Chalcidoidea are one of the most speciose groups of Hymenoptera, with more than 22,00 species described and estimates of 400,000 species worldwide. Economically and ecologically they are among the most important insect control agents. Trichogrammatidae are minute wasps within this complex that parasitize the eggs of numerous Lepidoptera, Heteroptera and other orders of insects. Trichogrammatids are most known for their importance in augmentative biological control programs . They are also important parasitoids of cicadellids, including the glassy-winged sharpshooter (Homoladisca coagulata) and the variegated grape leafhopper (Eryhtroneura variabilis). Within Trichogrammatidae, the tribe Paracentrobiini are known to parasitize eggs of both Miridae and Auchenorrhyncha. Paracentrobiines (the tribe including Paracentrobia) have never been reviewed on a worldwide basis and remain largely unknown. Numerous undescribed species have been encountered as part of sampling for biological control agents for various Heteroptera pests. Because of their small size and unique problems such as tedious slide mounting techniques, poor type collections and general lack of material for study, Trichogrammatidae in general remain understudied. Building upon molecular studies of relationships of the world genera and a morphological based review of the new world genera, current work is focusing on the species of Paracentrobiini and other genera (i.e. Zagella and Oligosita) of economic importance.