Long-horned bees: Eucera douglasiana

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

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

Eucera (Synhalonia) douglasiana is known from only one specimen and little is known of its biology or habitat needs. Tepedino and Griswold (1995) state that a monitoring program is desperately needed, and rate this bee as a very high research priority.

red list profile

conservation status

Xerces Red List Status: Vulnerable (Data Deficient)
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

The species existed in 1902 but nothing is known of it after that.

taxonomic status

Initially assigned to the genus Tetralonia, it was subsequently reclassified as Synhalonia (Hurd 1979), which is now a subgenus of Eucera (Michener 2000).

life history

The flight period of Eucera (Synhalonia) douglasiana is June to July (Tepedino and Griswold, 1995). Eucera douglasiana nests in the ground. (Eucerine nests are usually excavated in flat ground, with a series of lateral tunnels radiating from a vertical burrow.) Its flower preferences are unknown.


Only one specimen of Eucera (Synhalonia) douglasiana has ever been collected, at Steamboat Rock, Grand Coulee (Grant County, WA).

conservation needs
Important conservation needs include ensuring that suitable (unknown) flowering plants persist and that appropriate nesting substrate remains. Surveys should be conducted to establish if Eucera (Synhalonia) douglasiana still exists. Tepedino and Griswold (1995) state that a monitoring program is desperately needed, and rate this bee as a very high research priority. If populations are discovered, further studies of foraging preferences and nesting habits would be valuable.

Hurd Jr., P. D. 1979. Superfamily Apoidea, pp. 1741-2209 in K. V. Krombein, P. D. Hurd, Jr., D. R. Smith, and B. D. Burks, eds., Catalog of Hymenoptera in America north of Mexico, Vol. 2. Washington, DC: Smithsonian Institution Press.

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 douglasiana Cockerell 1906 (Tetralonia); accessed November 15th, 2004.)

California Academy of Sciences: Andrenidae Primary Types in CAS Collection (Accessed 2/15/05)


Shepherd, M. D. 2005. Species Profile: Eucera douglasiana. 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.