Wasp
Wasps first appeared in the fossil record in the Jurassic, and diversified into many surviving superfamilies by the Cretaceous. They are a successful and diverse group of insects with tens of thousands of described species; wasps have spread to all parts of the world except for the polar regions. The largest social wasp is the Asian giant hornet, at up to in length; among the largest solitary wasps is a group of species known as tarantula hawks, along with the giant scoliid of Indonesia ("Megascolia procer"). The smallest wasps are solitary chalcid wasps in the family Mymaridae, including the world's smallest known insect, with a body length of only , and the smallest known flying insect, only long.
Chrysidinae
The subfamily Chrysidinae contains those species that are most commonly recognized as cuckoo wasps, being by far the largest and most familiar subfamily. The group contains some 3000 species in 48 genera in four tribes worldwide. They are highly sculptured, with brilliantly metallic-coloredbodies, and capable of folding their bodies over (or, more commonly, rolling into a ball) as a defensive mechanism. They are most diverse in desert regions of the world, as they are typically associated with solitary bee and wasp species, which are also most diverse in such areas.