Chalcid wasp - WikiHQ

thumb|[[Leucospis sp. (Leucospidae)]]

thumb|[[Dicarnosis erythrocephala (Encyrtidae)]]

thumb|[[Eurytoma obtusiventris female, family Eurytomidae]]

thumb|[[Torymus female, family Torymidae]]

thumb|[[Eupelmus vuilleti (Eupelmidae) from Mali]]

Chalcid wasps (, , for their metallic colour) are insects within the superfamily Chalcidoidea, part of the order Hymenoptera. 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, rather than the superfamily as a whole; accordingly, most recent publications (e.g.,

However, the group is morphologically very diverse. Chalcidoids range in size from up to long (females of the pelecinellid Doddifoenus wallacei, this length includes the ovipositor) to merely long (males of the mymarid Dicopomorpha echmepterygis). Various lineages have convergently evolved 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: male fig wasps are "turtle-like fighting machines" that are very different to the females, while males of the aforementioned D. echmepterygis lack eyes, ocelli, mouthparts, antennal flagella or wings.

There are also herbivorous chalcidoids within the families of Agaonidae, Epichrysomallidae, Eurytomidae, Eulophidae, Melanosomellidae, Ormyridae, Pteromalidae, Tanaostigmatidae and Torymidae. Agaonidae only develop within figs.

Predation is exhibited by larvae of some Encyrtidae (prey on coccid eggs) and some Eurytomidae (prey on Cynipidae larvae).

Some chalcidoids, especially those in genera Trichogramma (Trichogrammatidae) and Nasonia (Pteromalidae) are model organisms in scientific research. They have been used to study sex determination, the influence of bacterial endosymbionts and the genetics of speciation.

Taxonomy

Chalcidoidea is a superfamily of Hymenoptera, whose family constituency is in constant flux, as new hypotheses of relationships are constantly being proposed and rejected; with the advent of molecular systematics, recent revisions (post-2020) have substantially revised the classification in use today.

There are fifty extant families recognized at present:

Agaonidae Walker, 1846
Aphelinidae Thomson, 1876
Azotidae Nikolskaya & Yasnosh, 1966 The extinct family Khutelchalcididae was also removed from the superfamily in 2022.