Psyll[ae]

from The Collaborative International Dictionary of English v.0.48

Psylla \Psyl"la\, n.; pl. {Psyll[ae]}. [NL., from Gr. ? a flea.]
   (Zool.)
   Any leaping plant louse of the genus {Psylla}, or family
   {Psyllid[ae]}.
   [1913 Webster]