Diel drift of Chironomidae larvae in a pristine Idaho mountain stream

摘要: Simultaneous hourly net collections in a meadow and canyon reach of mountain stream determined diel spatial abundances drifting Chironomidae larvae. Sixty-one taxa were identified to the lowest practical level, 52 41 canyon. Orthocladiinae was most abundant subfamily with 32 24 h mean density 294 individuals 100 m−3 (meadow) 26 648 (canyon). Chironominae second subfamily. Nonchironomid invertebrates at both sites total larvae predominantly night-drifting. Parakiefferiella Psectrocladius day-drifting whereas 8 other chironomid 2 (canyon) All others aperiodic or too rare test periodicity, Stempellinella cf brevis Edwards exhibited catastrophic drift only. The different patterns between is attributed greater loss streambed habitat compared as streamflow decreased. Consequent crowding caused interfered periodicty. This study adds knowledge shows influences on hydrologic geomorphic conditions.