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.
Rotoita basalis
Within their natural ecosystems, other parasitic wasps are the enemies of host insects. Many species live in leaf litter: Some have reduced or absent wings, so they cannot fly. The size that parasitic wasps reach is limited by the size of their host. Smaller ones, such as "Rotoita basalis", we would expect develop inside small hosts, like insects’ eggs, or scale insects.