While not closely related or visual similar, these two species are included together because they are closely linked and often found together. Holcopasites is a cleptoparastite of Calliopsis - both are distinctive and best found by crawling on your hands and knees around construction sites and abused ball fields.
Both of these bees are active mid-summer on small flowers growing close to the ground. Calliopsis nest in disturbed soil and can regularly be found in the weedy margins of sand pits, recreation fields, or even lawns with sparse vegetation. Holcopasites is only found where Calliopsis is present, but can be more noticeable and easier to photograph.
Nebraska Vervain Calliopsis Bee (Calliopsis nebraskensis) – Similar to the Eastern Calliopsis Bee, but a specialist on Vervain. Unrecorded from Vermont and very rare in the east.
Dusty Cuckoo Nomad Bee (Holcopasites illinoiensis) – Also a cleptoparasite of the Eastern Calliopsis Bee. Similar to Calliopsis Cuckoo Nomad Bee, but with white stripe instead of white dots. Very rare in the Northeast, but recorded from Maine and Massachusetts.
Unless otherwise specified, photos are courtesy of Margarita Miklasevskaja at PCYU with funding from NSERC-CANPOLIN.