Chalcid, common name for any of a large group of parasitic insects, also called chalcid wasp or chalcidfly. Tens of thousands of species exist throughout the world, many of which have not been classified. Typical species rarely measure more than 2.5 mm (more than 0.1 in) in length. These include the smallest known insects, the fairy wasps, which are parasites of insect eggs. Other well-known groups are the fig wasps, the only pollinators of some fig species, and the seed chalcids, whose larvae burrow in seeds. Chalcids are characterized by elbowed antennae and greatly reduced wing venation. The larvae of most species are parasitic on the eggs, larvae, or pupae of other insects, although a few are plant eaters. Because so many of their hosts are insects destructive to plants, chalcids are beneficial economically. They prey on asparagus beetles, gall wasps, scale insects, cicadas, Hessian flies, cabbage butterflies, and other pests. Many species are raised in laboratories and released for the biological control of such injurious insects.
Scientific classification: Chalcids make up the superfamily Chalcidoidea, order Hymenoptera. There are between one and two dozen families. Fig wasps make up the family Agaonidae; seed chalcids are in the family Chalcididae.