SeasonalityAdults fly in spring and early summer (Johnson 2000) and can be collected in Alberta from May througIdentificationLength less than 6.0 mm. Body form narrowly oval, convex, moderately acute anteriorly and posteriorly, black with olive green pubescences (Downie et al. 1996). Antennae and legs markedly stout; sterna with fine, decumbent hairs (bending downward) (El-Moursy 1970). Central transverse mark on elytra with cinereous (grey) spot near centre (El-Moursy 1970). Elytral punctures dense and often coalesced (Johnson 1991). Male genitalia with median lobe narrow at centre and pointed and enlarged at apex; parameres broad at base and narrow near apices (El-Moursy 1970). Female genitalia presently unidentifiable (Hatch 1961). Larvae with large hypognathous head (head and mouth directed ventrally) with discrete ventral epicranial ridges and 6 distinct stemmata. Similar in body form to larvae of Chrysomelidae but with well-developed lacinia and articulated galea (Lawrence 1991).
Scientific NameByrrhus eximiusHabitat
Adults are often found in mosses, moist sand or soil and under logs and stones (El-Moursy 1961).
Seasonality
Adults fly in spring and early summer (Johnson 2000) and can be collected in Alberta from May throug
Identification
Length less than 6.0 mm. Body form narrowly oval, convex, moderately acute anteriorly and posteriorly, black with olive green pubescences (Downie et al. 1996). Antennae and legs markedly stout; sterna with fine,…
Length less than 6.0 mm. Body form narrowly oval, convex, moderately acute anteriorly and posteriorly, black with olive green pubescences (Downie et al. 1996). Antennae and legs markedly stout; sterna with fine, decumbent hairs (bending downward) (El-Moursy 1970). Central transverse mark on elytra with cinereous (grey) spot near centre (El-Moursy 1970). Elytral punctures dense and often coalesced (Johnson 1991). Male genitalia with median lobe narrow at centre and pointed and enlarged at apex; parameres broad at base and narrow near apices (El-Moursy 1970). Female genitalia presently unidentifiable (Hatch 1961). Larvae with large hypognathous head (head and mouth directed ventrally) with discrete ventral epicranial ridges and 6 distinct stemmata. Similar in body form to larvae of Chrysomelidae but with well-developed lacinia and articulated galea (Lawrence 1991).
Life History
Adults are sometimes found in the soil of young trees in nurseries (Lawrence 1991 and Lawrence et al. 2000) and as washup or windblown drift on beaches (Johnson 2000). Larvae burrow through moss layers and underlying…
Adults are sometimes found in the soil of young trees in nurseries (Lawrence 1991 and Lawrence et al. 2000) and as washup or windblown drift on beaches (Johnson 2000). Larvae burrow through moss layers and underlying substrate (Johnson 2000). When disturbed, adults pull in their appendages and remain motionless. This behaviour creates the appearance of a small pebble or pill, hence the common name (El-Moursy 1961).
Conservation
Common in Alberta.
Diet Info
Both adults and larvae are herbivorous on the leaves and rhizoids of mosses and liverworts (El-Moursy 1961 and Lawrence et al. 2000).
Range
This species is known in North America only in the west; eastern Alberta to the Pacific coast and from Yukon Territory to California and Colorado (El-Moursy 1970).
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Citation
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Page Citation for Byrrhus eximius
Page Citation
"Species Details - Byrrhus eximius, University of Alberta E.H. Strickland Entomological Museum." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/g/2-4731. Accessed 09 Apr. 2025.
References
AuthorEl-Moursy, A. A.
TitleA tentative classification of and a key to the North American genera of the family Byrrhidae (New Sense) and family Syncalyptidae (New Status)
Publication Date1961
Series TitleThe Coleopterists Bulletin
Volume15(1)
Pages9-15
AuthorJohnson, P. J.
TitleAmerican beetles.
Publication Date2002
Pages113-116
AuthorLawrence, J.F., A.M. Hastings, M.J. Dallwitz, T.A. Paine and E.J. Zurcher.
TitleElateriformia (Coleoptera): descriptions, illustrations, identification and information retrieval for families and subfamilies.
Publication Date2000
AuthorLawrence, J. F.
TitleImmature Insects.
Publication Date1991
Pages384-386
AuthorJohnson, P. J.
TitleTaxonomic notes, new records, and a key to the adults of North American Byrrhidae (Coleoptera).
Publication Date1991
Series TitleProceedings of the Entomological Society of Washington
Volume93
Pages322-332
AuthorDownie, N. M. and R. H. Arnett
TitleThe beetles of northeastern North America.
Publication Date1996
Volume1
Pages880 pp.
AuthorHatch, M. H.
TitleThe beetles of the Pacific Northwest.
Publication Date1961
Pages293-302
AuthorEl-Moursy, A. A.
TitleThe taxonomy of the Nearctic species of the genus Byrrhus Linnaeus (Coleoptera: Byrrhidae).
Publication Date1970
Series TitleQuaestiones Entomologicae
Volume6
Pages327-338
Specimen Information
There are 25 specimens of this Species.
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25 results plotted on map in 9 markers. Note: Only records with latitude and longitude coordinates are plotted on map.