2011
Limm, Michael P.; Power, Mary E.
The caddisfly Dicosmoecus gilvipes: making a case for a functional role Journal Article
In: Journal of the North American Benthological Society, vol. 30, no. 2, pp. 485-492, 2011.
Abstract | Links | BibTeX | Tags: camouflage, case, Dicosmoecus, drag, function, predation, stability, Trichoptera
@article{Limm2011b,
title = {The caddisfly Dicosmoecus gilvipes: making a case for a functional role},
author = {Michael P. Limm and Mary E. Power},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Limm_2011_JNAmBentholSoc.pdf},
doi = {10.1899/10-028.1},
year = {2011},
date = {2011-03-29},
journal = {Journal of the North American Benthological Society},
volume = {30},
number = {2},
pages = {485-492},
abstract = {Most caddisfly larvae build cases of silk and a variety of collected materials. Multiple functions,
including protection from predators, resistance to entrainment by high flows, and improved respiration,
have been suggested for caddisfly cases. We investigated the functional role of cases built by Dicosmoecus gilvipes, a limnephilid caddisfly. In this species, the 1st- through 4th-instar larvae build cases with plant material and attach Douglas-fir needles as lateral extensions that resemble vanes on an arrow. We tested whether the lateral extensions and entire case deterred predators by manipulating lateral extensions and case presence for larvae exposed to large steelhead trout. No larva with a case (with or without lateral extensions) was consumed during the experiment, whereas all larvae without a case were consumed. We tested whether lateral extensions provided stability against overturning and entrainment by manipulating presence of lateral extensions and subjecting larvae to turbulent flow conditions. Once dislodged, larvae with lateral extensions experienced fewer revolutions and regained their footing faster than those without extensions. Our results suggest lateral extensions provide stability against overturning in fast flow and may improve the ability of larvae to forage efficiently in turbulent flow conditions. Other caddisfly species build lateral extensions on their case, and the extensions may provide similar benefits for these taxa.},
keywords = {camouflage, case, Dicosmoecus, drag, function, predation, stability, Trichoptera},
pubstate = {published},
tppubtype = {article}
}
Most caddisfly larvae build cases of silk and a variety of collected materials. Multiple functions,
including protection from predators, resistance to entrainment by high flows, and improved respiration,
have been suggested for caddisfly cases. We investigated the functional role of cases built by Dicosmoecus gilvipes, a limnephilid caddisfly. In this species, the 1st- through 4th-instar larvae build cases with plant material and attach Douglas-fir needles as lateral extensions that resemble vanes on an arrow. We tested whether the lateral extensions and entire case deterred predators by manipulating lateral extensions and case presence for larvae exposed to large steelhead trout. No larva with a case (with or without lateral extensions) was consumed during the experiment, whereas all larvae without a case were consumed. We tested whether lateral extensions provided stability against overturning and entrainment by manipulating presence of lateral extensions and subjecting larvae to turbulent flow conditions. Once dislodged, larvae with lateral extensions experienced fewer revolutions and regained their footing faster than those without extensions. Our results suggest lateral extensions provide stability against overturning in fast flow and may improve the ability of larvae to forage efficiently in turbulent flow conditions. Other caddisfly species build lateral extensions on their case, and the extensions may provide similar benefits for these taxa.
including protection from predators, resistance to entrainment by high flows, and improved respiration,
have been suggested for caddisfly cases. We investigated the functional role of cases built by Dicosmoecus gilvipes, a limnephilid caddisfly. In this species, the 1st- through 4th-instar larvae build cases with plant material and attach Douglas-fir needles as lateral extensions that resemble vanes on an arrow. We tested whether the lateral extensions and entire case deterred predators by manipulating lateral extensions and case presence for larvae exposed to large steelhead trout. No larva with a case (with or without lateral extensions) was consumed during the experiment, whereas all larvae without a case were consumed. We tested whether lateral extensions provided stability against overturning and entrainment by manipulating presence of lateral extensions and subjecting larvae to turbulent flow conditions. Once dislodged, larvae with lateral extensions experienced fewer revolutions and regained their footing faster than those without extensions. Our results suggest lateral extensions provide stability against overturning in fast flow and may improve the ability of larvae to forage efficiently in turbulent flow conditions. Other caddisfly species build lateral extensions on their case, and the extensions may provide similar benefits for these taxa.
1994
Bergey, E. A.; Resh, V. H.
Effects of burrowing by a stream caddisfly on case-associated algae Journal Article
In: Journal of the North American Benthological Society, vol. 13, no. 3, pp. 379-390, 1994.
Abstract | Links | BibTeX | Tags: burrowing, caddisflies cases, diatoms, diel periodicity, Gumaga, rifigia, streams, Trichoptera
@article{Bergey1994,
title = {Effects of burrowing by a stream caddisfly on case-associated algae},
author = {E. A. Bergey and V. H. Resh},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Bergey_1994_JorBenthSoc.pdf},
doi = {10.2307/1467367},
year = {1994},
date = {1994-09-00},
journal = {Journal of the North American Benthological Society},
volume = {13},
number = {3},
pages = {379-390},
abstract = {Diel burrowing behavior of Gumaga nigricula (McL.) (Trichoptera:Sericostomatidae) was investigated in Big Sulphur Creek (Sonoma Co., California). Most of the population burrows during the day and surfaces at night, a behavior that facilitates feeding on periphyton while retaining many of the advantages of burrowing (e.g., protection from predators). Because of daytime burrowing, case algae (primarily diatoms) are potentially light-limited by overlying substrate and, indeed, chlorophyll a concentrations on stream-collected cases and diatom colonization on cleaned cases increased dramatically when daytime burrowing was prevented. Cases and case-associated algae are normally abraded during burrowing; therefore experimental abrasion had little effect. However, after cases were cultured to accrue algae, experimental abrasion drastically reduced the accrued algae. Blue-green algal filaments and diatoms were removed from exposed surfaces but were protected in crevices between sand grains. Comparison of cases of different caddisfly genera showed a trend between abrasion level and case-associated algae. Under low abrasion, grazer-resistant diatoms occurred on exposed surfaces and upright diatoms occurred in crevices (e.g., Glossosoma and Discosmoecus cases). As abrasion increased, diatoms were lost from exposed surfaces, although they remained in crevices (e.g., Gumaga cases); with continuous burrowing, cases were nearly devoid of algae (e.g., Agarodes cases)},
keywords = {burrowing, caddisflies cases, diatoms, diel periodicity, Gumaga, rifigia, streams, Trichoptera},
pubstate = {published},
tppubtype = {article}
}
Diel burrowing behavior of Gumaga nigricula (McL.) (Trichoptera:Sericostomatidae) was investigated in Big Sulphur Creek (Sonoma Co., California). Most of the population burrows during the day and surfaces at night, a behavior that facilitates feeding on periphyton while retaining many of the advantages of burrowing (e.g., protection from predators). Because of daytime burrowing, case algae (primarily diatoms) are potentially light-limited by overlying substrate and, indeed, chlorophyll a concentrations on stream-collected cases and diatom colonization on cleaned cases increased dramatically when daytime burrowing was prevented. Cases and case-associated algae are normally abraded during burrowing; therefore experimental abrasion had little effect. However, after cases were cultured to accrue algae, experimental abrasion drastically reduced the accrued algae. Blue-green algal filaments and diatoms were removed from exposed surfaces but were protected in crevices between sand grains. Comparison of cases of different caddisfly genera showed a trend between abrasion level and case-associated algae. Under low abrasion, grazer-resistant diatoms occurred on exposed surfaces and upright diatoms occurred in crevices (e.g., Glossosoma and Discosmoecus cases). As abrasion increased, diatoms were lost from exposed surfaces, although they remained in crevices (e.g., Gumaga cases); with continuous burrowing, cases were nearly devoid of algae (e.g., Agarodes cases)