Numbers
Over 400 Nearctic species in 172 genera.
Identification
Comment from Dr. Gary Gibson re: Encyrtidae:
"It is one of the families with the mesopleuron as a large, convex, cushion-like region on the side of the thorax. You may or may not be able to see...that the middle coxae are inserted at or even somewhat anterior to the middle of the mesopleuron whereas in other chalcidoids the middle coxae are inserted near the hind coxa, much more distant from the front coxae. It should also have transverse-triangular axillae on the scutellum. Other features include a very short marginal vein on the forewing. Note also the very long mesotibial spur".
Food
Parasites of an extremely wide range of species. Some attack eggs, larvae, adults or they are hyperparasitoids.
Remarks
They are very important biological controls.
Some consider that the family Aphelinidae is part of this family.
