Image Credit: Judy Gallagher
Cuckoo Leaf-cutting Bees: Megachilidae: (Coelioxys, Dioxys)
These cuckoo bees of leaf-cutting and petal-plucking bees are extremely distinctive in both sexes. Both sexes are large and distinctly tapering from the base of the abdomen (the female ends in a single projecting point while the males have 3 terminal spines in Coelioxys.
The female Coelioxys (on the left) has a very prominent single protrusion at the rear, while the male (on the right) has 3 smaller ones. These tails make Coelioxys unique from all other bees, except the 3-tailed male Ashmeadiella, which are smaller and parallel-sided.
Dioxys are very rarely encountered in the field; historically they are usually encountered as they emerge from experimental nesting straws designed for Megachile. As is true of Coelioxys as well, the abdomen varies from al black to black with a red base.