Life History and Feeding Habits of a Lentic Caddisfly in Coeur d'Alene Lake
Additional Funding Sources
The project described was supported by a student grant from the UI Office of Undergraduate Research.
Abstract
The lentic case-building caddisfly, Nectopsyche albida, occurs in Coeur d’Alene Lake although it is currently listed as “does not occur” in Idaho by the Idaho Department of Fish and Game. Outside of a recently completed MS thesis, little is known about its ecology, life cycle, or role in ecosystems across the Pacific Northwest, aspects of which were the focus of my study. I collected 5th instar larvae and pupae from Chatcolet Lake at the southern end of Coeur d’Alene Lake which were used to i) examine feeding preferences and rates of macrophyte consumption including the non-native Eurasian/northern milfoil hybrid, and ii) examine duration of pupal and adult life stages and to observe hatching of egg masses. Feeding results indicated they were opportunistic generalists, while ovipositing required a large enclosure to allow the caddisflies sufficient space to ‘swarm’ above the water. Pupation times varied from 17 days to more than 20, with most 5th instars beginning their pupal phase by late June. Investigating the timing of the N. albida life cycle and how it coincides with the growth of macrophytes, native and introduced, provides insights into the larger ecosystem of Chatcolet Lake and the interactions between the caddisfly and macrophyte communities.
Life History and Feeding Habits of a Lentic Caddisfly in Coeur d'Alene Lake
The lentic case-building caddisfly, Nectopsyche albida, occurs in Coeur d’Alene Lake although it is currently listed as “does not occur” in Idaho by the Idaho Department of Fish and Game. Outside of a recently completed MS thesis, little is known about its ecology, life cycle, or role in ecosystems across the Pacific Northwest, aspects of which were the focus of my study. I collected 5th instar larvae and pupae from Chatcolet Lake at the southern end of Coeur d’Alene Lake which were used to i) examine feeding preferences and rates of macrophyte consumption including the non-native Eurasian/northern milfoil hybrid, and ii) examine duration of pupal and adult life stages and to observe hatching of egg masses. Feeding results indicated they were opportunistic generalists, while ovipositing required a large enclosure to allow the caddisflies sufficient space to ‘swarm’ above the water. Pupation times varied from 17 days to more than 20, with most 5th instars beginning their pupal phase by late June. Investigating the timing of the N. albida life cycle and how it coincides with the growth of macrophytes, native and introduced, provides insights into the larger ecosystem of Chatcolet Lake and the interactions between the caddisfly and macrophyte communities.
Comments
T70