Microdon megalogaster

12–14 mm (0.47–0.55 in) The eyes are bare and the front of the face shines metallic greenish, sometimes blackish green.

On each side of the face, there is an oval, impressed orbital area on the upper fourth that is less distinct in the female.

The third segment of the antennae has the sides almost parallel, slightly curved upwards apically, the end rounded below, and subpointed above.

The thorax of this species displays a metallic greenish color with four or six obscure bluish stripes.

The scutellum is of a metallic bluish shade and has each angle broadly rounded, with a slightly excavated apex.

The wings are usually slightly brownish tinged, the cross-veins more or less clouded and luteous; the last section of the fourth vein is strongly recurrent, joining the third slightly before the tip of the second; the last section of the fifth vein is bulbous posteriorly, joining the fourth at a right angle.