The two species with cosmopolitan distributions are associated with the movement of trade goods (Scenopinus fenestralis and S. glabrifrons).

The adults are small insects, usually with the body no longer than 5 mm, glabrous or slightly hairy and with blackish livery.

The mouthparts are of the sucking type with the labrum (proboscis) very short and with a fleshy apex, and one- or two-segmented maxillary palps.

The wing venation differs substantially from that of Therevidae by the number of branches of the media which are reduced to two or three and from that of Bombyliidae in having a simpler radial system.

The entire radial system is positioned in the front half of the wing, without going beyond the axis that connects the base with the apex.

M 2 is missing in the majority of the Scenopininae, but it is present in the Proratinae in Cyrtosarthe and Caenotus and runs into on the posterior border.

Frequently, however, they are, always as predators, in other habitats, such as wood and other substrates, decomposing organic, dens and nests of mammals and birds, and sometimes domestic environments.

Asilidae Bombyliidae Clade showing relationship of Asiloidea The oldest known member of the family is Burmaprorates alagracilis from the mid Cretaceous Burmese amber of Myanmar, which belongs to the subfamily Proratinae.