After hatching, these Oil Beetle larvae, called triungulins, gather together at the top of a plant and begin emitting pheromones that attract male solitary bees. They then lie in wait for bees to arrive, jump on them, and if it’s a male bee, ride on him until he mates with a female bee. Then they jump onto HER and ride until she goes into her underground, solitary nest. There they decimate her store of pollen and her eggs, pupate underground, and emerge later as adult oil beetles (also called blister beetles). For a fun read and deeper look into this surprising life story click here.
Photo by Marirose Kuhlman on 4/29/20 in Florence, MT.