Aquatic Herbivores, Detritivores, and Predators

Not only do many aquatic insects serve as food for fish, they play major roles in nutrient cycling, feeding on primary producers, converting organic matter to higher trophic levels. The aquatic insects listed as sensitive are dependent on a limited range of physical conditions for suitable habitat and their sensitivity to forest management practices is least as great as that of the soil and litter dwelling species.

There are aquatic species adapted to all segments of streams and rivers ranging from small headwater springs and seeps, waterfalls, small streams, to larger, slow-flowing rivers.

Examples of headwaters species include the nymphs of the primitive dragonfly Tanypteryx hageni live in spring-fed bogs or seeps in old-growth or riparian forest (Meyer and Clement, 1978; Clement and Meyer, 1980), while nymphs of the spring stonefly Ostrocerca dimicki live in spring-fed rivulets that lead into small, meandering streams (Young et al., 1989). Several other stoneflies of the genus Soliperla have nymphs that are found only in seeps in the headwaters of small streams (Stark, 1983). These springs and seeps are very sensitive to activities such as the construction of roads, ditches, or rights- of-way that might interfere with their flow. Similarly, other logging or construction activities must be planned so that the thermal regimes or flows of these habitats is not interfered with.

Other aquatic species are dependent on cool clear, flowing rivers with sandy, gravelly, or rocky substrates. Two dobsonflies (Dysmicohermes dijunctus and Orohermes crepusculus) rely on cold, clear, fast-flowing streams with unsilted bottoms (Chandler, 19xx). The mountain midge (Deuterophlebia shasta) is found in only three clear, cool streams in northwesterm California and southwestern Oregon (Courtney, 1989).

Two crustaceans on the U.S. List of Endangered Species (USDI, 1988a, 1988b) have stream habitats within the range of the northern spotted owl. The Shasta crayfish (Pacifastacus fortis) is endemic to several rivers in Shasta County, California, where it is principally threatened by introduction of crayfish from other regions. The Shasta crayfish also relies on the presence of cool, clear water in its stream habitats (Bouchard, 1977; Erman, 1993). The California freshwater shrimp (Syncaris pacifica) dwells in low gradient streams in Marin, Napa, and Sonoma counties, California, where it relies on relatively clear streams with sandy and gravelly bottoms, although some mud, silt, and organic debris is tolerated (Eng, 1981; Serpa, 1991). Suitable stream habitats are almost completely shaded by overarching tree canopies. The habitats of both species are downstream from northern spotted owl habitats and conceivably could be affected by stream siltation or changed flows from any changes in forestry management practices upstream.

A number of caddisflies within the range of the northern spotted owl are considered candidates for listing under protection of the U.S. Endangered Species Act (USDI, 199x), and most of these rely on cool, clear streams with unsilted bottom conditions.

Class Crustacea (crustaceans) (Malacostraca)

Order Decapoda (shrimp and crayfish)

Family Astacidae

Pacifastacus fortis (Faxon), Shasta Crayfish

Syncaris pacifica (Holmes), California freshwater shrimp

Class Insecta (insects)

Order Ephemeroptera (mayflies)

Family Ephemerellidae

Drunella doddsi (Needham)

Ephemerella infrequens McDunnough

Order Odonata (damselflies and dragonflies)

    Suborder Anisoptera (dragonflies)

Family Petaluridae (graybacks)

Tanypteryx hageni (Selys)

Family Gomphidae (clubtails)

Octogomphus specularis Hagen

Order Plecoptera (stoneflies)

Family Nemouridae (spring stoneflies)

Ostrocerca dimicki (Frison)

Ostrocerca foersteri (Ricker)

Nemoura (Zapada) wahkeena Jewett, Wahkeena Falls flightless stonefly

Family Capniidae (small winter stoneflies)

Paracapnia oswegaptera (Jewett)

Family Leuctridae (rolled-winged stoneflies)

Paraleuctra andersoni Harper and Wildman

Family Peltoperlidae

Soliperla fenderi (Jewett), Fender's soliperlan stonefly

Soliperla campanula (Jewett)

Soliperla quadrispinula (Jewett)

Soliperla thyra (Needham and Smith)

Soliperla tilamook Stark

Order Megaloptera (dobsonflies, fishflies, and alderflies)

Family Corydalidae (dobson flies)

Dysmicohermes disjunctus (Walker)

Orohermes crepusculus (Chandler)

Order Coleoptera (beetles)

Family Psephenidae (water-penny beetles)

Acneus beeri, Beer's false water penny (beetle)

Acneus burnelli, Burnell's false water penny (beetle)

Family Hydrophilidae

Chaetarthria leechi, Leech's chaetarthria water scavenger beetle

Order Trichoptera (caddisflies)

Family Philopotamidae (finger-net caddisflies)

Dolophilodes novusamerica (Ling)

Family Rhyacophilidae (primitive caddisflies)

Himalopsyche phryganea (Ross)

Rhyacophila amabilis Denning

Rhyacophila colonus Schmid, O'Brien rhyacophila caddisfly

Rhyacophila fenderi Ross, Fender's rhyacophilan caddisfly

Rhyacophila haddocki Denning, Haddock's rhyacophilan caddisfly

Rhyacophila lineata Denning, Castle Crags rhyacophilan caddisfly

Rhyacophila mosana Denning, Bilobed rhyacophilan caddisfly

Rhyacophila willametta Ross

Family Phryganeidae (large caddisflies)

Yphria californica (Banks)

Family Uenoidae (northern caddisflies)

Apatania sorex (Ross)

Farula jewetti Denning, Mt. Hood farulan caddisfly

Neothremma andersoni Wiggins, Columbia Gorge neothremman caddisfly

Neothremma siskiyou Denning

Oligophlebodes sierra Ross

Family Psychomyiidae (trumpet-net caddisflies)

Tinodes siskiyou Denning, Siskiyou caddisfly

Family Hydropsychidae (net-spinning caddisflies)

Homoplectra alsea Ross

Homoplectra schuhi Denning, Schuh's homoplectran caddisfly

Abellan hydropsyche

Family Lepidostomatidae (lepidostomatids)

Lepidostoma cascadense (Milne)

Family Brachycentridae (brachycentrids)

Eobrachycentrus gelidae Wiggins, Mt. Hood primitive brachycentrid caddisfly

Family Goeridae

Goera archaon Ross

Family Hydroptilidae

Ochrotrichia vertreesi Denning and Blickle, Vertrees' ochroctrichian micro caddisfly

Family Limnephilidae

Apatania tavala (Denning), Cascades apatanian caddisfly

Cryptochia shasta Denning, Confusion caddisfly

Desmona bethula Denning, Amphibious caddisfly

Philocasca demita Ross

Philocasca oron Ross, Clatsop philocascan caddisfly

Order Diptera (true flies)

    Suborder Nematocera (primitive flies)

Family Psychodidae (moth flies)

Maurina sp.

Family Simuliidae (black flies)

Parasimulium undescribed species

Family Deuterophlebiidae (mountain midges)

Deuterophlebia shasta Wirth


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