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.
Hemipepsis ustulata
Tarantula hawks exemplify evolutionary success in insect defense. Justin Schmidt, from personal communication with John Alcock, the world’s leading "H. ustulata" expert: “They are aposematic, brightly colored and odored, and have hard, closely fitting, smooth and slippery integumentary sclerites, live long, form defensive warning aggregations, and even have sharp and effective defensive leg spines.” Unquestionably, they are some of the best-defended insects on earth. The well-documented descriptions of battles between tarantula hawk and tarantula evidence their defensive strength. In the jaws of one of the largest and most powerful spiders on earth, the tarantula hawk still almost invariably escapes unharmed. During their violent encounters, one can often hear loud crunching or snapping sounds as the tarantula attempts to crush the wasp in its jaws. Not a single wasp death in 200 tarantula encounters was recorded by Petrunkevitch, and only one wasp injury was observed in William’s extensive field studies. Their strong, slippery integumentary armor allows the wasp to slip away unharmed.