Bees appear in recent classifications to be a specialized lineage of crabronid wasps that switched to the use of pollen and nectar as larval food, rather than insect prey; this presumably makes the Crabronidae a paraphyletic group. Accordingly, bees and sphecoids are now all grouped together in a single superfamily, and the older available name is "Apoidea" rather than "Sphecoidea" (which, like Spheciformes, has been used in the past, but also defined a paraphyletic group and has been abandoned).
As bees (not including their wasp ancestors) are still considered a monophyletic group, it is still convenient to use a grouping between superfamily and family to unify all bees. A few recent classifications have addressed this problem by lumping all bee families together into a single large family Apidae, though this has not met with widespread acceptance. The alternative classification in more common use is to unite all bees under the name Anthophila (Engel, 2005), which is equivalent to the obsolete name Apiformes (which meant 'bee-like forms' in Latin).