2 subfamilies, with >480 spp. in 150 genera in our area and >3700 spp. in 460 genera worldwide(1)
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. --Gary Gibson
Key to Nearctic genera in (2)
Antennae often sexually dimorphic: in females, clubbed with short setae and sometimes with flattened segments; males typically lack a club and often have long setae(segments never flattened). The taxonomy mostly based on females, In some species males unknown or extremely rare.
More diverse in warmer and drier areas. They can be taken from a wide variety of plants but are most common on shrubs & grasses. Malaise traps is an effective collection tool.
Parasitoids of an extremely wide range of insects (one species parasitizes ticks), but scales and mealybugs (Hemiptera) are common hosts for a large number of species. They can attack the egg, larval, or adult stage, as either a primary or secondary parasitoid.(4)
Includes many important biocontrol agents.
Specimens from most species will shrink/collapse after death, rendering identification problematic. The best way to preserve encyrtids is to keep them initially in 70‒75% ethanol, and later either critically-point dry them or treat with hexamethyldisilazine (HMDS) (toxic!).
Body colors range from drab dark-brown (or black) to orange or yellow to bright metallic green. Other chalcidoids with which they are most easily confused are the Aphelinidae (due to their general body habitus) and Eupelmidae (due to the enlarged mid-tarsal spurs and mesopleura), but encyrtids can be distinguished by their shorter (often punctiform) marginal vein. However, encyrtids are most often confused with members of the family Platygastridae that had formerly been placed under Scelionidae. Both encyrtids and "scelionids" can have a similar body habitus and forewing venation, making their separation quite difficult for the non-expert.