Systematics and biology for a new Nearctic genus in the caddisfly family Phryganeidae (Trichoptera)

• Published in: Canadian Journal of Zoology
• Main Authors: Wiggins, Glenn B., Larson, David J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1989
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Newfoundland
• Online Access: http://dx.doi.org/10.1139/z89-220; http://www.nrcresearchpress.com/doi/pdf/10.1139/z89-220

Discovery of the larval and pupal stages of the northern North American species Fabria complicata (Banks) reveals that the pupal mandibles are degenerate and that a silken sieve membrane is not constructed across the anterior opening of the case at pupation. Supporting this relationship with the small aberrant group of adecticous genera in the Phryganeidae are several other derived structural characters of larvae (long antennae, mesonotal sclerites) and adults (complex structure of segments IX and X of male genitalia), and of case-making behaviour (discrete rings instead of a continuous spiral). However, because complicata cannot be interpreted as monophyletic with any of these genera, recognition of a new genus, Beothukus, is required. Larvae of the population of B. complicatus studied in Newfoundland were found in small sphagnum bog pools where pH ranged from 4.2 to 4.9, and fed on algae, insects, and crustaceans; the species is univoltine at this site. Beothukus complicatus (Banks) is a noteworthy species because it is one of the few Trichoptera known to live in bog pools of low pH, and because it is another of the exceptions invalidating the widespread perception that all Trichoptera have decticous pupae.