Bionomics of Dicosmoecus gilvipes (Trichoptera: Limnephilidae) in a large western Montana River

Journal Article · Thu Jul 01 00:00:00 EDT 1982 · Am. Midl. Nat.; (United States)

DOI:https://doi.org/10.2307/2425295· OSTI ID:6329952

Hauer, F R ^[1]; Stanford, J A

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1. Univ. of Montana, Bigfork

Dicosmoecus gilvipes (Hagen) has a 2-year life cycle in the upper Flathead River, Montana. First-instar larvae appeared in spring and grew to fourth instar by late summer. Larvae typically entered fifth instar during late summer or autumn and spent the winter months attached to the undersides of large rocks in apparent diapause. Fifth-instar larvae were again active as water temperatures warmed above 1 C in March. In midsummer, fifth-instar larvae again attached their cases to the undersides of rocks and entered a 4- to 6-week prepupal diapause prior to metamorphosis. Adults emerged from late August through October. Early-instar larvae occurred primarily in depositional areas at the edge of riffles or in pools and backwater areas. Late-instar larvae were most frequently observed on and within the rubble substrate of lotic erosional zones, yet outside turbulent riffles. The change in habitat from depositional to erosional zones was coincident with decreased river discharge. The 2-year life cycle is explained in terms of temperature and food quantity-quality relationships.

• DOE Contract Number: AC09-76SR00819
• OSTI ID: 6329952
• Journal Information: Am. Midl. Nat.; (United States), Journal Name: Am. Midl. Nat.; (United States) Vol. 108:1; ISSN AMNAA
• Country of Publication: United States
• Language: English

Related Subjects

520100* -- Environment
Aquatic-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
ANIMALS
ARTHROPODS
DIPTERA
ECOLOGY
FEDERAL REGION VIII
FLIES
HABITAT
INSECTS
INVERTEBRATES
LARVAE
LIFE CYCLE
METAMORPHOSIS
MONTANA
NORTH AMERICA
RIVERS
SEASONAL VARIATIONS
STREAMS
SURFACE WATERS
TEMPERATURE DEPENDENCE
USA
VARIATIONS