A first comprehensive synopsis of all aleocharine rove beetle species (Coleoptera, Staphylinidae) recorded from eastern Canada, from Ontario to the Maritime Provinces inclusively, is presented. Four hundred and seven species in 96 genera, and 16 tribes are presented and discussed.Tribes and subtribes are arranged in presumably phylogenetic order as it is currently recognized. Genera and subgenera are listed alphabetically. Species are listed alphabetically or in species groups to better reflect their relationships. Species distribution is listed by abbreviated provinces and territories in Canada and abbreviated states in the United States. Geographic status is given to every species as Native, Holarctic or adventive with some species listed with undetermined status - adventive or Holarctic. Every treated species is presented with a diagnosis, including short description of body and description of the median lobe of aedeagus, spermatheca, and tergite and sternite VIII of both sexes. For each species a plate with colour habitus image and black and white images of genital structures is provided to aid with positive identification. Collection and habitat data (often new) are presented for each species, including data on macrohabitat, microhabitat, collecting period, and collecting methods.

Arctic and Subarctic North America is particularly affected by climate change, where average temperatures are rising three times faster than the global average. Documenting the changing climate/environment of the north requires a structured knowledge of indicator taxa that reflect the effects of climate changes.Aleocharine beetles are a dominant group of forest insects, which are being used in many projects as indicators of environmental change. Many species are forest specialists restricted to certain microhabitats, some are generalists and others are open habitat specialists. They represent many ecological niches and, as such, are good indicators for many other species as well. The majority of Canadian aleocharine beetle species (about 600 spp.) has been studied and published by Jan Klimaszewski et al. (2018, 2020), mainly from southern, central, and western Canada, while the northern taxa remain poorly known and documented. The aim of the present book is to summarize the knowledge on this insect group in the Arctic and Subarctic North America and to provide a diagnostic and ecological tool for scientists studying and monitoring insects in northern Canada and Alaska. The book includes a review of the literature, information on 238 species and their habitats, taxonomic review, images, and identification tools.

Arctic and Subarctic North America is particularly affected by climate change, where average temperatures are rising three times faster than the global average. Documenting the changing climate/environment of the north requires a structured knowledge of indicator taxa that reflect the effects of climate changes.Aleocharine beetles are a dominant group of forest insects, which are being used in many projects as indicators of environmental change. Many species are forest specialists restricted to certain microhabitats, some are generalists and others are open habitat specialists. They represent many ecological niches and, as such, are good indicators for many other species as well. The majority of Canadian aleocharine beetle species (about 600 spp.) has been studied and published by Jan Klimaszewski et al. (2018, 2020), mainly from southern, central, and western Canada, while the northern taxa remain poorly known and documented. The aim of the present book is to summarize the knowledge on this insect group in the Arctic and Subarctic North America and to provide a diagnostic and ecological tool for scientists studying and monitoring insects in northern Canada and Alaska. The book includes a review of the literature, information on 238 species and their habitats, taxonomic review, images, and identification tools.