Translocation of a sand-associated blister beetle due to urban development in Uppsala, Sweden

Summary

The blister beetle (Apalus bimaculatus), a Swedish species dependent on ephemeral sandy habitats and on stable colonies of a specific host bee it parasitizes, faced the loss of one of its largest and most stable populations to urban expansion in Uppsala, prompting Sweden's first attempt to translocate the species. A 2016 spring census found only two beetles at the doomed site, alongside five patches of host-bee nesting holes nearby, confirming on-site preservation was impossible. Three candidate release areas within a kilometre, chosen for matching sandy soil and sun exposure and clear of development plans, were prepared in August 2016 by excavating 5x5 metre pits to 0.6 metre depth and carefully transplanting intact sand containing dormant bee and beetle larvae from the source site, with a reference plot dug using sand lacking known nests; stone borders and information signs were added to deter foot traffic. A census the following spring found both the beetle and its host bee present and completing development at only one of the four prepared areas, with no detections at the other three. Because the project began too close to the site's clearance date, only one of the four translocation areas is guaranteed permanent, and late-installed signage led to public confusion, including safety concerns near a nearby preschool. The project rates itself a failure so far, noting it is too early to confirm reproduction or establishment, though it demonstrates that careful sand relocation in late summer can keep both species alive through translocation, with ten years of planned monitoring to follow.