Fairyfly discovery: Scientists find new species of minute fairyfly that is just one quarter of a millimetre long The specimens of Tinkerbella nana were discovered in Costa Rica The miniscule fairyflies are just 250 micrometres long Scientists say they do not know how small insects can be The minute Tinkerbella nana are less than 250 micrometres long It may not be as common as the Peter Pan fairy, but this newly discovered insect is the real Tinker Bell. The fairyfly species named Tinkerbella nana was discovered in the forests of Costa Rica. The miniscule specimens were all just 250 micrometres long - or one quarter of a millimetre - and collected by sweeping the forest floor. Tinkerbella nana was collected at the La Selva Biological Station and named as the newest fairyfly species. When viewed under a microscope, Tinkerbella nana's long thin wings become visible. Each is fringed with long hair-like bristles. Mymaridae, commonly known as fairyflies, are one of about 18 families of chalcid wasps. They are found across the world, except in Antarctica, but are so minute that they are seldomly noticed by humans. Their apparent invisibility and delicate wings with long fringes resembling the mythical fairies have earned them their common name. Fairyfly species include the world's smallest known winged insect, Kikiki huna, which has a body length of only 155 micrometres. The smallest known adult insect is also a fairyfly. The wingless male of Dicopomorpha echmepterygis is only 130 micrometres. Fairyflies live off the eggs and larvae of other insects. The eggs are commonly laid in concealed locations, such as in plant tissues or in leaf litter or soil. They are so small and difficult to find that most of the host insects of fairyflies are unknown. The newly discovered species were found in the young forests of Costa Rica The La Selva Biological Station has a fairy-like quality befitting of an insect names Tinkerbella There are 1,424 known species of fairyflies spread across the world. At least five are aquatic and live in freshwater ponds and streams. One, called Caraphractus cinctus, uses its wings as paddles to swim along and remain underwater for up to 15 days. The minute insects can survive in all kinds of habitats, from deserts to rainforests. They were first categorised in 1833 by the Irish entomologist Alexander Henry Haliday. Several species have been used for pest control, as fairyflies are valued for their ability to find the eggs of their hosts. John Huber, from Natural Resources Canada, was the lead author of A New Genus And Species of Fairyfly, Tinkerbella Nana published in the Journal of Hymenoptera Research. He said: 'If something is physically possible in living things, some individuals of at least one species, extinct or extant, will likely have achieved it. So the lower size limit, by whatever measure of size is chosen, was almost certainly already evolved - somewhere, sometime. If we have not already found them, we must surely be close to discovering the smallest insects and other arthropods. The Tinkerbella species were collected at the biological station owned and managed by the Organization for Tropical Studies. Little is known about the lifecycle of fairyflies. They have smaller wing surfaces and relatively long setae - or bristles - are believed to have an aerodynamic function. It may be to reduce turbulence on wings flapping at several hundred beats per second. The new fairyfly species shares a name with Peter Pan's famous friend Tinker Bell