Biology and immature stages of Ochrotrichia quadrispina Denning and Blickle (Trichoptera : Hydroptilidae), a spring-inhabiting scraper

Larvae of Ochrotrichia quadrispina Denning and Blickle were obtained from a spring adjacent to the high tide line of a southern California beach. The spring created a madicole over exposed bedrock within which larvae grazed p eriphyton. Although the filamentous chlorophyte Clacdophora was present, no larvae consumed this alga during observations of all instars in the labora tory. Gut contents analysis showed that unicellular algae, detritus, and mi neral materials were consumed in the field. Final instars constructed cases of a single convex dome with a flexible silken ventral valve that sealed t he case when larvae were withdrawn. Morphological descriptions of the five instars are given.