A new genus of fairyfly has been discovered in Costa Rica. The new species aptly named Tinkerbella nana after the fairy in J.M. Barrie’s play ‘Peter Pan’ is one of the smallest winged insects in the neotropics.
Found in both temperate and tropical climates, the fairyfly is not actually a fly as its name suggests, but instead is more closely related to wasps – being classed within the superfamily Chalcidoidea, or the “chalcid wasps”. There are over 1,400 species of fairyfly, mostly found in the tropical environments of the southern hemisphere.
After comparisons to existing groups, a research team found that they had discovered an entirely new genus, with the new specimens being considerably smaller than the majority of other fairyfly species. Lead author of the research paper John Huber told mongabay.com that Tinkerbella nana individuals are “so small that 3 or 4 of them lined up end to end would just cover a printed full stop”, with the smallest specimen collected measuring less than 250 micrometers.
All of the currently noted specimens of Kikiki huna have been female, making male individuals unknown in the neotropics. Photo by John T. Huber.
Another fairyfly species, Kikiki huna, also located in Costa Rica, currently holds the record for being the smallest winged insect in the world, with a documented length of only 150 micrometers.
Kikiki huna specimens have previously been recorded in Trinidad and the Hawaiian Islands – where they were first discovered – and more recently in Argentina, indicating that it is widespread in Neotropical America.
The most anatomically similar genus to the new Tinkerbella species is Anagrus, but those individuals are generally much larger than 250 micrometers and no other genus of flying insect rivals Tinkerbella or Kikiki in terms of size.
The long setae on the fairyfly hindwing are believed to have a purpose in aerodynamics – reducing the drag during wing flaps. John T. Huber.
Huber believes that the English common-name “fairyfly” has derived from “[their] small size and delicate wings with long fringes, resembling the mythical fairies.” Their microscopic dimensions lead them to be near invisible, as are their elusive eponym in folklore.
Generally, fairyflies are parasitoids of insect eggs, meaning that they lay their eggs on or within those of another insect and use the host egg as a food source, ultimately killing it. The development of the host embryo within the insect egg has an important factor in the timing of fairyfly egg laying. Many species need the host embryo to be slightly developed before they attack them otherwise the fairyfly offspring aren’t likely to mature, however in other species the fairyfly larvae is less likely to survive if the insect embryo is too far advanced, as they become harder to digest.
CITATION: John T. Huber, John S. Noyes. A new genus and species of fairyfly, Tinkerbella nana (Hymenoptera, Mymaridae), with comments on its sister genus Kikiki, and discussion on small size limits in arthropods. Journal of Hymenoptera Research, 2013.