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.
Largest organisms
The largest arthropod known to have existed is the eurypterid (sea scorpion) "Jaekelopterus", reaching up to in body length, followed by the millipede relative "Arthropleura" at around in length. Among living arthropods, the Japanese spider crab ("Macrocheira kaempferi") is the largest in overall size, the record specimen, caught in 1921, had an extended arm span of and weighed about . The heaviest is the American lobster ("Homarus americanus"), the largest verified specimen, caught in 1977 off of Nova Scotia weighed and its body length was . The largest land arthropod and the largest land invertebrate is the coconut crab ("Birgus latro"), up to long and weighing up to on average. Its legs may span .Insects, a class of Arthropoda, are easily the most numerous class of organisms, with over one million identified species, and probably many undescribed species. The heaviest insect is almost certainly a species of beetle, which incidentally is the most species-rich order of organisms. Although heavyweight giant wetas ("Deinacrida heteracantha") are known, the elephant beetles of Central and South America, ("Megasoma elephas") and ("M. actaeon"), the Titan beetle ("Titanus giganteus") of the neotropical rainforests or the Goliath beetles, ("Goliathus goliatus") and ("G. regius"), of Africa's rainforests are thought to reach a higher weight. The most frequently crowned are the Goliath beetles, the top known size of which is at least and . The elephant beetles and titan beetle can reach greater lengths than the Goliath, at up to , respectively, but this is in part thanks to their rather large horns. The Goliath beetle's wingspan can range up to .