Body oval, canary yellow; body covered by layer of white mealy wax; ovisac probably covers body and is almost spherical; with 17 or 18 pairs of short lateral filaments, becoming progressively longer posteriorly, caudal pair short but longer than the rest. Occurring on petioles near base of leaf.
This species was intercepted at U. S. ports-of-entry 12 times between 1995 and 2012, with specimens originating from The Netherlands and South Africa. We also have examined specimens taken in quarantine from The Netherlands (Leucodendron, Ornithogalum, Symporicarpos); South Africa (Berzelia, Erica, Leucodendron, Roella). ScaleNet lists hosts in Fabaceae and Proteaceae. It is most commonly intercepted on species of the latter (Leucadendron), and also on Berzelia and Brunia (Bruniaceae). ScaleNet distribution records for P. stelli include South Africa only. Several species of Phenacoccus other than P. defectus Ferris, P. franseriae Ferris, P. gossypii Townsend & Cockerell, P. hakeae Williams, P. helianthi (Cockerell), P. madeirensis Green, P. parvus Morrison, P. solani Ferris, P. solenopsis Tinsley and P. stelli (Brain) have been taken at U. S. ports-of-entry including: P. alleni McKenzie (Mexico, on Artemisia); P. avenae Borchsenius (Turkey, on Stachys); P. azaleae Kuwana (Japan, on azalea); P. graminicola Leonardi (New Zealand, on Feijoa); P. hurdi McKenzie (Mexico, on Dendranthema and Capsicum); P. indicus Avasthi & Shafee (Thailand, on Euphorbia); P. multicerarii Granara de Willink (Mexico, on unknown host); P. manihoti Matile-Ferrero (Central Africa and South America, on Manihot); P. nephelii Takahashi (Thailand, on Garcinia; Vietnam, on Nephelium); P. pergandei Cockerell (Japan and Korea, on Diospyros, Magnolia, Malus, Prunus, Punica, and Rhododendron); and P. persimplex Borchsenius (Kazakhstan, on Malus).