The Marine Caddisfly Family Chathamiidae (Trichoptera)

The case‐making larvae of the Chathamiidae occur in water of normal oceanic salinity on the rocky sections of the coasts of the south‐western Pacific Ocean. The larval and pupal cases are constructed of algal fragments, usually a finely‐branched calcareous alga on which the larva has been feeding. Two monotypic genera, Philanisus Walker and Chathamia Tillyard, have been included in the family. The family Philanisidae is synonymized with the Chathamiidae. The brachypterous, heavily sclerotized Chathamia brevipennis Tillyard is recorded from the Chatham Islands. Philanisus plebeius Walker is widely distributed in New Zealand and also occurs on the coast of New South Wales, Australia. A new species of Philanisus is described from the Kermadec Islands. A new, fully‐winged species of Chathamia is described from Northland, New Zealand. The characters of the larva of Chathamia have necessitated revision of the family diagnosis based on Philanisus. The pupa of a species of Philanisus is fully illustrated for the first time. The diagnostic characters of the larva, pupa and adult indicate that the Chathamiidae are most closely related to the Leptoceridae. A family key to the pupae of Trichoptera is presented.