This medium-sized Nomada has an overall pattern of yellow and dark brown stripes on the abdomen, with the first tergite a clear reddish brown. It can be most easily found flying over large nesting aggregations of its host bee, Andrena flavipes.

In recent years it has become apparent that the bee known as B. lucorum (Linnaeus, 1761) is in fact a species complex, containing two other species - B. magnus and B. cryptarum. Separation of the three species is very difficult, so that definitive records for any of the three species are rare.