Wasp
The largest social wasp is the Asian giant hornet, at up to in length. The various tarantula hawk wasps are of a similar size and can overpower a spider many times its own weight, and move it to its burrow, with a sting that is excruciatingly painful to humans. The solitary giant scoliid, "Megascolia procer", with a wingspan of 11.5 cm, has subspecies in Sumatra and Java; it is a parasitoid of the Atlas beetle "Chalcosoma atlas". The female giant ichneumon wasp "Megarhyssa macrurus" is long including its very long but slender ovipositor which is used for boring into wood and inserting eggs. The smallest wasps are solitary chalcid wasps in the family Mymaridae, including the world's smallest known insect, "Dicopomorpha echmepterygis" (139 micrometres long) and "Kikiki huna" with a body length of only 158 micrometres, the smallest known flying insect.
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.