Glossosoma nigrior

Distinguished from other Glossosoma species by geographic distribution and specific habitat associations. Larval cases are constructed from small mineral particles bound with silk, characteristic of the family Glossosomatidae. Adults are small and black in coloration.

Small black caddisfly. Larvae construct portable cases typical of Glossosomatidae, using silk and small stones or sand particles.

Freshwater lotic systems, specifically streams and rivers. In Michigan, occurs in trout streams as the dominant benthic invertebrate. In Alabama, found in both sandstone-underlain streams (Appalachian Plateau) and limestone-underlain streams (Valley and Ridge physiographic province). Prefers streams with stable hydrology, optimal habitat availability, and warmer winter water temperatures.

North America. Documented from Michigan, Alabama, and Vermont in the United States. Occurs in the Nearctic region.

Adults active during warmer months. In Alabama, exhibits continuous larval growth throughout the year due to favorable thermal conditions.

Algae (>50%) and detritus (>40%). Functions as a scraper, grazing on periphyton and organic material from submerged surfaces.

• Cougourdella sp. - microsporidian parasite/pathogenStrongly regulates larval population density. Both sexes of adults can be infected with mature environmental spores, but spores are not associated with reproductive tissue. Oral and transovum transmission routes do not appear to occur.

Trivoltine (three generations per year) in warmer southern streams, attributed to higher water temperature regimes than northern populations. Larval stage aquatic and benthic; adult stage terrestrial but returns to streams. Larvae construct portable cases and maintain continuous growth in optimal habitat conditions.

Larvae exhibit behavioral responses to fluid flow conditions affecting oxygen delivery. At low Peclet numbers (Pe < 87), larvae occasionally abandon cases or spend more time partially extended from cases due to insufficient oxygen delivery. At higher flow velocities (Pe > 87), larvae typically remain within cases. Larvae increase oxygen uptake rates in response to increased fluid flow velocity.

Dominant benthic invertebrate grazer in Michigan trout streams and important contributor to secondary production in Alabama streams. Contributes >80% of secondary production through algae consumption in some systems. Functions as a key trophic linkage between primary producers and higher consumers in stream food webs.

Serves as a bioindicator species for stream health and water quality. Used in ecological studies of stream metabolism and secondary production. Population dynamics are studied as a model for understanding pathogen regulation of invertebrate populations.

• Other Glossosoma speciesShare similar case-building behavior and habitat preferences; distinguished by geographic range and specific stream associations
• Other Glossosomatidae generaSimilar case morphology using silk-bound mineral particles; distinguished by case architecture and larval morphology

• caddisfly
• aquatic insect
• benthic grazer
• stream ecology
• bioindicator

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Life history and secondary production of Glossosoma nigrior Banks (Trichoptera: Glossosomatidae) in two Alabama streams with different geology
• Studies on the Life Cycle and Transmission of <i>Cougourdella</i> Sp., A Microsporidian Parasite of <i>Glossosoma Nigrior</i> (Trichoptera: Glossosomatidae)
• Glossossoma nigrior (Trichoptera: Glossosomatidae) respiration in moving fluid