The Gyrinidae (Coleoptera) of the Maritime Provinces of Canada: new records, distribution, and faunal composition

Abstract

Th e Gyrinidae (whirligig beetles) of the Maritime Provinces of Canada are surveyed. Twenty-two species are now known to occur in the region, 19 of which have been recorded from Nova Scotia, 17 from New Brunswick, and 9 from Prince Edward Island. Seven species are newly recorded in Nova Scotia, and four in New Brunswick. Two of these, Gyrinus dichrous LeConte and Gyrinus gehringi Chamberlain, are newly recorded in the Maritime Provinces. Th e zoogeographic composition of the fauna within the region is briefl y examined, the species falling into six categories. Islands portions of Atlantic Canada (Prince Edward Island, Cape Breton, and insular Newfoundland) have a diminished fauna, roughly 40% that of neighbouring mainland areas. Th e proportionate composition of the gyrinid fauna in various portions of Atlantic Canada is similar to that of the Carabidae (a much larger suite of beetles that have been more extensively investigated) with the exception of New Brunswick, where a diminished number of recorded gyrinids would appear to indicate an insuffi cient collecting eff ort for this family in the province. Finally, a preliminary examination of multispecies associations is presented which indicates that some species more frequently engage in such aggregations than others.

New Coleoptera records from New Brunswick, Canada: Gyrinidae, Carabidae, and Dytiscidae

“…Larvae are predaceous on aquatic insect larvae and nymphs ( Oygur and Wolfe 1991 ; Roughley 2001 ). Majka and Kenner (2009) reviewed the gyrinid fauna of the Maritime provinces of Canada and reported 17 species from New Brunswick, including four species newly reported for the province. Recent survey work by the first author has resulted in the discovery of two additional species from New Brunswick.…”

“…Recent survey work by the first author has resulted in the discovery of two additional species from New Brunswick. See Majka and Kenner (2009) for a list of the other species occurring in the province.…”

“…This paper treats new species records from New Brunswick, Canada of the Coleoptera families Gyrinidae , Carabidae , and Dytiscidae . The fauna of these families from New Brunswick and the Maritime provinces was recently treated by Majka and Kenner (2009) ( Gyrinidae ), Webster and Bousquet (2008) ( Carabidae ), and Webster (2008) ( Dytiscidae ). Intensive sampling in New Brunswick by the first author has yielded ad ditional new provincial records in the above families.…”

Deadwood and saproxylic beetle diversity in naturally disturbed and managed spruce forests in Nova Scotia

“…Majka (2007) examined 14 families, subfamilies, and tribes of saproxylic beetles in the Maritime Provinces of Canada and found 59 apparently rare species (representing ≤ 0.005% of specimens from the region) that comprise 33% of the 178 species within these groups. Majka (2007) proposed that this apparent scarcity of a large proportion of the saproxylic fauna might be due to the history of forest management practices in the region. If Nova Scotia has not yet suff ered biodepletion to the extent of European forests, this may only refl ect the fact that not enough time has passed for the deadwood lingering from old-forests in second-growth forests to fully return to soil.…”

Observations on the Cave-Associated Beetles (Coleoptera) of Nova Scotia, Canada

“…Geographical distribution and occurrence: a widely distributed Nearctic species (in Canada from British Columbia to Nova Scotia) (Majka & Sörensson, 2007).…”