Long-horned bees: Eucera frater lata

(Hymenoptera: [Apoidea] Apidae: Apinae: Eucerini)

Profile prepared by Matthew Shepherd, The Xerces Society for Invertebrate Conservation

Eucera frater lata is endemic to but widespread within the Columbia Basin. It has a long flight period (April to August) and probably has more than one generation per year.

red list profile

conservation status

Xerces Red List Status: Vulnerable
Other Rankings
Canada – Species at Risk Act: N/A
Canada – provincial status: N/A
Mexico: N/A
USA – Endangered Species Act: N/A
USA – state status: N/A
NatureServe: N/A
IUCN Red List: N/A

Eucera frater lata has been recorded in a range of habitat types, is apparently widespread within in the Columbia Basin, and fairly common where it occurs. Given this, its population is relatively secure.

taxonomic status

Initially assigned to the genus Synhalonia (Hurd 1979), which is now a subgenus of Eucera (Michener 2000).

life history

Knowledge of the biology of Eucera frater lata is limited. Records indicate that its flight period is between April and August (Tepedino and Griswold, 1995). Given this long flight period, Tepedino and Griswold (1995) suggest that there is more than one generation per year (multivoltine). It is likely that this subspecies nests in the ground, as is usual for eucerine bees. They generally dig vertical tunnels in flat ground, from which a series of horizontal lateral burrows are excavated, each ending in a single cell (Michener, 2000). Eucera frater lata prefers to visit flowers of milkvetch (genus Astragalus).

It has been recorded in a number of habitat types within the Columbia Basin, including Interior Ponderosa Pine, Idaho fescue/slender wheatgrass, and Englemann spruce-subalpine fir, Agricultural, and Mixed grass-ag-shrub.


Eucera frater lata is endemic to but widespread in the Columbia Basin.

threats and conservation needs

Eucera frater lata is apparently widespread in the Columbia Basin and its future is relatively secure.

Some important conservation needs are to ensure that suitable flowering plants persist and that appropriate nesting substrate remains. Further information on the foraging preferences and pollinating behavior would be valuable, as would confirmation of its nesting habits. Phenological studies should be done to confirm if Eucera frater lata is univoltine or multivoltine.


Michener, C.D. 2000. The Bees of the World. Baltimore, MD: Johns Hopkins University Press.

Tepedino, V.J., and T.L. Griswold. 1995. The bees of the Columbia Basin. Final report, USDA Forest Service, Portland, OR. 212 pp (Technical Report)

additional resources

Nomina Insecta Neartica (Listed as Synhalonia frater Cresson 1878 (Melissodes); accessed November 15th, 2004.)


Shepherd, M. D. 2005. Species Profile: Eucera frater lata. In Shepherd, M. D., D. M. Vaughan, and S. H. Black (Eds). Red List of Pollinator Insects of North America. CD-ROM Version 1 (May 2005). Portland, OR: The Xerces Society for Invertebrate Conservation.