Description
Eumerus species are small to medium (5–12 mm), black hoverflies with a smooth wide, almost cylindrical body. The hind legs are remarkably powerful. They have compound eyes with fine hairs that in the male cover most of the head, but in the female are parted over the forehead. The antennae are quite short, dark coloured or orange. The face is flat with downwardly directed hairs. The thorax has a few light longitudinal stripes on its back which are more visible in the front half. The legs are yellowish, or white and black, with the upper back legs usually greatly thickened (except Eumerus flavitarsis), the lower part being curved and sharp, with expanded feet. The abdomen is roughly cylindrical, and clearly constricted at the boundaries between the various parts. The second, third and fourth part has silvery white or yellow oblique spots. In some species, the entire abdomen is a reddish brown. The wings are covered with fine hairs (microtrichia) on the entire surface. Otherwise they are clear except for a brown-black wing mark. The front cross-vein along the outer edge of the wing has a pronounced kink in the middle.
