Definition of pear sucker in US English:

pear sucker

noun

  • A psyllid bug of European origin, Cacopsylla (or Psylla) pyricola, a major pest of pear trees which it damages in several ways, especially by feeding on sap and producing excessive honeydew which encourages the growth of certain moulds.

Origin

Late 19th century; earliest use found in Eleanor Anne Ormerod (1828–1901), economic entomologist.