Chalcid wasp
Encyclopedia
Chalcid wasps belong to the insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

 order Hymenoptera
Hymenoptera
Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...

, and are one of the largest groups within the order, with some 22,000 known species, and an estimated total diversity of anywhere from 60,000 to more than 500,000 species, meaning the vast majority have yet to be discovered and described.

Most of the species are parasitoid
Parasitoid
A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism in a relationship that is in essence parasitic; unlike a true parasite, however, it ultimately sterilises or kills, and sometimes consumes, the host...

s of other insects, attacking the egg or larval stage of their host, though many other life cycles are known. These hosts are to be found in at least 12 different insect orders including Lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

 (butterflies and moths), Diptera
Diptera
Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...

 (true flies), Coleoptera
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...

 (beetles), Hemiptera
Hemiptera
Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...

 (true bugs), and other Hymenoptera, as well as two orders of Arachnida, and even one family of nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...

s.

A few species are phytophagous and the larvae feed inside seeds, stems, and gall
Gall
Galls or cecidia are outgrowths on the surface of lifeforms caused by invasion by other lifeforms, such as parasites or bacterial infection. Plant galls are abnormal outgrowths of plant tissues and can be caused by various parasites, from fungi and bacteria, to insects and mites...

s. Generally beneficial to humans as a group, chalcids keep various crop pests under control, and many species have been imported to control insect pests.

They can be found almost everywhere, particularly on flowers, foliage, and in leaf litter, but are often overlooked due to their very small size, which includes the smallest of all known insects (Dicopomorpha echmepterygis
Dicopomorpha echmepterygis
Dicopomorpha echmepterygis is a parasitic wasp in the family Mymaridae. The males of this species are the smallest of all known insects. They are blind and wingless and may be no more than 0.139 mm in length . Females are 40% larger...

).

Chalcids are tiny, dark-coloured wasps, often metallic blue or green with complex sculpturing on the body. They are also recognized by the characteristic reduced wing venation, similar to that seen in other superfamilies of parasitic wasp
Parasitic wasp
The term parasitoid wasp refers to a large evolutionary grade of hymenopteran superfamilies, mainly in the Apocrita. They are primarily parasitoids of other animals, mostly other arthropods...

s. They have a significant part to play in ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

s and their true importance must not be underestimated.

Taxonomy

Chalcidoidea is a superfamily
Taxonomic rank
In biological classification, rank is the level in a taxonomic hierarchy. Examples of taxonomic ranks are species, genus, family, and class. Each rank subsumes under it a number of less general categories...

 of Hymenoptera
Hymenoptera
Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...

, whose family constituency is in constant flux, as new hypotheses of relationships are constantly being proposed and rejected; with the advent of molecular systematics, it seems that the future will see further revisions of the classification in use today.

There are nineteen extant families recognized at present:
  • Agaonidae Walker
    Francis Walker (entomologist)
    Francis Walker was an English entomologist. He was one of the most prolific authors in entomology, and stirred controversy during his later life as his publications resulted in a huge number of junior synonyms....

    , 1846
  • Aphelinidae
    Aphelinidae
    Aphelinidae is a moderate-sized family of tiny parasitic wasps, with some 1160 described species in some 35 genera. These minute insects are challenging to study as they deteriorate rapidly after death unless extreme care is taken , making identification of most museum specimens difficult...

     Thomson
    Carl Gustaf Thomson
    Carl Gustaf Thomson was a Swedish entomologist.Thomson became a student in the University of Lund in 1843 , graduated in 1850 and became associate professor of zoology there in 1857...

    , 1876
  • Chalcididae
    Chalcididae
    The Chalcididae are a moderate-sized family within the Chalcidoidea, composed mostly of parasitoids and a few hyperparasitoids. The family is apparently polyphyletic, though the different subfamilies may each be monophyletic, and some may be elevated to family status in the near future. As...

     Latreille
    Pierre André Latreille
    Pierre André Latreille was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, and only regained his freedom after recognising a rare species he found in the prison, Necrobia ruficollis...

    , 1817
  • Encyrtidae
    Encyrtidae
    Encyrtidae is a large family of parasitic wasps, with some 3710 described species in some 455 genera . The larvae of the majority are primary parasitoids on Hemiptera, though other hosts are attacked, and details of the life history can be variable Encyrtidae is a large family of parasitic wasps,...

     Walker
    Francis Walker (entomologist)
    Francis Walker was an English entomologist. He was one of the most prolific authors in entomology, and stirred controversy during his later life as his publications resulted in a huge number of junior synonyms....

    , 1837
  • Eucharitidae
    Eucharitidae
    Eucharitidae is a family of parasitic wasps known as Eucharitid wasps. Eucharitid wasps are members of the superfamily Chalcidoidea and consist of three subfamilies: Oraseminae, Eucharitinae, and Gollumiellinae. There are 53 genus and 473 species of Eucharitidae; most of which are members of the...

     Latreille
    Pierre André Latreille
    Pierre André Latreille was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, and only regained his freedom after recognising a rare species he found in the prison, Necrobia ruficollis...

    , 1809
  • Eulophidae
    Eulophidae
    Eulophidae is a large family of hymenopteran insects, with over 4,300 described species in some 300 genera . The family as presently defined also includes the genus Elasmus, which was previously treated as a separate family, "Elasmidae", and is now treated as a subfamily of Eulophidae...

     Westwood
    John Obadiah Westwood
    John Obadiah Westwood was an English entomologist and archaeologist also noted for his artistic talents.Born in Sheffield, he studied to be a lawyer but abandoned that for his scientific interests....

    , 1829
    (including Elasmidae)
  • Eupelmidae
    Eupelmidae
    Eupelmidae is a family of parasitic wasps in the superfamily Chalcidoidea. The group is apparently polyphyletic, though the different subfamilies may each be monophyletic, and may be elevated to family status in the near future. As presently defined, there are over 905 described species in 45 genera...

     Walker
    Francis Walker (entomologist)
    Francis Walker was an English entomologist. He was one of the most prolific authors in entomology, and stirred controversy during his later life as his publications resulted in a huge number of junior synonyms....

    , 1833
  • Eurytomidae
    Eurytomidae
    Eurytomidae is a family within the superfamily Chalcidoidea. The group is apparently polyphyletic, though the different subfamilies may each be monophyletic, and may be elevated to family status in the near future...

     Walker
    Francis Walker (entomologist)
    Francis Walker was an English entomologist. He was one of the most prolific authors in entomology, and stirred controversy during his later life as his publications resulted in a huge number of junior synonyms....

    , 1832
  • Leucospidae
    Leucospidae
    The Leucospidae are a small, specialized group within the Chalcidoidea, composed exclusively of ectoparasitoids of aculeate wasps or bees. They are typically mimics of bees or stinging wasps, often black with yellow, red, or white markings, sometimes metallic, with a robust mesosoma and very...

     Fabricius
    Johan Christian Fabricius
    Johan Christian Fabricius was a Danish zoologist, specialising in "Insecta", which at that time included all arthropods: insects, arachnids, crustaceans and others...

    , 1775
  • Mymaridae Haliday
    Alexander Henry Haliday
    Alexander Henry Haliday, also known as Enrico Alessandro Haliday and Alexis Heinrich Haliday sometimes Halliday , was an Irish entomologist. He is primarily known for his work on Hymenoptera, Diptera and Thysanoptera, but Haliday worked on all insect orders and on many aspects of entomology.Haliday...

    , 1833
  • Ormyridae
    Ormyridae
    Ormyridae is a small family of parasitic wasps in the superfamily Chalcidoidea. They are either parasitoids or hyperparasitoids on gall-forming insects, primarily cynipid wasps and tephritid flies...

     Förster
    Arnold Förster
    Arnold Förster was a German entomologist, who worked mainly on Coleoptera and Hymenoptera.-Life:Arnold Förster, who was born on 20 January 1810 in Aachen, Germany, where he died on 12 August 1884. He was Oberlehrer , or upper teacher, in Aachen for his entire adult life. He worked ceaselessly on...

    , 1856
  • Perilampidae
    Perilampidae
    The Perilampidae are a small family within the Chalcidoidea, composed mostly of hyperparasitoids. The family is closely related to the Eucharitidae, and the eucharitids appear to have evolved from within the Perilampidae, thus rendering the family paraphyletic...

     Latreille
    Pierre André Latreille
    Pierre André Latreille was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, and only regained his freedom after recognising a rare species he found in the prison, Necrobia ruficollis...

    , 1809
  • Pteromalidae
    Pteromalidae
    Pteromalidae is a very large family of parasitic wasps, with some 3,450 described species in some 640 genera...

     Dalman
    Johan Wilhelm Dalman
    Johan Wilhelm Dalman was a Swedish physician and a naturalist. He first studied at Christianfeld in Schleswig-Holstein then at the University of Lund and the University of Uppsala. He was mainly interested in entomology and botany...

    , 1820
  • Rotoitidae
    Rotoitidae
    Rotoitidae is a very small family of rare, relictual parasitic wasps in the superfamily Chalcidoidea. There are only two species known, each in their own genus, one from New Zealand and one from Chile. They are the most recently-discovered family of chalcidoids , and nothing is known about their...

     Bouček & Noyes
    Noyes
    Noyes, a surname and place name, may refer to:Norreys may refer to various members of, or estates belonging to, a landed family chiefly seated in the English counties of Berkshire and Lancashire....

    , 1987
  • Signiphoridae
    Signiphoridae
    Signiphoridae is a small family of parasitic wasps in the superfamily Chalcidoidea. There are approximately 80 species in 4 genera.-Diagnosis:...

     Ashmead
    William Harris Ashmead
    William Harris Ashmead was an American entomologist born on 19 September 1855 at Philadelphia. He died 17 October 1908 at Washington D.C.After his studies in Philadelphia, Ashmead worked for the publisher J. B. Lippincott Co. Later, he settled in Florida where he formed his own publishing house...

    , 1880
  • Tanaostigmatidae
    Tanaostigmatidae
    Tanaostigmatidae is a small family of parasitic wasps in the superfamily Chalcidoidea. They are almost exclusively phytophagous insects, forming galls in plant stems, leaves, or seeds...

     Howard, 1890
  • Tetracampidae
    Tetracampidae
    Tetracampidae is a small family of parasitic wasps in the superfamily Chalcidoidea. They are parasitoids of phytophagous insects, primarily flies. There are 44 species in 15 genera, and they are almost entirely absent from the New World....

     Förster
    Arnold Förster
    Arnold Förster was a German entomologist, who worked mainly on Coleoptera and Hymenoptera.-Life:Arnold Förster, who was born on 20 January 1810 in Aachen, Germany, where he died on 12 August 1884. He was Oberlehrer , or upper teacher, in Aachen for his entire adult life. He worked ceaselessly on...

    , 1856
  • Torymidae
    Torymidae
    Torymidae is a family of wasps that consists of attractive metallic species with enlarged hind legs, and generally with a long ovipositor. Many are parasitoids on gall-forming insects, and some are phytophagous species, sometimes usurping the galls formed by other insects. There are over 960...

     Walker
    Francis Walker (entomologist)
    Francis Walker was an English entomologist. He was one of the most prolific authors in entomology, and stirred controversy during his later life as his publications resulted in a huge number of junior synonyms....

    , 1833
  • Trichogrammatidae
    Trichogrammatidae
    The family Trichogrammatidae are tiny wasps in the Chalcidoidea that include some of the smallest of all insects, with most species having adults less than 1 mm in length. There are over 840 species in ca. 80 genera worldwide. Trichogrammatids parasitize the eggs of many different orders of insects...

     Haliday
    Alexander Henry Haliday
    Alexander Henry Haliday, also known as Enrico Alessandro Haliday and Alexis Heinrich Haliday sometimes Halliday , was an Irish entomologist. He is primarily known for his work on Hymenoptera, Diptera and Thysanoptera, but Haliday worked on all insect orders and on many aspects of entomology.Haliday...

    , 1851


There is also one extinct family, Khutelchalcididae Rasnitsyn
Alex Rasnitsyn
Rasnitsyn, Alexandr Pavlovich — Soviet and Russian entomologist, expert in palaeoentomology. Honored Scientist of Russian Federation ....

, Basibuyuk & Quicke, 2004
.

Of these families, at least five are known to be artificial groups (paraphyletic), and are being - or will be - divided into several families, or perhaps fused with existing families. The most problematic, the Pteromalidae, is, in some classifications, supposed to contain as many as 8 independent lineages, grouped together because of superficial similarities.

Identification

  • Key to families Grissell, E. E., and M. E. Schauff. 1990. A handbook of the families of Nearctic Chalcidoidea (Hymenoptera).Entomological Society of Washington (Washington, D.C.) Handbook 1:1-85.Online at http://www.codex.begoniasociety.org/chalcidkey/


External links

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