Rapid conservation evidence for the impact of sheep grazing on a threatened digger wasp

Insect populations show strong temporal fluctuations in abundance. This renders classical monitoring studies extremely difficult to provide insights into specific management actions. For rare species of conservation concern, it is not an option develop large scale experiments assess and steer landscape-level actions such as grazing management. Bembix rostrata (Linnaeus, 1758) a threatened digger wasp from coastal dunes inland sandy regions occurring limited number NW Europe. Since are rapidly being encroached by bushes, (cattle, sheep, horses) has been implemented keep this biotope open. In order for local evidence based conservation, BACI (before/after control/impact) experiment was set up the impact sheep on B. rostrata. We quantified nests during 3 years at two grazed sites control-site excluded grazing. additionally assessed pressure. The design allowed us directly adjust current reduced densities rostrata, but did lead its extinction. discuss these findings relation biology species. Our efficient effective experimental fast assessment showed that spatially heterogeneous could be used tool ensure emblematic