Acari of Canada

Abstract

Summaries of taxonomic knowledge are provided for all acarine groups in Canada, accompanied by references to relevant publications, changes in classification at the family level since 1979, and notes on biology relevant to estimating their diversity. Nearly 3000 described species from 269 families are recorded in the country, representing a 56% increase from the 1917 species reported by Lindquist et al. (1979). An additional 42 families are known from Canada only from material identified to family- or genus-level. Of the total 311 families known in Canada, 69 are newly recorded since 1979, excluding apparent new records due solely to classification changes. This substantial progress is most evident in Oribatida and Hydrachnidia, for which many regional checklists and family-level revisions have been published. Except for recent taxonomic leaps in a few other groups, particularly of symbiotic mites (Astigmata: feather mites; Mesostigmata: Rhinonyssidae), knowledge remains limited for most other taxa, for which most species records are unpublished and may require verification. Taxonomic revisions are greatly needed for a large majority of families in Canada. Based in part on species recorded in adjacent areas of the USA and on hosts known to be present here, we conservatively estimate that nearly 10,000 species of mites occur in Canada, but the actual number could be 15,000 or more. This means that at least 70% of Canada’s mite fauna is yet unrecorded. Much work also remains to match existing molecular data with species names, as less than 10% of the ~7500 Barcode Index Numbers for Canadian mites in the Barcode of Life Database are associated with named species. Understudied hosts and terrestrial and aquatic habitats require investigation across Canada to uncover new species and to clarify geographic and ecological distributions of known species.

DNA barcodes expose unexpected diversity in Canadian mites

“…BIN summary by order, with extrapolated BIN richness using the incidence coverage estimator (ICE) in comparison with known and expected species counts for mites in Canada (Beaulieu et al, ) [Colour figure can be viewed at wileyonlinelibrary.com]…”

“…At least one BIN was recorded for 186 (60%) of the 311 mite families known from Canada (Beaulieu et al, ). Average BIN richness did not differ significantly from the expected species richness for each family (mean BIN richness = 37.9, mean expected species = 43.4; paired t test, p < .1), but the ratios showed marked variation (1–16×).…”

“…The observed and estimated BIN richness values for each order were compared with expected species richness following the taxonomy used by Beaulieu et al () with two exceptions. Beaulieu et al () placed the Eriophyoidea within the Endeostigmata (Sarcoptiformes) following Klimov et al (), while we retained the conventional placement of this superfamily within the Trombidiformes (Krantz & Walter, ). Secondly, we retained the Eutromibidiidae as a distinct family (C. Welbourn, personal communication) while Beaulieu et al () merged it with the Mircrotrombidiidae.…”

“…Beaulieu et al () placed the Eriophyoidea within the Endeostigmata (Sarcoptiformes) following Klimov et al (), while we retained the conventional placement of this superfamily within the Trombidiformes (Krantz & Walter, ). Secondly, we retained the Eutromibidiidae as a distinct family (C. Welbourn, personal communication) while Beaulieu et al () merged it with the Mircrotrombidiidae. The observed BIN richness and expected species richness values from Beaulieu et al () were compared for each family using a paired t test.…”

“…Secondly, we retained the Eutromibidiidae as a distinct family (C. Welbourn, personal communication) while Beaulieu et al () merged it with the Mircrotrombidiidae. The observed BIN richness and expected species richness values from Beaulieu et al () were compared for each family using a paired t test.…”