Type-species: Hypocera difformis Brues (by original designation)
Hypocerides Schmitz 1915a: 496. Refs.: Schmitz 1915b: 329, 1927: 65, 1929: 117, 1937: 110; Borgmeier 1926: 115, 1966: 122; Beyer 1965: 17; Borgmeier & Prado 1975: 38 (hypopygium illustration); Disney 1991: 271 (key); Disney & Blasco-Zumeta 2004: 307 (biology); Klocke et al. 2011: 10 (biology).
Diagnosis. Palps with dorsal sensory pits (Fig. 2A–D), costa swollen between R 1 and R 4+5, veins posterior to the radial system weak (Fig. 4), hind tibia with one dorsal setal palisade, frons with dorsal fronto-orbitals absent (Fig. 3).
Description. (males) Body brown, body length, 1.25–2.2 mm. Frons pubescent, generally with median area bare, with sparse thin setulae, without median furrow, setation 4-2-4 (dorsal fronto-orbitals absent), with two dorsally directed supra-antennal setae (Fig. 3). Palpus bearing strong setae near apex, with dorsal excavation bearing short and long sensilla (Fig. 2A–D). Flagellomere 1 pubescent, globose, with subcutaneous pit sensilla (SPS). Arista pre-apical, pubescent; aristomeres 1-2 short; no lower genal and one upper genal tiny setula. Anepisternum bare, without furrow (proepimeron not enlarged dorsally and posteriorly); lateral parapsidal suture of medium extension (not ending far from the anterior spiracle); meron concave. Scutellum with two pairs of setae on posterior margin. Foretibia with anterodorsal row of slightly stronger setulae. Foremetatarsus width/length ratio, 0.18–0.22. Midtibia basal half with one anterodorsal and one posterodorsal setae. Hind femur not expanded dorso-ventrally (height/ length ratio 0.25), with group of elongated microtrichia near base of posterior face and ventral band of differentiated setulae (Fig. 2E–H). Hind tibia without large setae except the apical ones, with a dorsal setal palisade. Wing venation relatively uniform within the genus (Fig. 4), costa swollen between the apices of R 1 and R 4+5, 0.35–0.42 of the wing length; R 2+3 absent; M 1 and M 2 slightly sinuous; CuA 1 sinuous. No seta at Rs base. Tergites dark brown, with lighter posterior band. Epandrium short, with surstyli forming a U-shaped subcercal process (Fig. 5A–G). Epandrial right posterior margin with subepandrial group of setulae. Hypandrial lobes large; left lobe wider, with posteroventral margin projected posteriorly. Insertion of phallapodeme and of the hypandrium lobes shifted to left lateral. Hypoproct with two setae. Basiphallus with two posterodorsal horns (Fig. 6A–E). Right plate extending ventrally and reaching the left lateral. Epiphallus connected to the right plate at the left lateral, bearing pointed scales and with a slender curved projection. Curved posterior process bearing multi-pointed scales.
(females) Similar to males, but with tergites 3–6 reduced (Fig. 7A–E). Oviscape short. Tergites and sternites 7 and 8 apparently absent (Fig. 7F–K). Ventral margin of segment 8 with an anterior reentrance. Cerci cylindrical.
Geographical distribution. The genus is known from few scattered records through all biogeographic regions except the Antarctic (Fig. 8).
Comments. Borgmeier (1966) described the genus as having 2-4 scutellar setae. Disney (1991), however, interpreted all species as having four scutellar setae. Borgmeier (1966) also considered the frontal setation 4-2-4 or 4-4-4 for the genus. As illustrated herein, H. anheuseri, which would have 4-4-4 according to Borgmeier, has the setation 4-2-4 (Fig. 3). I referred to the frontal setation of all examined specimens as 4-2-4 (dorsal frontal-orbitals absent) and not 2-4-4 (ventral interfrontals absent). However, I found no clear evidence that the fronto-orbitals present are the ventral ones. The fronto-orbitals in Hypocerides are sometimes in a position more similar to the dorsal frontoorbitals (Fig. 3, H. anheuseri) and sometimes to the ventral fronto-orbitals (Fig. 3, H. nearcticus).