Canadian Journal of Arthropod Identification

Cleptoparasitic Bees of the Genus Epeolus Latreille (Hymenoptera: Apidae) in Canada

CJAI 30 -- March 30, 2017

Thomas M. Onuferko

| Abstract | Introduction | Methods | Taxonomy & Biology | Checklist | Keys to species | Acknowledgments | References | PDF | Cite |


A high proportion (28%) of bees in the family Apidae (Hymenoptera: Apoidea) are cleptoparasites of nest-building bees (Cardinal et al. 2010). Cleptoparasitic (or cuckoo) bees appropriate the pollen food stores collected by females of their host species for their own offspring; the cleptoparasite invades the host nest and lays an egg in the brood cell. Subsequently, the host larva or egg (depending on the type of cleptoparasitic bee involved) is killed. Since female cleptoparasitic bees do not collect pollen to feed their brood, they lack the specialized pollen-carrying scopae characteristic of most nest-building bees. Most cleptoparasites are also wasp-like in appearance, exhibiting reduced hairiness, and typically have black and yellow and/or red colouration.
            In the Nearctic region, the cleptoparasitic tribe Epeolini (Subfamily Nomadinae) is represented by Epeolus Latreille, Odyneropsis Schrottky (Griswold and Parker 1999), and Triepeolus Robertson (Robertson 1901). Of these, only Epeolus and Triepeolus occur in Canada, and they are the two most diverse genera in the entire tribe (Rightmyer 2004).

            To date, no key to all the Canadian species has been published, although a key to the Epeolini of Ontario, the province with the greatest Epeolus diversity, exists (Romankova 2004). I have seen specimens from all provinces and territories in Canada except Newfoundland and Labrador and Nunavut (Map 14). I have verified locality records for 12 species in Canada (Table 1), but the key provided herein includes a thirteenth (E. ilicis Mitchell), which may occur in southern Ontario, whose Canadian voucher specimens (Romankova 2004) cannot be traced. The purpose of the present study is thus to provide a key to all species that might occur in Canada, and to redescribe them.

Table 1. Epeolus in Canada and associated Colletes host species. The nature of the evidence for all confirmed, hypothesized (based on personal assessment), or presumed (suspected and published) associations is indicated in the Discussion section of the taxonomic treatment of each species. Unless otherwise stated, confirmed associations are based on evidence of oviposition by female Epeolus within a Colletes nest, and hypothesized and presumed associations are based on spatial and temporal co-occurrence.

Cleptoparasite species Associated host species Reference(s)
E. ainsliei C. americanus Cresson and/or C. susannae Swenk (presumed) Wolf and Ascher (2009)
E. americanus C. consors mesocopus Swenk (hypothesized based on shared habitat in Alaska and flight season, although at least three other Alaskan Colletes spp. are known) Armbruster and Guinn (1989)
E. autumnalis C. compactus compactus Cresson (presumed) Ascher et al. (2014)
E. bifasciatus C. latitarsis Robertson (presumed) Mitchell (1962)
E. canadensis Possibly C. kincaidii Cockerell (hypothesized) MacKay and Knerer (1979)
E. compactus C. kincaidii Cockerell (confirmed) Torchio and Burdick (1988)
E. ilicis C. brimleyi Mitchell (confirmed) Rozen (1989)
E. interruptus C. aestivalis Patton (presumed for unclear reasons) Brumley (1965)
E. lectoides C. latitarsis Robertson and C. nudus Robertson (presumed) Shapiro and Droege (2010) Ascher et al. (2014)
E. minimus C. eulophi Robertson (presumed based on female Epeolus entering Colletes nest) Graenicher (1906)
E. pusillus C. ciliatoides Stephen and C. compactus compactus Cresson (confirmed) Torchio (1965) Rozen and Favreau (1968)
E. scutellaris C. simulans armatus Patton (presumed) Ascher et al. (2014)
E. olympiellus C. hyalinus Provancher (hypothesized based on co-occurrence) pers. comm. Cory Sheffield