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.
Parasitoid wasp
Many parasitoid wasps use larval Lepidoptera as hosts, but some groups parasitize different host life stages (egg, larva or nymph, pupa, adult) of nearly all other orders of insects, especially Coleoptera, Diptera, Hemiptera and other Hymenoptera. Some attack arthropods other than insects: for instance, the Pompilidae specialise in catching spiders: these are quick and dangerous prey, often as large as the wasp itself, but the spider wasp is quicker, swiftly stinging her prey to immobilise it. Adult female wasps of most species oviposit into their hosts' bodies or eggs. Some also inject a mix of secretory products that paralyse the host or protect the egg from the host's immune system; these include polydnaviruses, ovarian proteins, and venom. If a polydnavirus is included, it infects the nuclei of host hemocytes and other cells, causing symptoms that benefit the parasite.