See text Chalcid wasps (/ˈkælsɪd/, from Greek khalkos 'copper', for their metallic colour)[1] are insects within the superfamily Chalcidoidea, part of the order Hymenoptera.

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.

[2] Most chalcidoids are parasitoids, their hosts including insects, spiders, ticks and mites, pseudoscorpions and even gall-forming nematodes.

[2][5] There are also herbivorous chalcidoids within the families of Agaonidae, Epichrysomallidae, Eurytomidae, Eulophidae, Melanosomellidae, Ormyridae, Pteromalidae, Tanaostigmatidae and Torymidae.

[7] 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.