Fairyfly

The Mymaridae, commonly known as fairyflies or fairy wasps, are a family of chalcidoid wasps found in temperate, subtropical, and tropical regions throughout the world. They are very tiny insects, usually ranging from 0.5 to 1.0 mm long, and include the world's smallest known insect and the smallest known flying insect.

Fairyflies have interesting features, such as nonmetallic black, brown, or yellow bodies and wings that look feathery or hairy. These wings help them move through the air, which feels like moving through honey at their size. Because they are so small, fairyflies are often unnoticed by humans.

All known fairyflies live by placing their eggs inside the eggs of other insects. Some species have been used to help control pests that harm plants, making them important for keeping gardens and farms healthy. Their adult lives are very short, usually only a few days.

Taxonomy

The family Mymaridae was first described in 1833 by an Irish scientist named Alexander Henry Haliday. He and his friends John Curtis and Francis Walker were important in studying a group of insects called Hymenoptera in the 1800s.

Fairyflies were originally called "Mymares" and were part of another group called "Chalcides." Later, they were given their own family name, Mymaridae. These tiny insects were popular among scientists and microscope users in the late 1800s and early 1900s because of their beautiful wings. Today, there are about 1,424 known species of fairyflies, grouped into around 100 different types. Some of the most common types include Anagrus, Anaphes, Gonatocerus, and Polynema.

Description

Fairyflies are tiny insects, usually about as long as a grain of rice. They are often black, brown, or yellow and have long antennae. Their wings are usually flat and can be very narrow or wide, depending on the species. Some fairyflies have very small wings or no wings at all, especially those that live in windy places or tight spaces.

Distribution and habitat

Fairyflies are very tiny insects that are found all over the world, especially in temperate and tropical areas. They live in many different places, from deserts to rainforests, and some can even live in water, like in freshwater ponds and streams. One special type, called Caraphractus cinctus, can swim using its wings and stay underwater for up to 15 days. Because they are so small, fairyflies often go unnoticed by people.

Ecology

Fairyflies are tiny insects that lay their eggs inside the eggs of other insects. These other insects are called hosts, and fairyflies do not choose specific types of hosts. Common hosts include true bugs like leafhoppers and cicadas, as well as beetles, flies, dragonflies, booklice, and thrips.

Fairyflies include some of the smallest insects known. One species from Illinois has males that are only about 0.14 mm long—so small that four lined up would just about fit across the width of a period at the end of a sentence. These tiny males do not have wings or eyes, and their bodies are smaller than a single-celled organism called a Paramecium. The females, however, are typical fairyfly size. Another tiny species from Hawaii is the smallest known flying insect, measuring just 0.15 mm.

Economic importance

Fairyflies are important because they help control pests that can damage crops. They are especially good at finding the eggs of pests, which makes them useful for protecting plants. One group of fairyflies, called Anagrus, has been used in many places to reduce pest numbers.

For example, in Hawaii, a type of fairyfly called Anagrus optabilis was used to control a pest that harms sugarcane. In California, fairyflies were helped by planting wild blackberries to give them food during winter. They have also been used to control pests on grapes and other plants. In places like Tahiti and Moorea, fairyflies reduced pest numbers by up to 95% in just one year. These tiny insects are valuable helpers in keeping farms healthy and productive.

Fossil record

Fairyflies have been found preserved in fossil amber inclusions, copal, and compression fossils from as far back as the Early Cretaceous to the Miocene epoch. Scientists have discovered these tiny insects in fossils from different times in Earth's history.

Researchers first described fairyfly fossils in 1901, finding them in Baltic amber from the Eocene period. More discoveries followed, with fossils found in Burdigalian amber from Mexico and in the oil shales of Montana. The oldest known fairyfly, from the Cenomanian age of the Late Cretaceous, was found in Burmese amber. These ancient fairyflies look quite similar to the ones alive today, showing that these tiny insects have changed very little over millions of years.

Genera

The Mymaridae family includes many small genera of fairyflies. Some names have changed over time, and a few were found to be made as jokes. Most of these insects are very tiny, measuring from about half a millimeter to one millimeter long.

Extant genera

• Acanthomymar Subba Rao, 1970
• Acmopolynema Ogloblin, 1946
• Acmotemnus Noyes & Valentine, 1989
• Agalmopolynema Ogloblin, 1960
• Alaptus Ferrière, 1930
• Allanagrus Noyes & Valentine, 1989
• Allarescon Noyes & Valentine, 1989
• Anagroidea Girault, 1915
• Anagrus Haliday, 1833
• Anaphes Haliday, 1833
• Anneckia Subba Rao, 1970
• Apoxypteron Noyes & Valentine, 1989
• Arescon Walker, 1846
• Australomymar Girault, 1929
• Baburia Hedqvist, 2004
• Bakkendorfia Mathot, 1966
• Boccacciomymar Triapitysn & Berezovskiy, 2007
• Borneomymar Huber, 2002
• Boudiennyia Girault, 1937
• Bruchomymar Ogloblin, 1939
• Caenomymar Yoshimoto, 1990
• Callodicopus Ogloblin, 1955
• Camptoptera Förster, 1856
• Camptopteroides Viggiani, 1974
• Caraphractus Walker, 1846
• Ceratanaphes Noyes & Valentine, 1989
• Chaetomymar Ogloblin, 1946
• Chrysoctonus Mathot, 1966
• Cleruchoides Lin & Huber, 2007
• Cleruchus Enock, 1909
• Cnecomymar Ogloblin, 1963
• Cremnomymar Ogloblin, 1952
• Cybomymar Noyes & Valentine, 1989
• Dicopomorpha Ogloblin, 1955
• Dicopus Enock, 1909
• Dorya Noyes & Valentine, 1989
• Entrichopteris Yoshimoto, 1990
• Eofoersteria Mathot, 1966
• Erdosiella Soyka, 1956
• Erythmelus Enock, 1909
• Eubroncus Yoshimoto, Kozlov & Trjapitzin, 1972
• Eucleruchus Ogloblin, 1940
• Eustochomorpha Girault, 1915
• Eustochus Haliday, 1833
• Formicomymar Yoshimoto, 1990
• Gahanopsis Ogloblin, 1946
• Ganomymar De Santis, 1972
• Gonatocerus Nees, 1834
• Haplochaeta Noyes & Valentine, 1989
• Himopolynema Taguchi, 1977
• Idiocentrus Gahan, 1927
• Ischiodasys Noyes & Valentine, 1989
• Kalopolynema Ogloblin, 1960
• Kikiki Huber & Beardsley, 2000
• Kompsomymar Lin & Huber, 2007
• Krokella Huber, 1993
• Kubja Subba Rao, 1984
• Litus Haliday, 1833
• Macrocamptoptera Girault, 1910
• Malfattia Meunier, 1901
• Mimalaptus Noyes & Valentine, 1989
• Mymar Curtis, 1829
• Mymarilla Westwood, 1879
• Myrmecomymar Yoshimoto, 1990
• Narayanella Subba Rao, 1976
• Neolitus Ogloblin, 1935
• Neomymar Crawford, 1913
• Neostethynium Ogloblin, 1964
• Neserythmelus Noyes & Valentine, 1989
• Nesomymar Valentine, 1971
• Nesopatasson Valentine, 1971
• Notomymar Doutt & Yoshimoto, 1970
• Omyomymar Schauff, 1983
• Ooctonus Haliday, 1833
• Palaeoneura Waterhouse, 1915
• Palaeopatasson Witsack, 1986
• Paracmotemnus Noyes & Valentine, 1989
• Paranaphoidea Girault, 1913
• Parapolynema Fidalgo, 1982
• Parastethynium Lin & Huber, 2007
• Platyfrons Yoshimoto, 1990
• Platypolynema Ogloblin, 1960
• Platystethynium Ogloblin, 1946
• Polynema Haliday, 1833
• Polynemoidea Girault, 1913
• Polynemula Ogloblin, 1967
• Prionaphes Hincks, 1961
• Pseudanaphes Noyes & Valentine, 1989
• Pseudocleruchus Donev & Huber, 2002
• Ptilomymar Annecke & Doutt, 1961
• Restisoma Yoshimoto, 1990
• Richteria Girault, 1920
• Schizophragma Ogloblin, 1949
• Scleromymar Noyes & Valentine, 1989
• Steganogaster Noyes & Valentine, 1989
• Stephanocampta Mathot, 1966
• Stephanodes Enock, 1909
• Stethynium Enock, 1909
• Tanyostethium Yoshimoto, 1990
• Tetrapolynema Ogloblin, 1946
• Tinkerbella Huber & Noyes, 2013
• Zelanaphes Noyes & Valentine, 1989

Fossil genera

These fossil genera are classified under Mymaridae:

• †Carpenteriana Yoshimoto, 1975 Canadian amber, Late Cretaceous (Campanian)
• †Enneagmus Yoshimoto, 1975 Canadian amber, Campanian
• †Eoanaphes Huber in Huber & Greenwalt, 2011 Kishenehn Formation, Montana, Eocene (Lutetian)
• †Eoeustochus Huber in Huber & Greenwalt, 2011 Kishenehn Formation, Montana, Lutetian
• †Macalpinia Yoshimoto, 1975 Canadian amber, Campanian
• †Myanmymar Huber in Huber & Poinar, 2011 Burmese amber, Late Cretaceous (Cenomanian)
• †Triadomerus Yoshimoto, 1975 Canadian amber, Campanian

Collection and preservation

See also: Insect collecting

Fairyflies are tiny insects that are hard to collect, which makes them unpopular among modern insect collectors. Because they are one of the least known insect families, there is still much to learn about them, and amateur naturalists can still make important discoveries in this area.

In the past, people used special nets to catch fairyflies and carefully placed them on cards to dry. Today, the best way to collect them is by using Malaise traps, which need little care and can catch many insects. Other good methods include yellow pan trapping, sweep nets, and suction trapping. You can also find them in leaf litter using Berlese funnels.

Keeping fairyflies as specimens can be tricky because of their small size. If they are collected wet, such as when using ethyl alcohol as the killing agent, they need to be dried carefully to avoid breaking. Placing them on cards or slides takes time and practice.