Taxonomic group
Family: Dolichopodidae
Diagnostic features
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.
Typical habitats
Dolichopodid larvae are relatively rarely found in stream samples, but we have found them in soft bottom, freshwater and estuarine sites.
Feeding
Most dolichopodids overseas have predatory larvae and it is assumed this is the case in New Zealand.
Indicator value
- Hard bottom: 3
- Soft bottom: 8.6
The tolerance values (ranging from 0 to 10) give an indication of which are the sensitive taxa (values of 8 or more) and which are the tolerant taxa (values of 3 or less). For more information see: Indicator species
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).