In Minnesota, there are twenty-six described species within the genus Sphecodes. Bees in this genus are cleptoparasitic (cuckoo bees). Their hosts include sweat bees within the genera Halictus, Augochlorella, Augochloropsis, and Lasioglossum as well as ground-nesting Andrena, Colletes, Calliopsis, and Perdita. Additional ground-nesting hosts are possible because the host relationship information for Sphecodes is understudied.

Sphecodes have a black head and thorax, and either an entirely red abdomen or red abdomen with black markings (although some species can have an entirely black abdomen). Most species have three forewing submarginal cells; a minority have two. Females lack pollen-collecting structures. Bees in this genus can be extremely small- to medium-sized and range in length from 2 to 13 mm (0.07 to 0.5 inches). The physical size of a given species often, but not always, is similar in size to the host. 
 

Sphecodes females can be observed on flowers or near their host's ground nest, perching on the ground or on vegetation next to the nest. When the host leaves, the Sphecodes female enters the nest and searches for a fully provisioned brood cell with an egg laid on the pollen mass. Then, after destroying that egg, she lays one of her own in the brood cell. For other cuckoo bee genera, in the first instar stage, it's typical for the cuckoo bee larva to develop sickle-like mandibles that are employed to kill the host egg (or larva). These large mandibles are not present in the following instar stages of the cuckoo bee larva.