PROC. ENTOMOL. SOC. WASH. 86(3), 1984, pp. 555-562 SYNOPSIS OF NEARCTIC AZOTINAE (HYMENOPTERA: APHELINIDAE) D. Christopher Darling' and Norman F. Johnson (DCD) Department of Entomology, Cornell University, Ithaca, New York 14853; (NFJ) Department of Entomology, 1735 Neil Avenue, The Ohio State University, Columbus, Ohio 43210. Abstract. — Four species of the Azotinae (Hymenoptera: Aphelinidae) have been described from the Nearctic: Ablerus c/isiocampae (Ashmcad); Azotus perspeciosus (Girault); Azotus americanus (Girault), 1916 new combination; and Azotus dozieri new name for Azotus americanus Dozier, 1928. A lectotype is designated for Azotus perspeciosus. The original rearing record of Ablerus clisiocampae from the eggs of Malacosoma americanum (F.) (Lepidoptcra: Lasiocampidae) is confirmed; the host range of this species also includes armored scale insects (Homoptera: Diaspididae). The presence of Azotus atomon (Walker) in the Nearctic is unsub-stantiated. Yasnosh (1976) has proposed a reclassification of the Aphelinidae (Hymenop-tera: Chalcidoidea) which recognizes seven subfamilies: Aphelininae, Aphytinae, Azotinae, Calesinae, Coccophaginae, Physcinae and Prospaltellinae. The subfam-ily Azotinae is a small group, with only 82 described species. According to Yasnosh (1973), species are secondary parasitoids attacking Diaspididae, Coccidae, Aleu-rodidae (Homoptera), and are also known to emerge from the eggs of Cicadellidae (Homoptera) and Lepidoptera. Hayat (1983) has recently published a key that can be used to identify genera of the subfamily. In this paper we bring together published information on the taxonomy of Nearctic Azotinae, document nomen-clatorial changes and discuss the host associations of Ablerus clisiocampae (Ash-mead). Azotinae Azotinae Nikofskaya 1966, in Nikol'skaya and Yasnosh 1966: 232. Azotinae: Yasnosh, 1976: 167. Diagnosis: antennae 7-merous; third flagellomere short, ringlike in male; clava unsegmented; pronotum entire; prepectus consisting of 2 separate sclerites; fore wings sparsely pubescent; with elongate radial vein and marginal fringe; abdominal tergites 9 and 10 separated; sternite 7 trapeziform, nearly reaching apex of ab-domen; male genitalia with short, broad phallobase; basal ring present; parameres and digiti absent (Yasnosh, 1976). ' Present address: Department of Entomology, Oregon State University, Corvallis, Oregon 97331.