus narrower than the frons. A large dark interalar band on scutum, but little contrasting. Dark abdomen with narrow clear posterior bands.

The specific name is in honour of the Brazilian dipterologist Dr. Carlos Lamas, researcher at Museu de Zoologia da Universidade de São Paulo, who collected the material.