The genus Etiennea Matile-Ferrero is synonymized with Hemilecanium Newstead (Hemiptera: Coccidae). We base this decision on a morphological comparative study of adult females, adult males and first-instar nymphs (crawlers), including a phylogenetic analysis. We recovered a sister group relationship between the type species of the two genera, Etiennea villiersi Matile-Ferrero and Hemilecanium theobromae Newstead; that is, each was more closely related to the other than either was to other species in their respective genera. All species hitherto included in Etiennea are transferred to Hemilecanium: H. bursera (Hodgson & Kondo) comb. nov., H. cacao (Hodgson) comb. nov., H. candelabra (Hodgson) comb. nov., H. capensis (Hodgson) comb. nov., H. carpenteri (Newstead) comb. nov., H. cephalomeatus (Hodgson) comb. nov., H. combreti (Hodgson) comb. nov., H. ferina (De Lotto) comb. nov., H. ferox (Newstead) comb. nov., H. gouligouli (Hodgson) comb. nov., H. halli (Hodgson) comb. nov., H. kellyi (Brain) comb. nov., H. madagascariensis (Hodgson) comb. nov., H. montrichardiae (Newstead) comb. nov., H. multituberculum (Hodgson) comb. nov., H. petasus (Hodgson) comb. nov., H. sinetuberculum (Hodgson) comb. nov., H. tafoensis (Hodgson) comb. nov., H. ulcusculum (Hodgson) comb. nov., and H. villiersi (Matile-Ferrero) comb. nov. Keys to the adult females of all 26 species and known adult males and first-instar nymphs are provided. The adult males and first-instar nymphs of H. theobromae Newstead and E. villiersi Matile-Ferrero are for the first time fully described and illustrated. One new potential pest species of Hemilecanium, H. uesatoi Kondo & Hardy sp. nov., which was collected on three islands of the Ryukyu Archipelago, Japan, is described and illustrated based on the adult female, adult male and first-instar nymph. We discuss evidence that H. uesatoi is a new introduction to the Ryukyu Archipelago. The first-instar nymphs of Hemilecanium can be divided into two distinct morphological groups, the petasus group and the theobromae group. [ABSTRACT FROM AUTHOR]