|Kehl, S: Thremma gallicum McLachlan, 1880: Zur Biologie, Ökologie und Verbreitung einer faunistischen Besonderheit Deutschlands, Entomologie heute, 17, 13-26 (2005)|
Thremma gallicum is an interesting species of the German caddisfly fauna because of its unique case form and its restricted distribution in the northern Black Forest. Several new records for this species are described here. Chloride epithelia could be identified for T. gallicum at the 5th abdominal sternite of the 2nd to 5th instar. The function of abdominal chloride epithelia is the absorption of ions. These epithelia are known from larvae of Limnephilidae and Goeridae and were so far unknown for Thremmatinae. The width of the head capsule and other measured lengths help to determine the larval stages. The sampling dates and larval instars provide information on the phenology of the species. The first pupae were found in early to mid May, the flight period starts in June. The larvae of T. gallicum are typical grazers and mostly contained diatoms of the genus Diatoma in their foreguts.