Fannia abdominiseta sp. nov.

(Figs 2, 3A, 4A, 5A, 6A, 16)

Diagnosis. Fore tarsomere 1–4 white-yellowish, tarsomere 5 brown (Fig. 2D). Mid basitarsus enlarged ventrally. Hind coxa bare. Hind femur slightly curved with pre-apical swelling on v surface, with a tuft of five long pv setae (twice longer than width of femur) on the swelling, becoming shorter towards base, and connected to a row of pv setae reaching the base of the femur (Fig. 2F). Wing hyaline (Fig. 2C). Syntergosternite with 5 long lateral setae (the two most dorsal are curved and twice longer than sternite 5) (Fig. 2C).

Description. Male. Body length: 6.2 mm. Wing length: 5.8 mm.

Head. Eye short and sparsely setulose. Ocellar triangle dark brown; ocellar setae proclinate and developed (as long as frontal setae). Frontal vitta velvety brownish to black with silver pruinosity, at the narrowest point twice wider than width of anterior ocellus (Fig. 2A). Frontal setae 18. Fronto-orbital plate dark brown to black with silver pruinosity. Parafacial bare, brownish with silver pruinosity. Frontogenal suture and gena silver pruinose. Gena brownish to black with silver pruinosity, central area yellow (Fig. 2A). Pedicel with dorsal seta developed, length about a third of arista. Postpedicel black, silver pilose.

Thorax. Scutum without vittae, inconspicuously silver pruinose on postpronotal and notopleural regions (Fig. 2B). Acrostichal setulae triserial presuturally and triserial to quadriserial postsuturally. Dorsocentrals 2+3, long, posterior-most postsutural pair slightly longer than the others. Prealar 2, anterior one slightly longer. Katepisternum with about 10 long and thick setae ventrally (Fig. 2C).

Wing. Hyaline (Figs 2B, 2C). Calypters white. Haltere brown with stem light brown to yellow.

Legs. Light brown. Pulvilli light brown. Tarsi brown, except for fore tarsomeres 1–4, white-yellowish (Fig. 2D). Fore tarsomeres 1 and 2 slightly enlarged laterally (Fig. 2D). Fore tarsomeres 5 with 3 long d setulae (Fig. 2D). Mid femur with 1 row of ad to d setae, with 1 row of decreasing av from base to apex; 1 row of long p and pv setae (thicker on the apical third) (Fig. 2E). Mid tibia with 1 submedian ad, 1 median pd, 1 strong and long preapical d, 1 apical seta on a, ad, p, pv, and v (v longer, similar to d preapical seta) (Fig. 2E). Mid basitarsus enlarged ventrally. Hind coxa bare on posterior margin. Hind femur slightly curved with pre-apical swelling on v surface, with tuft of long setae on pv surface, setae contiguous with row decreasing in length basally, 3 long preapical ad setae, 1 row of av setae (absent on the pre-apical swelling), 1 long preapical av setae, 1 preapical ad and pd (Fig. 2F). Hind tibia with 2 median av; 1 submedian ad; 1 apical seta on av (Fig. 2F).

Abdomen. Metallic light brown with silver pruinosity, elongate, with developed setae, tergite 5 with long marginal setae (slightly longer than the others). Syntergosternite with 5 lateral setae, the two dorsalmost longer and curved (Fig. 2C). Sternite 5 V-shaped, posterior margin profoundly indented (Fig. 3A).

Terminalia.Surstylifusedwithepandrium.Surstylislightlyenlargedandcurvedapically(Figs4A, 5A).Bacilliform process long and simple, as long as half of the surstyli (Fig. 4A). Hypandrial arms directed outwards (Fig. 6A).

Female. Unknown.

Etymology. The specific name is derived from the Latin words abdomen (“abdomen”) and seta (“bristle”), it refers to the long setae on the syntergosternite.

Type-material. Holotype. Male. Mexico. Hidalgo. Parque Ecológico El Chico, Mineral El Chico, 20°10′58′′N, 98°43′04′′W, 9.vi-16.vii.2019, Trampa aérea 3, Nuple, E. (CNIN) . Paratype. Same as holotype, except: trampa aérea 6, 1 male (CARF, CPL2924) .

Distribution. Mexico (Hidalgo).

Remarks. F. abdominiseta is similar to F. anguliseta sp. nov. but can be easily distinguished from the latter by the hyaline wing.