Efferia coulei

Wilcox, 1966

Northwestern Hammertail

Efferia coulei is a robber fly ( Asilidae) described by Wilcox in 1966. It occurs in the grasslands of southern British Columbia, Canada, particularly the Okanagan Valley, where it is sympatric with its closest relative Efferia okanagana. The two are genetically distinct, with approximately 7.0% divergence in oxidase I (COI) barcode sequences. As a member of the Efferia arida species group, it shares morphological affinities with E. arida and E. pinali.

Pronunciation

How to pronounce Efferia coulei: /ˈɛf.ɛr.i.ə ˈkuː.li/

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Identification

Efferia coulei can be distinguished from its closest sympatric relative Efferia okanagana by barcode analysis, with the two forming distinct COI sequence clusters. Morphological identification relies on examination of male and female genitalia; the existing key to Efferia species has been modified to accommodate E. okanagana and by extension provides context for distinguishing E. coulei. Specific external morphological characters distinguishing E. coulei from related species are not detailed in available sources.

Habitat

Low-elevation grasslands dominated by bluebunch wheatgrass (Pseudoroegneria spicata), particularly where soils are gravelly. The occurs in the southern Interior of British Columbia, Canada.

Distribution

Southern British Columbia, Canada, primarily the Okanagan Valley. The distribution is sympatric with Efferia okanagana in this region.

Similar Taxa

Efferia okanaganaClosest sympatric relative in the Okanagan Valley; distinguished by 7.0% COI barcode divergence and modified key characters
Efferia aridaMember of the same group; E. coulei perhaps most closely related to this species based on
Efferia pinaliMember of the same group; E. coulei perhaps most closely related to this species based on

More Details

Conservation Status

Considered a potential at risk by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), though formal assessment status is not specified in available sources.

Taxonomic Context

Belongs to the Efferia arida group. The species was used as a comparative reference in the description of Efferia okanagana, with which it shares but remains genetically distinct.