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Helping a Threatened Butterfly Recover in Oregon

Posted by Sara Magenheimer, Oregon NRCS in Conservation
Aug 06, 2010
 

The native violet, Viola adunca, which the NRCS Corvallis Plant Materials Center is growing for silverspot butterfly habitat.
The native violet, Viola adunca, which the NRCS Corvallis Plant Materials Center is growing for silverspot butterfly habitat.

The silverspot butterfly (Speyeria zerene hippolyta) is one of two native Oregon butterfly species listed as threatened or endangered under the U.S. Endangered Species Act. Once found in coastal headlands from northern California to southern Washington, it has disappeared from all but a handful of grassland sites along the Oregon coast.

In 2005, the NRCS Corvallis Plant Materials Center (PMC) and U.S. Fish and Wildlife Service began a collaborative effort to develop a long-term seed source for silverspot butterfly habitat restoration. Since then, the PMC has been growing plugs of native violets, producing a couple of pounds of violet seed per year and distributing both to Oregon conservation groups for planting. Native violets are critical for the survival of this threatened butterfly species, as they are a larval host plant.

Harvesting violets is a complex process. The seeds are allowed to shatter on weed fabric and vacuumed up with specialized equipment. They then make their way to conservation groups all along the Oregon coast, which plant them to help reestablish critical butterfly habitat.

In 2008, the program was expanded to include sand fescue and nectar plants such as pearly everlasting, goldenrod, yarrow and pacific aster. In 2009, the PMC produced 8 lbs of violet seed, 105 lbs of fescue seed and over 20 lbs of seed of the nectar species. Approximately 4,000 violet plants were also grown for the U.S. Fish and Wildlife Service to plant at restoration sites.

Category/Topic: Conservation