The tipulidAphrophila neozelandica(Edwards) (Limoniinae:Eriopterini) had a univoltine life cycle in a stony, montane stream in New Zealand. Growth of the larval population was well synchronized with most first instar larvae appearing in late December (early summer) and pupating the following spring (October‐November). Light trapping indicated that adults were most abundant in late November‐early December. Production was estimated at 0.56 g dry weight/m2/yr. Densities of larvae in the two months when they were most abundant were not associated significantly with water depth or water column current velocity within the ranges 6–33 cm and 23–112 cm/s, respectively. Gut contents of late instar larvae were principally filamentous algae, diatoms and plant detritus. The presence in foreguts of “balls”; of algae, and a general absence of silt or sand suggests that larvae ingest materials projecting above substrate surfaces, rather than grazing surfaces closely.