Patrobus longicornis (Say) 1823  

Found in a variety of habitats; under stones near mouth of Rock Run, in leaf litter at edge of Pond, and according to Lindroth (1961b) "On meadows, in light deciduous forest, and on cultivated ground with rich vegetation. Usually on clayish soil. Often near margin of lakes and rivers but not really hygrophilous." Both short-winged and fully-winged specimens are found on the Island; the long-winged ones probably fly. These beetles were observed running during the day (Larochelle, 1975a) in Quebec. Several examples were collected on the Island and adjacent Maryland shore between 1903 and the present (HSB, WLM, WVW, TLE & DRW, GGP, TLE & HF). Teneral specimens were found in June and on the Island and in May in the District of Columbia. Mating occurs in June in Quebec (Larochelle, 1972e). Adults were collected in April, May, June, October, and November. Hibernation probably takes place both in the larval and adult stages. Total length, 9.2 to 14.8 mm (12.0).

Synonyms: Feronia longicornis, Say,1823; Patrobus americanus, Dejean, 1828