Adults longlegged flies are predaceous, feeding primarily on small, soft-bodied arthropods and annelids, and are important natural enemies of pests in a variety of habitats including agroecosystems. Adult and larval forms of Diptera are their most favored prey, especially Chironomidae and Culicidae, followed by Homoptera, Collembola, mites and Thysanoptera. Other documented prey items include annelids, cladocerans, amphipods, small myriapods, odonate eggs, termites, psocopterans, beetle larvae, early instar caterpillars, dead and wounded arthropods and amphibian embryos.

Although the adults of some dolichopodids are known to use their forelegs to hold and manipulate their prey, most grab and masticate prey with their epipharynx and labellum, suck up the liquids and discard the remains. In addition to feeding on live prey, many dolichopodids have also been observed taking up honeydew, and it is thought that most species do so in order to obtain carbohydrates. Adults of some Dolichopodinae have elongate mouthparts and are known to be anthophilous and feed on nectar."
--North American Dipterist Society, Empidoid Resources