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.
Spider wasp
Spider wasps are solitary wasps that use a single spider as a host for feeding their larvae. They paralyze the spider with a venomous stinger. Once paralyzed, the spider is dragged to where a nest will be builtsome wasps having already made a nest. A single egg is laid on the abdomen of the spider, and the nest or burrow is closed. Spider wasps protect their nests by putting dead ants into the outermost chamber, the chemicals within deterring predators.
The size of the host can influence whether the wasp's egg will develop as a male or a female; larger prey yield the (larger) females. A complex set of adult behaviors can then occur, such as spreading soil or inspecting the area, leaving the nest site inconspicuous. When the wasp larva hatches, it begins to feed on the still-living spider. After consuming the edible parts of the spider, the larva spins a silk cocoon and pupates, usually emerging as an adult the next summer. Some ceropalines lay the egg on a still-active spider, where it feeds externally on hemolymph. In time, that spider will die, and the mature wasp larva will then pupate.