[5][6] The genus Apterostigma was described by Gustav Mayr (1865), from winged male and female specimens collected in southern Brazil.

Head elongated, without isolated spines or denticles; Ventrally the eye is bordered by a convexity, the vertex extending into a sheet that delimits the occipital zone and forms a neck of variable length and width.

the first tergus of the gaster presents on each side a longitudinal edge of variable development; the gaster generally presents a finely granulated cuticle, sometimes rough; with roughness or small piliferous papillae; never with prominent denticles or tubercles.

head long; generally devoid of spines or denticles, except for some species with two low tubercles on the forehead and between the eyes.

With the head in frontal view, the posteromedian profile generally presents a low emargination or at least a flat area; the posterolateral profile may be evenly convex or have a semi-hexagonal posterior profile to the eyes; a straight and vertical section posterior to each eye separated by a rounded angle from another straight and inclined section, which in turn is separated by a rounded angle, or sometimes an ridge, from the posteromedian emargination.

The clipeo rises posteromedially to form a convexity bordered posteriorly by the frontal lobes; occasionally the frontoclypeal suture is evident.

As we already mentioned, these are only from America, so they correspond to the Neotropical region, to be more specific they can be found in the Mexican, Brazilian subregion, and in a few parts of the Andean, as well as in the Patagonian.