The dolichopodid flies are not well known in New Zealand fresh waters. Their aquatic larvae may be mistaken for empidids as they are small and maggot-like, with a fully retracted head, and with caterpillar-like welts along the abdomen. Dolichopodid larvae however, have fleshy lobes at the end of the abdomen resembling the spiracular discs of tipulid cranefly larvae.
Dolichopodid larvae are relatively rarely found in stream samples, but we have found them in soft bottom, freshwater and estuarine sites.
Most dolichopodids overseas have predatory larvae and it is assumed this is the case in New Zealand.
Dolichopodid larvae have been found in streams with moderate to good water quality. They have widely varying tolerance values of 3 (hard bottom sites) and 8.6 (soft bottom sites).