LIFE-HISTORY, PRODUCTION AND FOOD OF APHROPHILA-NEOZELANDICA (DIPTERA, TIPULIDAE) IN A NEW-ZEALAND STREAM

The tipulid Aphrophila neozelandica (Edwards) (Limoniinac:Eriopterini) had a univoltine life cycle in a stony, montane stream in New Zealand . Growth of the larval population was well synchronized with most firs t instar larvae appearing in late December (early summer) and pupating the following spring (October-November). Light trapping indicated tha t adults were most abundant in late November-early December. Productio n was estimated at 0.56 g dry weight/m(2)/yr. Densities of larvae in t he two months when they were most abundant were not associated signifi cantly with water depth or water column current velocity within the ra nges 6-33 cm and 23-112 cm/s, respectively. Gut contents of late insta r larvae were principally filamentous algae, diatoms and plant detritu s. The presence in foreguts of ''balls'' of algae, and a general absen ce of silt or sand suggests that larvae ingest materials projecting ab ove substrate surfaces, rather than grazing surfaces closely.