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.
Vespinae
The subfamily Vespinae contains the largest and best-known eusocial wasps, including true hornets (the genus "Vespa"), and the "yellowjackets" (genera "Dolichovespula" and "Vespula"). The remaining genus, "Provespa", is a small, poorly known group of nocturnal wasps from Southeast Asia. One genus, "Palaeovespa", has been described from the Eocene fossil record, from Colorado. Collectively, the group can be found on all continents except Antarctica, and several of these wasps are invasive species, introduced beyond their native ranges, and can be major pests.