Abstract:
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 San-
tis, 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 previ-
ously 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.