Micrasema longulum(Trichoptera: Brachycentridae) builds a special pupation chamber

Abstract

Larvae of the caddisfly suborder Integripalpia normally pupate in the last instar larval tube-case. Measurements of case structures show that larvae of Micrasema longulum differ in adding a long parallel-sided anterior section to their tube-cases, shortly before pupation. They pupate in the newly built section, discarding the slightly conical larval case. Literature data suggest that two additional species of Micrasema exhibit similar behaviour. Production of a special section of tube-case for pupation is reminiscent of the situation in the primitive suborders Annulipalpia and Spicipalpia which build a pupal case which is often the only construction during the entire life cycle. It is uncertain if the behaviour of Micrasema is atavistic, or if it developed independently.Micrasema longulum (Trichoptera : Brachycentridae) construit un fourreau nymphal spécial Mots-clés : Trichoptère, construction de fourrreau, étui, étui nymphal, trait atavistique. Les larves de Trichoptères du sous-ordre des Integripalpia normalement se nymphosent dans le fourreau larvaire. Des mesures montrent que les larves de

Mineral grains in caddisfly pupal cases and streambed sediments: assessing resource use and its limitation across various river types

“…Typically, these case-carrying larvae add material to the case front and cut the case back off after each larval molt, and pupate in the larval case after they have fixed it to coarser material (e.g., a cobble) on the stream bottom (Waringer and Graf, 1997;Malicky, 2000;Wiggins, 2001). Thus, these "Itinerant Construction Workers" (ICWs) acquire the building material for the pupal case distant from the pupation location during their larval life (although a few among the limnephilids and brachycentrids build new cases prior to pupation; Zwick, 1998;Malicky, 2000;Wiggins, 2001). Consequently, ICWs should typically not be limited by the availability of building material near the locations where they fix their pupal cases.…”

Case‐building of some Trichoptera larvae in experimental conditions: Selectivity for calcareous and siliceous grains

“…Since the first study on the case-building behaviour of Glyphotaelius pellucidus, Limnephilus rhombicus, and Sericostoma personatum carried out under experimental conditions by Moretti (1933), various species have been investigated from this perspective, and an increasing number of papers have dealt with the building methods, the mechanisms involved in controlling this activity, and the plasticity and repairing of the cases (Merril, 1965;Marstaller, 1969;Lepneva, 1971;Smart, 1974;Tachet, 1978;Tomaszewski, 1981;Rennerich & Schuhmacher, 1984;Weaver III & Morse, 1986;Houghton & Stewart, 1998;Zwick, 1998;Gupta & Stewart, 2000;Malicky, 2000). A preference of particles for case building was experimentally investigated by Nepomnyaschikh (1992) in the larvae of Chaetopteryx villosa, and it was proved that larvae, which in natural conditions use large, flat detritus particles (Lepneva, 1971), more readily chose egg shells rather than sand from a mixture.…”