Notes on Bryothinusa With Description of the Larva of B. Catalinae Casey (Coleoptera: Staphylinidae)

A number of insects are restricted to special marine habitats along the California seashore. At least one of these habitats is intertidal in the sense that its fauna is regularly submerged by the tides. This is the fauna of the reefs. Several species of staphylinids are known from this region. Members of the staphylinid genera Liparocephalus, Amblopusa and Diaulota are found on the rocky shores of northern California; while in southern California only members of the genera Diaulota and Bryothinusa are known. Several studies have dealt with these insects including Chamberlain and Ferris (1929) and Moore (1956a, 1956b). Larvae of some of the species have been described. The larva of Bryothinusa catalinae Casey is described and illustrated for the first time in this paper. Bryothinusa catalinae (Fig. I), the type species of the genus, was described by Casey in 1904. Sawada (1955, 1971) described four species from Japan under the name Halaesthenus. Several species were described from the harbor at Hong Kong by Moore and Legner (1971) and Moore, Legner and Chan (1973). Finally, another species was made known by Moore and Legner (1975) from the Gulf of California, bringing the total number of known species to eleven. All but one of these is restricted to an intertidal habitat; the exception being B.fluenta Moore et al. which was found by TaiDin Chan in a strictly fresh water habitat in a stream emptying into Hong Kong harbor. Bryothinusa catalinae is not common in collections probably because of its restricted habitat. Derharn Giuliani collected ten adult specimens of this species incidental to other work in October, 1976, near White Point, San Pedro, California, and presented the specimens to us. We made two trips to the area in November and December, 1977, where we found both adults and larvae fairly common. This special habitat may be described as follows: