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.
Parischnogaster jacobsoni
Parischnogaster jacobsoni is a species of social wasp within "Parischnogaster", the largest and least known genus of Stenogastrinae. It is distinguished mainly by its tendency to construct ant guards on its nests. Natural selection has led this wasp to have a thick substance emitted from its abdominal glands that allows it to protect its nest from invasions. "Parischnogaster" as a genus has been relatively unstudied; "P. jacobsoni" is one of the few investigated species because it has sufficient durability to live near human populations and it has demonstrated unusual resilience to pollution. While "P. jacobsoni" is a more complex organism than other wasps in "Parischnogaster", the genus overall is relatively primitive with respect to social wasps as a whole.