Food habits of two larval flies (Dolichopodidae: Diptera) in two Gulf Coast oligohaline tidal marshes

Food habits of two species of dolichopodid fly larvae, from two Gulf Coast oligohaline tidal marshes, were analyzed from monthly collections taken between June 1979 and May 1980. Larvae of Pelastoneurus abbreviatus Loew and Thinophilus frontalis Van Duzee, taken from a Juncus roemerianus Scheele dominated marsh, fed predominantly on oligochaetes and nematodes. Pelastoneurus abbreviatus, collected in a nearby Spartina cynosuroides (L.) Roth marsh, also fed on oligochaetes but consumed more polychaetes than nematodes. By being predators and prey in turn, these larvae serve in the transfer of energy between benthic, aquatic, and terrestrial components of the marsh system.