Life history aspects of the lentic caddisfly, Nectopsyche albida (Walker), were investigated in the field and laboratory using systematic observational and conventional collecting methods. A two cohort population could be recognized based on field collections of approx. 110,000 adults and 2000 larvae made during 1975-1976.Premating swarming is described and consists of "figure 8" display flights performed by males at dusk and dawn. Attracted females then enter the swarm and select a mate. Sperm transfer is completed via a spermatophore in mid-air.Selection of aquatic vascular plants with suprasurface shoots as an oviposition site is favored over areas of water lacking such cues. Hatching larvae disperse to the shallows to develop. Bylate autumn predominantly fifth-instar larvae remain and these return to the deeper waters of the pond to overwinter on the aquatic plant, Myriophyllum exalbescens Fernald. Only about 20% of these late instar larvae move to the shallows to pupate during late spring.New records of nematode (Mermithidae) and water mite (Pionidae) infestations of the adults are also reported.