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The Dragonflies (Insecta: Odonata) of the Columbia Basin, British Columbia: Field Surveys, Collections Development and Public Education Table of Contents Return to Family Gomphidae Stylurus Needham Stylurus is closely allied to Gomphus. Only one of the seven Canadian species occurs in British Columbia. Stylurus olivaceus (Selys)* Olive Clubtail Provincial Status CDC rank: S2 Red List In British Columbia, Stylurus olivaceus is known only from warm streams and lakeshores in the Thompson-Okanagan and Boundary regions. Columbia-Kootenay Distribution Known only along Christina Creek. This population was discovered during the present study. Global Distribution Western North America from southern British Columbia south to Arizona and California (Bick and Mauffray 2000). Faunal element: Cordilleran (see Appendix 2). Biological information S. olivaceus inhabits sandy or muddy edged rivers or lakeshores in hot, dry areas. Christina Creek, the only location where this species was found in this study, has large sections of bank consisting of both pebbly/cobbled and sandy/muddy substrates. Adults fly over the riffles and land along the shore (present study; Cannings and Stuart 1977): they also rest on riparian vegetation. Kennedy (1917) noted that females may rest on bushes well away from the water, where they are less likely to be observed than the males along the river. Adults were recorded at Christina Creek on 7 and 28 August 1999. The range of recorded British Columbia flight dates is 28 July to 1 October (Cannings and Stuart 1977). Washington State flight records range from 8 July to 26 October (Paulson 1999). Management and protection considerations More research is needed to develop management recommendations for S. olivaceus, but its lakeshore and streamside habitat, like that of other gomphids and Macromia, is often shared with intensive human recreation use. Marina developments, pollution from power boats, and popular swimming beaches all have potential impact on larval survival. More precise knowledge of larval distribution would assist in making decisions bearing on the health of this dragonfly. The protection of the riparian zone and the maintenance of a relatively undisturbed edge along Christina Creek is vital for this species. Samways and Steytler (1996) provide recommendations for the width of riparian buffers and vegetation heterogeneity for species assemblages. Although these recommendations treat different odonate assemblages, the life requirements of the dragonfly species are similar. Stylurus uses habitat away from the river's edge; the area needed by this species remains to be determined. Control of the amount and type of recreation in the habitat is also important. Of particular concern is the use of personal watercraft (i.e. Jet Ski) along the shallow creek where this species lives. The wakes from these craft break down the banks (observed directly in this study) and ultimately collapse the streamside vegetation. The impact of introduced predatory fish, especially bass, on this rare dragonfly is unknown, but definitely of concern.

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