Field characters

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.

Validation characters

Clusters of ventral multiloculars and oral-collar tubular ducts present along body margin of thorax and head; some dorsal conical setae with basal clusters of trilocular pores, with 2 or 3 dorsomedial cerarii; circulus normally present, oval, not divided by intersegmental line, sometimes absent; dorsal oral-collar tubular ducts and multilocular pores scattered over surface; quinquelocular pores on ventromedial areas of thorax and anterior abdominal segments; translucent pores apparently absent; 18 pairs of cerarii.


Phenacoccus stelli is similar to P. gossypii by having dorsal oral collars and multiloculars on the thorax and abdomen, 18 pairs of cerarii, and ventral quinquelocular pores. Phenacoccus stelli can be distinguished (characters of P. gossypii are in parentheses) by having circulus small (large), ventral quinquelocular pores restricted to thorax and anterior abdominal segments (scattered over venter), marginal clusters of ventral oral-collar tubular ducts and multilocular pores along body margin (distinct clusters absent), dorsomedial cerarii on 1 or 2 posterior abdominal segments (absent posteriorly).

U.S. quarantine notes

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).

Important references

Brain1915; DeLott1958a; DeLott1974

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