Eulophidae of Costa Rica (Hymenoptera:Chalcidoidea), 4, The genus Closterocerus Westwood s.str. (Hymenoptera: Eulophidae)

The Neotropical species of Closterocerus Westwood are revised using morphological data. Sixty-six species are included, of which 60 are described as new, and 45 species are newly recorded from Costa Rica. Four of the previously described species, C. coffeellae Ihering, C. flavicinctus De Santis, C. pulcher (Howard), C. purpureus (Howard), were previously recorded from the Neotropical region, while the remaining two, C. cincinnatus Girault and C. cinctipennis Ashmead, were previously recorded from the Nearctic region but not from the Neotropics. Hosts are known for five of the species, which are all targeting leafmining insects (Coleoptera, Diptera, Lepidoptera). A key for the identification of the Neotropical species is included