I photographed several insect species at two sandy sites, one in Port Angeles, WA, south of Peninsula College, and the other at the Dungeness Wildlife Refuge in Sequim, WA.
Both sites consisted of a community of species making and using holes in sandy dirt with little vegetation. In addition to the species shown here, there were leafcutting bees, at least two other wasp species and several ant species.
Philanthus wasps, also known as bee wolves, prey upon bees. The wasp captures and stings a bee—sometimes in the air. The wasps appear to light on the sand and wait for a bee to fly overhead. The wasp then drags the bee into an underground hole and lays an egg on one or more bees. After emerging from a hole, Philanthus often covers its hole, as you can see in the video (6).
Able to recognize the site of the hole after it’s covered, Philanthus lands, redigs the hole and enters in just a few seconds (making them hard to photograph digging).
Philanthus digs with its front legs while standing on the middle and back legs. In movie 1 below, a Philanthus digs into a hidden hole. In movie 2, she covers the hole, then redigs it. Movie 3 is a long, unedited clip showing the wasp lighting, digging and entering a hole, then, after a long pause, exiting and covering the hole.
Philanthus wasps are slim, with a large head, and a yellow face. Among characteristics used to identify Philanthus is a constriction between the first and second abdominal segments.
I observed Philanthus adults feeding on Pearly Everlasting (Anaphalis margaritacea), Yarrow (Achillea millefolium), and Common Tansy (Tancetum vulgare).