Key to species of Phenacoccus Cockerell
1 Multilocular disc pores present on dorsum.................................................................. 2
- Multilocular disc pores absent from dorsum................................................................. 6
2 Dorsal multilocular disc pores numerous, present on head, thorax and across posterior edges of abdominal segments.............................................................................................. hordei (Lindeman)
- Dorsal multilocular disc pores few, on posterior edges of posterior abdominal segments only.......................... 3
3 Circulus present. Some dorsal setae with 1 or 2 trilocular pores next to setal collars................ salviacus Moghaddam
- Circulus absent. Dorsal setae apparently without trilocular pores next to setal collars................................ 4
4 Cerarii present on head................................................................................. 5
- Cerarii absent on head............................................................ arthrophyti Archangelskaya
5 Quinquelocular pores present on venter...................................................... betae Moghaddam
- Quiquelocular pores absent from venter..................................................... pumilus Kiritshenko
6 Dorsal oral collar ducts present........................................................................... 7
- Dorsal oral collar ducts absent.................................................................. solani Ferris
7 Cerarii present medially and submedially on dorsum................................... karkasicus Moghaddam sp. n.
- Cerarii absent medially and submedially from dorsum........................................................ 8
8 Dorsal oral collar ducts present in more or less rows across most segments........................................ 9
- Dorsal oral collar ducts few on posterior abdominal segments only................................ solenopsis Tinsley
9 Circulus numbering 2 or 3.................................................................. aceris (Signoret)
- Circulus numbering 1................................................................................. 10
10 Dorsal oral collar ducts present in 2 or 3 rows.......................................... iranica Moghaddam sp. n.
- Dorsal oral collar ducts present in 1 row.................................................. perillustris Borchsenius