PROC. ENTOMOL. SOC. WASH. 79(3), pp. 367-376 NOTES ON THE SPECIES OF NEORHIZOECUS HAMBLETON, A SYNONYM OF RHIZOECUS KUNCKEL D'HERCULAIS (HOMOPTERA: PSEUDOCOCCIDAE) Edson J. Hambleton Abstract. — Notes and illustrations are given on the five species of Rhi-zoecus previously included in Neorhizoecus together with diagnostic species characters, hosts, and distribution records. In 1946, I published a description of the genus Neorhizoecus to accommo-date four neotropical species that closely resembled Rhizoeciis Kiinckel d'Herculais. The diagnostic features of Neorhizoecus are its oval body shape, 5-segmented antennae, short setose digitules, absence of eyes and tubular cerores. Williams (1970) described a fifth species N. epicopus from Barbados and Trinidad with tritubular cerores, and noted that these structures were also present on N. coffeae (Laing), the type-species. After verifying these observations, I located a single ceroris in each of two para-types of N. setosus Hambleton. Examination of 56 additional specimens of N. setosus from Colombia and Peru indicated as many as 10 cerores on a single specimen, the Colombian specimens each averaged 4-5 cerores, and those from Peru 7-8. The presence of cerores in three of the five species of Neorhizoecus and the intraspecific variation in these structures clearly eliminates the "ab-sence of cerores" as a usable diagnostic character for the genus. The re-maining features which characterize Neorhizoecus also lose their sig-nificance because they are equally applicable to Rhizoecus. For example, of the 52 recognizable American species of Rhizoecus, five have 5-seg-mented antennae, 26 have short, setose digitules, and six have no eyes. Consequently Neorhizoecus coffeae should be returned to RJiizoecus; Neo-rhizoecus setosus and N. epicopus, by virtue of their having cerores, should be placed in Rhizoecus. Although Neorhizoecus andensis Ham-bleton and N. colomhiensis Hambleton have no cerores, it would seem logical for the time being to place them in Rhizoecus because their other characters agree generically. The inclusion of the five Neorhizoecus taxa in Rhizoecus should broaden its composition and facilitate placement of some intermediate fonns with characteristics of both Neorhizoecus and Rhizoecus. I therefore propose that the name Neorhizoecus be synonymized with Rhizoecus, and new name combinations be given accordingly. Genus Rhizoecus Kiinckel d'Herculais Rhizoecus Kiinckel d'Herculais, 1878:163. Type-species: Rhizoecus fal-cifer Kiinckel d'Herculais.