Chalcid wasps (, , for their metallic colour) are

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s within the superfamily Chalcidoidea, part of the order

Hymenoptera Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typi ...

. The superfamily contains some 22,500 known species, and an estimated total diversity of more than 500,000 species, meaning the vast majority have yet to be discovered and described. The name "chalcid" is often confused with the name "chalcidid", though the latter refers strictly to one constituent family, the

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 e ...

, rather than the superfamily as a whole; accordingly, most recent publications (e.g.,) use the name "chalcidoid" when referring to members of the superfamily. Most chalcid wasps are

parasitoids In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

of other insects, though other life styles are known, with the herbivorous

fig wasps Fig wasps are wasps of the superfamily Chalcidoidea which spend their larval stage inside fig syconia. Some are pollinators but others simply feed off the plant. The non-pollinators belong to several groups within the superfamily Chalcidoidea, ...

acting as

pollinators A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains. Insects are the ma ...

. Various species are used as

biological pest control Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or ot ...

agents or in scientific research.

Description

Chalcidoids are generally small wasps, averaging 1.5 mm in length and usually being less than 3 mm. The body is often metallic in colour. The wings may be developed, reduced or absent. When the wings are developed, they have reduced venation or sometimes none at all. However, the group is morphologically very diverse. Chalcidoids range in size from up to 41.7 mm long (females of the pelecinellid ''

Doddifoenus wallacei ''Doddifoenus wallacei'' is a species of wasp in the family Pelecinellidae. It is the longest known species in the superfamily Chalcidoidea; the female has a length (including ovipositor) of up to 41.4 mm, and its body length ranges from 17.1 to ...

,'' this length includes the

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typica ...

) to merely 0.13 mm long (males of the mymarid ''

Dicopomorpha echmepterygis ''Dicopomorpha echmepterygis'' is the smallest known insect and a species of parasitoid wasp of the family Mymaridae, which exhibits strong sexual dimorphism. The males are blind, apterous, and their body length is only 40% that of females. Wit ...

''). Various lineages have

convergently evolved Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...

features such as enlarged femora, enlarged acropleura, reduced numbers of antennal and tarsal segments, reduced wings or reduced wing venation. Some have significant

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

: male

are "turtle-like fighting machines" that are very different to the females, while males of the aforementioned ''D. echmepterygis'' lack eyes,

ocelli A simple eye or ocellus (sometimes called a pigment pit) is a form of eye or an optical arrangement which has a single lens without the sort of elaborate retina that occurs in most vertebrates. These eyes are called "simple" to distinguish the ...

, mouthparts, antennal flagella or wings.

Ecology

Most chalcidoids are parasitoids, their hosts including

insects Insects (from Latin ') are hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed ...

spiders Spiders (order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species di ...

, ticks and mites,

pseudoscorpions Pseudoscorpions, also known as false scorpions or book scorpions, are small, scorpion-like arachnids belonging to the order Pseudoscorpiones, also known as Pseudoscorpionida or Chelonethida. Pseudoscorpions are generally beneficial to humans bec ...

and even gall-forming

nematodes The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (he ...

. Some species parasitise a wide range of hosts, while others have a narrow host range. They attack host life stages ranging from eggs to adults. The superfamily includes primary, secondary and tertiary parasitoids, both ecto- and endoparasitoids, and both solitary and gregarious parasitoids. There are also herbivorous chalcidoids within the families of

Agaonidae The family Agaonidae is a group of pollinating fig wasps. They spend their larval stage inside the fruits of Ficus, figs. The pollinating wasps (Agaoninae, Kradibiinae, and Tetrapusiinae) are the mutualism (biology), mutualistic partners of the ...

Epichrysomallidae Epichrysomallidae is a family of gall-forming wasps associated with fig trees (genus ''Ficus'') - they make galls in figs, or on leaves or twigs. Once considered a subfamily of Pteromalidae (Epichrysomallinae), this group of genera has been eleva ...

Eurytomidae The Eurytomidae are a family within the superfamily Chalcidoidea. Unlike most chalcidoids, the larvae of many are phytophagous (feeding in stems, seeds, or galls), while others are more typical parasitoids, though even then the hosts are usuall ...

Eulophidae The Eulophidae is a large family of hymenopteran insects, with over 4,300 described species in some 300 genera. The family includes the genus '' Elasmus'', which used to be treated as a separate family, "Elasmidae", and is now treated as a subfa ...

Melanosomellidae Melanosomellidae is a family of parasitic wasps in the superfamily Chalcidoidea Chalcid wasps (, , for their metallic colour) are insects within the superfamily Chalcidoidea, part of the order Hymenoptera. The superfamily contains some 22,5 ...

Ormyridae The Ormyridae are a small family of parasitic wasps in the superfamily Chalcidoidea. They are either parasitoids or hyperparasitoids on gall-forming insects, Asparagobiinae van Noort, Burks, Mitroiu and Rasplus, 2024 *'' Asparagobius'' Mayr, 19 ...

Pteromalidae The Pteromalidae are a large family of wasps, the majority being parasitoids of other insects. They are found throughout the world in virtually all habitats, and many are important as biological control agents. The oldest known fossil is known fr ...

, Tanaostigmatidae and

Torymidae Torymidae is a family of wasps in the superfamily Chalcidoidea. Most species in this family are small with attractive metallic coloration, and females generally have long ovipositors. Many are parasitoids on gall-forming insects, and some are phy ...

. Agaonidae only develop within

figs The fig is the edible fruit of ''Ficus carica'', a species of tree or shrub in the flowering plant family Moraceae, native to the Mediterranean region, together with western and southern Asia. It has been cultivated since ancient times and i ...

. Predation is exhibited by larvae of some

Encyrtidae Encyrtidae is a large family of parasitic wasps, with some 3710 described species in about 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 variab ...

(prey on

coccid Scale insects are small insects of the Order (biology), order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient g ...

eggs) and some Eurytomidae (prey on

Cynipidae Gall wasps, also wikt:gallfly#Usage notes, traditionally called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1 ...

larvae).

Importance

Chalcidoidea is one of the most important taxa of biological control agents. They are used to control pest insects in both natural and agricultural ecosystems. Some herbivorous species are also used in biological control, such as the melanosomellid ''

Trichilogaster acaciaelongifoliae ''Trichilogaster acaciaelongifoliae'' is an Australian bud-galling wasp from the family Pteromalidae that parasitises, among others, ''Acacia longifolia'' (long-leaved wattle, or Sydney golden wattle), which has become an invasive plant, invasiv ...

'' for control of the weed ''

Acacia longifolia ''Acacia longifolia'' is a species of ''Acacia'' native to southeastern Australia, from the extreme southeast of Queensland, eastern New South Wales, eastern and southern Victoria, southeastern South Australia, and Tasmania. Common names for it ...

''. There are also chalcidoids that are agricultural pests themselves, mainly attacking plant seeds. ''

Bruchophagus ''Bruchophagus'' is a genus of wasps belonging to the family Eurytomidae. The genus has cosmopolitan distribution. ''Bruchophagus'' is a genus of small wasps in the family Eurytomidae. These wasps are primarily seed predators, meaning their lar ...

'' attack seeds of legumes (e.g.

alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial plant, perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, ...

), ''Systole'' attack seeds of

Apiaceae Apiaceae () or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus ''Apium,'' and commonly known as the celery, carrot, or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering p ...

used as spices (e.g.

coriander Coriander (), whose leaves are known as cilantro () in the U.S. and parts of Canada, and dhania in parts of South Asia and Africa, is an annual plant, annual herb (''Coriandrum sativum'') in the family Apiaceae. Most people perceive the ...

) and '' Megastigmus'' attack seeds of

Pinaceae The Pinaceae (), or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as Cedrus, cedars, firs, Tsuga, hemlocks, Pinyon_pine, piñons, larches, pines and spruces. The family is incl ...

grown in plantations. Females of family Agaonidae are important as pollinators of figs. Some chalcidoids, especially those in genera ''

Trichogramma ''Trichogramma'' is a genus of minute polyphagous wasps that are endoparasitoids of insect eggs. ''Trichogramma'' is one of around 80 genera from the family Trichogrammatidae, with over 200 species worldwide.Consoli FL, Parra JRP, Zucchi RA (20 ...

'' (

Trichogrammatidae The Trichogrammatidae are a family of small endoparasitoid wasps in the superfamily Chalcidoidea that include some of the smallest of all insects, with most species having adults less than 1 mm in length, with species of '' Megaphragma'' ...

) and '' Nasonia'' (

) are model organisms in scientific research. They have been used to study sex determination, the influence of bacterial

endosymbionts An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Typically the two organisms are in a mutualistic relationship. Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root ...

and the genetics of speciation. The genome of moth parasitoid ''

Copidosoma floridanum ''Copidosoma floridanum'' is a species of wasp in the family Encyrtidae which is primarily a parasitoid of moths in the subfamily Plusiinae. It has the largest recorded brood of any parasitoidal insect, at 3,055 individuals. The life cycle begi ...

'' was sequenced as part of the i5K project.

Taxonomy

Chalcidoidea is a

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

, whose family constituency is in constant flux, as new hypotheses of relationships are constantly being proposed and rejected; with the advent of

molecular systematics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

, it seems that the future will see further revisions of the classification in use today. There are fifty

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

families recognized at present: *

Walker Walker or The Walker may refer to: People *Walker (given name) *Walker (surname) *Walker (Brazilian footballer) (born 1982), Brazilian footballer Places In the United States *Walker, Arizona, in Yavapai County *Walker, Mono County, California * ...

, 1846 *

Aphelinidae The Aphelinidae are a moderate-sized family of tiny parasitic wasps, with about 1100 described species in some 28 genera. These minute insects are challenging to study, as they deteriorate rapidly after death unless extreme care is taken (e.g., ...

Thomson Thomson may refer to: Names * Thomson (surname), a list of people with this name and a description of its origin * Thomson baronets, four baronetcies created for persons with the surname Thomson Businesses and organizations * SGS-Thomson M ...

, 1876 * Azotidae Nikolskaya & Yasnosh, 1966 * Baeomorphidae Yoshimoto, 1975 (formerly Rotoitidae) * Boucekiidae Gibson, 2003 (formerly part of

) * Calesidae Mercet, 1929 (formerly part of

) * Ceidae Boucek, 1961 (formerly part of

) *

Cerocephalidae Cerocephalidae is a small family of chalcid wasps, previously classified as subfamily Cerocephalinae, in the polyphyletic family Pteromalidae. Most species are parasitoids In evolutionary ecology, a parasitoid is an organism that lives in clo ...

Gahan, 1946 (formerly part of

) * Chalcedectidae Ashmead, 1904 (formerly part of

) *

Latreille, 1817 *

Chrysolampidae Chrysolampidae is a small family of parasitoids within the Chalcidoidea. The family is related to a clade that includes the Eucharitidae, Perilampidae and Eutrichosomatidae. This group of wasp families have first-instar larvae that are called " ...

Dalla Torre, 1898 (formerly part of

Perilampidae The Perilampidae are a small family (biology), family within the Chalcidoidea, composed mostly of hyperparasite, hyperparasitoids. The family is closely related to the Eucharitidae, Chrysolampidae, and Eutrichosomatidae. As presently defined, si ...

) * Cleonymidae

, 1837 (formerly part of

) * Coelocybidae Boucek, 1988 (formerly part of

) * Cynipencyrtidae Trjapitzin, 1973 * Diparidae Thomson, 1876 (formerly part of

) *

, 1837 *

Hill & Riek, 1967 (formerly part of

) *

Eucharitidae The Eucharitidae are a family of parasitic wasps. Eucharitid wasps are members of the superfamily Chalcidoidea and consist of four subfamilies: Akapalinae, Eucharitinae, Gollumiellinae, and Oraseminae. Most of the 42 genera and >400 species o ...

Latreille, 1809 *

Westwood, 1829 *

Eunotidae Eunotidae is a family of chalcidoid wasps. In 2022, this family was described based on an analysis of a combination of molecular, morphological, and life history data. Description Small parasitic wasps. Most species are known to be parasitoids ...

Ashmead, 1904 (formerly part of

) *

Eupelmidae Eupelmidae is a family of parasitic wasps in the superfamily Chalcidoidea. The larvae of the majority are primary parasitoids, commonly on beetle larvae, though many other hosts are attacked, including spiders. Details of the life history varies ...

, 1833 *

, 1832 * Eutrichosomatidae Peck, 1951 (formerly part of

) *

Herbertiidae Herbertiidae is a family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, ...

Boucek, 1988 (formerly part of

) * Hetreulophidae Girault, 1915 (formerly part of

) * Heydeniidae Hedqvist, 1961 (formerly part of

) * Idioporidae LaSalle, Polaszek & Noyes, 1997 (formerly part of

) *

Leucospidae The Leucospidae (sometimes incorrectly spelled Leucospididae) are a specialized group of wasps within the superfamily Chalcidoidea, that are ectoparasitoids of aculeata, aculeate wasps or bees. They are typically mimicry, mimics of bees or sting ...

Fabricius Fabricius (, ) is a surname. Notable people with the surname include: *people from the Ancient Roman Fabricia gens, gens Fabricia: **Gaius Fabricius Luscinus, the first of the Fabricii to move to Rome * Johann Goldsmid (1587–1616), known by his ...

, 1775 * Lyciscidae Boucek, 1958 (formerly part of

) * Macromesidae Graham, 1959 (formerly part of

) *

Megastigmidae Megastigmidae is a family of chalcid wasps in the order Hymenoptera. There are about 12 genera and more than 170 described species in Megastigmidae. Megastigmidae was formerly considered a subfamily of the family Torymidae Torymidae is a famil ...

Thomson, 1876 *

Girault, 1913 (formerly part of

) * Metapelmatidae Boucek, 1988 (formerly part of

) * Moranilidae Boucek, 1988 (formerly part of

) *

Mymaridae The Mymaridae, commonly known as fairyflies or fairy wasps, are a family (biology), family of chalcid wasp, chalcidoid wasps found in temperate, subtropical, and tropical regions throughout the world. The family contains around 100 genera with 1, ...

Haliday, 1833 *

Neanastatidae Neanastatidae is a family of chalcid wasps. The genera comprising this family ('' Lambdobregma'' and '' Neanastatus'') were previously placed in the Neanastatinae subfamily of a paraphyletic Eupelmidae Eupelmidae is a family of parasitic wasps ...

Kalina, 1984 (formerly part of

) * Neodiparidae Boucek, 1961 (formerly part of

) * Ooderidae Boucek, 1958 (formerly part of

) *

Förster Förster or Foerster is a German-language, German surname meaning "forester". (It has often been Anglicised as Forster (surname), Forster). Notable people of this name include: Förster * Arnold Förster (1810–1884), a German entomologist * Augus ...

, 1856 *

Pelecinellidae Pelecinellidae is a small family of chalcidoid wasps, formerly treated as the subfamily Leptofoeninae within Pteromalidae. They, like many small chalcidoids, are brilliantly metallic. The subfamily contains three genera; '' Nefoenus'', '' Doddi ...

Ashmead, 1895 (formerly part of

) *

Latreille, 1809 * Pirenidae Haliday, 1844 ( including Eriaporidae) (formerly part of

) *

Dalman, 1820 * Signiphoridae Ashmead, 1880 * Spalangiidae Haliday, 1833 (formerly part of

) *

Systasidae Systasidae is a family (biology), family of Chalcid wasp, chalcidoid wasps. In 2022, this family was described based on an analysis of a combination of molecular, morphological, and life history data. Description Small (body length 0.6–3.0&nbs ...

Boucek, 1988 (formerly part of

) * Tanaostigmatidae Howard, 1890 *

Tetracampidae The Tetracampidae are a small family of parasitic wasps in the superfamily Chalcidoidea. They are parasitoids of phytophagous insects, primarily flies. The 44 species in 15 genera are almost entirely absent from the New World The term "Ne ...

, 1856 *

, 1833 *

Haliday, 1851 There are also three extinct families: *† Diversinitidae Haas, Burks & Krogmann, 2018 *† Khutelchalcididae Rasnitsyn, Basibuyuk & Quicke, 2004 *† Protoitidae Ulmer & Krogmann, 2023 Of these families, at least five are known to be artificial groups (

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

), and have been divided into several families. The most problematic, the Pteromalidae, has recently been split into 24 families, and Eupelmidae into three families.

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 a

* Gibson, G. A. P., Huber, J. T., and J. B. Woolley. 1997. ''Annotated keys to the genera of Nearctic Chalcidoidea (Hymenoptera).'' NRC Research Pres

References

External links

Universal Chalcidoid DatabaseImages of chalcidoids on MorphBank, a biological image database
Pictorial overview. {{Authority control Chalcidoidea, Biological pest control wasps Hymenoptera superfamilies