Johnson Prairie Butterfly Mapping

Johnson prairie has historically supported one of the more diverse and abundant butterfly communities on Fort Lewis. Despite weed control efforts, invasive grasses flourish in some areas, and some species of butterflies appear to be declining, especially noteworthy is the state monitor species the valley silverspot (also known as the zerene fritillary). Management activities to control invasive plants and favor native forbs are expected to increase on Johnson prairie in the upcoming years to improve conditions for butterflies. In an effort to inform management planning, and minimize impacts on the butterfly community, we are developing a baseline map of adult butterfly habitat use and Viola adunca distribution, the presumed host plant for two resident silverspot butterflies. This approach of mapping adult and larval habitat sites could serve as a model for site-based grassland restoration efforts elsewhere targeting butterflies or other invertebrates with multiple life stages.