The 23 species of Haliplidae (crawling water beetles) now known from eastern Canada are reviewed and keyed. H. falli Mank is recorded from Ontario for the first time, H. canadensis Wallis and H. fasciatus Aubé are recorded from New Brunswick for the first time, and H. connexus Matheson is recorded from Prince Edward Island for the first time. The recently described species Haliplus lucigelinae Vondel and Alarie is included in a key for the first time.

Brychius hungerfordi Spangler (photo by S.A. Marshall)

The family Haliplidae (crawling water beetles) is a primarily Holarctic family of small (~2-5 mm) water beetles easily recognized by their greatly enlarged hind coxal plates. Most species occur in lentic habitats rich in the algae on which they develop, although a few species are found in slow moving water, and the endangered Hungerford’s Crawling Water Beetle (Brychius hungerfordi Spangler) is found in swift rocky streams.

Up until now, the only key to the northeastern species of Haliplidae was in Downie and Arnett (1996), a poorly illustrated key lacking two of the species now known in eastern Canada and containing a number of problematic couplets. We here provide a simpler, more complete and fully illustrated key along with a review of the eastern Canadian species updating the composition and distribution of the fauna. One of species, Hungerford’s Crawling Water Beetle (Brychius hungerfordi) is recognized as an endangered species under federal and provincial legislation in Canada and Ontario, and has been listed as endangered in the United States, where it occurs in only five swift, clean streams in Michigan, since 1994. Although Hungerford’s Crawling Water Beetle has received a great deal of attention and resources, little attention has been paid to the other Haliplidae. One of the incentives for starting this project was the assumption that other Haliplidae had been neglected because there were no accessible user-friendly tools for identification of species other than the easily recognized B. hungerfordi. But, as can be seen from the distribution maps provided here, several species (e.g., Peltodytes lengi Roberts, P. litoralis Matheson, Haliplus apostolicus Wallis, H. leopardus Roberts and H. lucigelinae Vondel and Alarie) have very restricted distributions and are infrequently collected. The baseline distributional data and simple identification tools provided here will hopefully encourage further study of these species.

Specimen data were obtained from the University of Guelph Insect Collection (DEBU, Guelph, Canada), the Canadian National Collection of Insects, Arachnids and Nematodes (CNC, Ottawa, Canada), the Royal Ontario Museum (ROM, Toronto, Ontario, Canada), the Wallis-Roughley Museum (JBWM, University of Manitoba, Winnipeg, Canada), and the personal database of Yves Alarie (Laurentian University, Sudbury, Canada).

Distribution maps were created using Simplemappr (Shorthouse, 2010). They include both broad provincial distributions (demarcated by diagonal lines) and specific localities (demarcated by dots). Provincial distributions were obtained from Bousquet (1991), Downie and Arnett (1996), Majka et al. (2009) and Vondel (2013), while specific localities were obtained from specimen data labels and published literature (LeConte, 1950; Vondel, 2005; Majka et al., 2009). In some cases only provincial records were available, mostly from Downie and Arnett (1996) and Vondel (2013).

Table 1. Checklist of Haliplidae of eastern Canada. ON, Ontario; QC, Quebec; NB, New Brunswick; NS, Nova Scotia; PE, Prince Edward Island; LB, Labrador; NF, Newfoundland.

Dorsal Morphology

Ventral Morphology

Male Reproductive Structures