The most well-known invertebrate may be a species of midge ("Culicoides impunctatus"), a tiny flying gnat that is the scourge of summer visitors and residents alike. Its predations result in the loss of up to 20% of summer working days in the forestry industry. Others of significance include the pine weevil, black pine beetle, clytra beetle, and the timberman, a long-horned beetle. The archaeological site at Skara Brae provided the earliest known record of the human flea, "Pulex irritans" in Europe.