1	Frons and parafacial barely visible laterally (Fig. 85). Height of lunule ~ 0.6–0.8 × width. First flagellomere small and short. Basal 1/2 of oviscape pruinose. Height of eye divided by height of gena: 3.9–4.7. Sperm pump pointed ventrally (Fig. 418). Distiphallus narrow, bifid, and twisted counterclockwise; spicules on membrane small and apical (Figs 423, 424)	A.flavifrons (Meigen)
–	Frons and parafacial strongly projecting, continuing as prominent cheek (Fig. 87). Height of lunule < 1/2 width. First flagellomere 0.3 × longer than wide. Oviscape entirely shiny. Height of eye divided by height of gena: 1.6–3.1. Sperm pump broadly and evenly rounded. Distiphallus globular and very dark; sometimes divided, but not bifid; spicules on membrane small to large and extending along length of distiphallus	2
2	Halter mostly brown. Thorax brown with very light pruinosity. Head brown with gena, lunule and centre of frons paler. Two ors. Ocellar seta as long as postocellar. Vibrissa well-developed. Epistoma ~ 2/3 × length of clypeus with anterior margin relatively straight. Head not strongly projecting anterodorsally and eye not reduced in size (height of eye divided by height of gena: 2.3–3.1). “Bowl” of ejaculatory apodeme wider than blade of ejaculatory apodeme; stem relatively wide (Fig. 414). Distiphallus undivided and somewhat rounded (Figs 415–417)	A.abnormalis (Malloch)
–	Halter completely white. Thorax covered with dense silvery-grey pruinosity. Head almost entirely light yellow (Figs 86, 87). One ors. Ocellar seta barely longer than ocellar tubercle. Vibrissa similar to genal setae. Epistoma at least as long as clypeus and strongly tapered anteriorly. Head strongly projecting anterodorsally and eye very small (height of eye divided by height of gena: 1.6–1.8). Sperm pump narrower than blade of ejaculatory apodeme; stem relatively narrow (Fig. 428). Distiphallus divided medially, narrower at base (Figs 426, 427)	A.karli (Hendel)