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
The nests of "P. jacobsoni" generally reach their maximum size at 48 cells, and can house up to 6 females and 6 males, as well as a total of 33 larvae in a brood. "P. jacobsoni" wasps always use plant matter to construct their nests. They are composed of one or two linear rows anchored on a slim support or scattered across a flat surface. According to the theory that conserving material by utilizing wall-sharing cells and constructing structures to protect the nest are evidence of evolved wasp characters, "P. jacobsoni" constructs nests that are perhaps the most primitive of all wasp nests. It has almost no wall-sharing whatsoever, with cells scattered across the underside of a leaf. The nest, similar to that of "P. nigricans serrei", differs particularly because the alveolar walls are adjoined to the neighboring cells and because pupal cells, instead of being sealed, are simply narrowed.