INCORPORATION OF FRESHWATER RHODOPHYTA INTO THE CASES OF CADDISFLIES (TRICHOPTERA) FROM NORTH AMERICA

Cases of larvae and pupae from six caddisfly (Insecta, Trichoptera) genera in three families from North America were observed to contain pieces of freshwater rhodophyte thalli. Seven genera of Rhodophyta, representing 13 species and 35 populations, were observed in this association. Four of the 25 species of Batrachospermum were incorporated into cases of Ochrotrichia ( Hydroptilidae) and Agrypnia ( Phryganeidae). Two of the three freshwater species of Bostrychia were used by Ochrotrichia larvae. Both Compsopogon coeruleus ( Balbis) Mont. and C. prolificus Yadava et Kumano were present in the cases of Hydroptial ( Hydroptilidae) and Ochrotrichia; Compsopogonopsis leptocladus ( Mont.) Krishnamur-thy was observed in the cases of Hydroptila. The more cartilaginous thalli of Lemanea fluviatilis ( L.) C. Ag. and Tuomeya americana ( Kütz.) Papenfuss were used by the brachycentrid larvae of Brachycentrus and Mi-crasema. Lemanea and Paralemanea spp. were also in the cases of Dibusa angata Ross (Hydroptilidae). The architecture of each caddisfly case was studied with light and scanning electron microscopy. Strips of algae were fit together in a transverse, concentric, or spiralled fashion. Based on transmission electron micrographs, cortical cells of Lemanea and Tuomeya in the cases of Brachycentrus and Micrasema appeared to be healthy with intact chloroplasts and typical batrachospermalean pit plugs. Geographic distributions of each rhodophyte-caddisfly association are given .