After the closely related Ichneumonidae, braconids make up the second-largest family in the order Hymenoptera, with about 17,000 recognized species and many thousands more undescribed.

[1] The Braconidae are currently divided into about 47 subfamilies and over 1000 genera,[2] which include Aerophilus, Aleiodes, Apanteles, Asobara, Bracon, Cenocoelius, Chaenusa, Chorebus, Cotesia, Dacnusa, Diachasma, Dimeris, Microgaster, Opius, Parapanteles, Phaenocarpa, Spathius, and Syntretus.

They are often black-brown (sometimes with reddish markings), though some species exhibit striking coloration and patterns, being parts of Müllerian mimicry complexes.

Species that parasitize microlepidopterans, for instance, have longer ovipositors, presumably to reach the caterpillar through layers of plant tissue.

Some wasps also have long ovipositors to bypass caterpillar defense mechanisms such as spines or hairs, or to reach deeply-burrowed Coleoptera larvae in tree trunks.

Some species of braconids are parasitoids of Ostrinia furnacalis (the Asian corn borer, a lepidopteran moth known for being a pest of maize in East Asia), the African sugarcane borer (a moth commonly found in sub-Saharan Africa),[10] the butterfly Danaus chrysippus in Ghana,[11] and Liriomyza trifolii (the American serpentine leafminer) and Manduca quinquemaculata (the tomato hornworm) in North America.

The DNA of the wasp actually contains portions that are the templates for the components of the viral particles and they are assembled in an organ in the female's abdomen known as the calyx.

It underwent extensive diversification from mid or late Cretaceous to early Cenozoic, correlating with the radiation of flowering plants and associated insect herbivores, the main hosts of braconids.

73 individual Braconid fossils of the Königsberg Amber Collection were destroyed during World War II as they were "stored in a salt-mine about 40 km from Göttingen" with petrol.

[18] The species Microplitis croceipes possesses an extremely accurate sense of smell and can be trained for use in narcotics and explosives detection.