Image Credit: Martin Cooper
Cuckoo Digger Bees: (Apidae: Melecta, Xeromelecta, Zacosmia)
These are the largest and showiest of the kleptoparasitic cuckoo-bees in the Northwest. Xeromelecta and Zacosmia are late-summer to fall bees that commonly occur with their hosts on fall asters; they are characterized by distinctive patterns of medially-interrupted tergal fasciae and prominent hair bands on the thorax. Melecta are usually spring-fliers and are very common flower-visitors (quite unlike the more typical cuckoo-bees normally seen on the bare ground surface).
Species of Melecta in the left and center and Xeromelecta on the right. Note the interrupted abdominal tergal fasciae.