Scientific Name: Efferia okanagana
Taxonomy Group: Arthropods
COSEWIC Range: British Columbia
COSEWIC Assessment Date and Status Change: November 2011
COSEWIC Status: Endangered
COSEWIC Status Criteria: B2ab(iii)
COSEWIC Reason for Designation:
This Canadian endemic is known from only five locations within a very small area of south central British Columbia. The species’ grassland habitat is limited and continues to be degraded. Threats include introduction and spread of invasive species, changing fire regimes, pesticide drift and unrestricted ATV use.
COSEWIC History of Status Designation: Designated Endangered in November 2011.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2017-02-03
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
Efferia okanagana Cannings (Okanagan Efferia-working common name) is a large (up to about 2 cm long), brown, bristly fly in the family Asilidae (robber flies). Both sexes have striking orange-golden bristles behind the eyes. In the male, the external genitalia at the tip of the abdomen are large and hammer-shaped; the last three visible abdominal segments are silver-white. The female has a long, sword-shaped ovipositor at the end of the abdomen. There are no subspecies known. The larva and pupa are unknown. This robber fly is significant because it is one of the more obvious large invertebrates representative of the Antelope-brush ecosystem in Canada. Much of this habitat is threatened and, as yet, the fly is unknown from anywhere else in the world. [Updated by COSEWIC - Nov. 2011]
Distribution and Population
The known global distribution of the fly is restricted to five locations (28 individual sites) in the Okanagan and Thompson valleys of south-central British Columbia, from Kamloops in the north, to Oliver in the south. Population sizes have not been estimated. Populations are patchily distributed in suitable habitat at the regional scale and density is extremely variable at the site scale. In appropriate habitat, thirty-minute searches can produce catches of up to 15 specimens; usually the range is 0 to 5. There is no direct information on population trends, although declines can be inferred from trends in habitat destruction. In the southern part of the species’ range, Antelope-brush steppe, the main habitat of the fly, has declined by two-thirds since European settlement.[Updated by COSEWIC - Nov. 2011]
The Okanagan Efferia is apparently restricted to dry grasslands growing on gravelly or sandy loam soils. Open soil is usually present, as is Bluebunch Wheatgrass. In the South Okanagan, the species has been found only in Antelope-brush steppe. [Updated by COSEWIC - Nov. 2011]
Robber flies are generalist predators of other insects, both as larvae and adults. The adults of Okanagan Efferia have been recorded capturing leafhoppers, click beetles, leafcutter and andrenid bees and ants, micromoths, flower flies, crane flies and robber flies. Prey is seized in the fly’s bristly legs and the prominent proboscis is inserted in the prey’s body. Paralyzing, proteolytic saliva is injected and the tissues are dissolved; the resulting fluid is sucked up by the fly. Eggs are laid in the empty glumes of the previous year’s wheatgrass inflorescences. It is assumed that, like most other robber flies, larvae feed on soil invertebrates such as beetle larvae. The larval period lasts 1-2 years; pupation evidently occurs in the last spring and the adults emerge in late April or early May. The Okanagan Efferia has been collected or photographed from 17 April to 18 June, with most records falling in the middle weeks of May. [Updated by COSEWIC - Nov. 2011]
Threats to the Okanagan Efferia include habitat loss or degradation (development, especially of vineyards; overgrazing by livestock; damage by vehicles), wild fires and related changes, invasive plants, climate warming, and pesticide effects. There is no detailed information on limiting factors. There is an apparent, unmeasured correlation of the species’ presence with Bluebunch Wheatgrass growing on gravelly soils. The well-drained character of these soils, or some other features, may be limiting requirements of the soil-dwelling larvae. The only oviposition sites observed are the empty glumes in the old inflorescences of this grass species. Larvae feed on subterranean insect larvae and the availability of suitable prey may be limiting. Adults are opportunistic, general predators of flying insects and locating suitable prey is likely not limiting. [Updated by COSEWIC - Nov. 2011]
The Okanagan Efferia is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Okanagan Efferia (Efferia okanagana) in Canada
Status First posting on SAR registry
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
8 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Related Information (1 record(s) found.)
COSEWIC Status Reports
Response Statement - Okanagan Efferia (2013-01-03)This Canadian endemic is known from only five locations within a very small area of south central British Columbia. The species’ grassland habitat is limited and continues to be degraded. Threats include introduction and spread of invasive species, changing fire regimes, pesticide drift and unrestricted ATV use.
COSEWIC Annual Reports
COSEWIC Annual Report - 2011-2012 (2012-10-05)Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings in this reporting year (September 1, 2011 to September 30, 2012) from November 21 to 25, 2011 and from April 29 to May 4, 2012. On February 3, 2012, an Emergency Assessment Subcommittee of COSEWIC also assessed the status of the Tri-colored Bat (Perimyotis subflavus), the Little Brown Myotis (Myotis lucifugus), and the Northern Myotis (Myotis septentrionalis). During the current reporting period COSEWIC assessed the status or reviewed the classification of 67 wildlife species. For species already found on Schedule 1 of SARA, the classification of 32 species was reviewed by COSEWIC and the status of the wildlife species was confirmed to be in the same category (extirpated - no longer found in the wild in Canada but occurring elsewhere, endangered, threatened or of special concern). The wildlife species assessment results for the 2011-2012 reporting period include the following: Extinct: 1 Extirpated: 4 Endangered: 29 Threatened: 10 Special Concern: 15 Data Deficient: 2 Not at Risk: 6 Total: 67 Of the 67 wildlife species examined, COSEWIC reviewed the classification of 49 species that had been previously assessed. The review of classification for 26 of those species resulted in a confirmation of the same status as the previous assessment (see Table 1a).