Cuckoo bee

Nomadinae. About 10 mm long. Probably Nomada sp.

Largest and most diverse group of cleptoparasitic "cuckoo bees". All lack a pollen-transporting apparatus and many are strikingly wasp-like in appearance.

All are cleptoparasites of other bees. They enter the nests of their hosts when the host is absent and lay their eggs into the wall of the cell. Females produce many more eggs than their hosts and these are very small.the larval parasite emerges later, after the cell has been closed by the host female, and kills the host larva. The first-instar larvae of nomadines are specially adapted for this, and possess long mandibles they use to kill the host larva, though these mandibles are lost as soon as the larva molts to the second instar, at which point it simply feeds on the pollen/nectar provisions.

Another unusual behavioral habit seen in adults of various genera is that they will frequently "sleep" while grasping onto plant stems or leaves with only their mandibles.

Many Nomada emerge very early in spring whereas other Nomada and many species in tribes such as Epeolini fly in summer and fall.