Psylla is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of sap-sucking insect belonging to the order of hemiptera

Hemiptera

Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...

. There are 12 species within the genus, each with a specific host

Host (biology)

In biology, a host is an organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter. In botany, a host plant is one that supplies food resources and substrate for certain insects or other fauna...

. Some harmful species commonly known as flies belong to neighbouring genera such as Cacopsylla (which includes most of the pyslla harmful to fruit trees), the Albizia fly (Acizzia Jamatonica, from the Psyllidae family) and the laurel fly (Trioza alacris).

Species

• Psylla alni, preys on alder
  Alder
  Alder is the common name of a genus of flowering plants belonging to the birch family . The genus comprises about 30 species of monoecious trees and shrubs, few reaching large size, distributed throughout the North Temperate Zone and in the Americas along the Andes southwards to...
  
  s
• Psylla alpina,
• Psylla betulae, preys on birch
  Birch
  Birch is a tree or shrub of the genus Betula , in the family Betulaceae, closely related to the beech/oak family, Fagaceae. The Betula genus contains 30–60 known taxa...
  
  es
• Psylla betulaenanae,
• Psylla buxi, preys on buxus
  Buxus
  Buxus is a genus of about 70 species in the family Buxaceae. Common names include box or boxwood ....
  
  
• Psylla cordata, preys on tilia
  Tilia
  Tilia is a genus of about 30 species of trees native throughout most of the temperate Northern Hemisphere. The greatest species diversity is found in Asia, and the genus also occurs in Europe and eastern North America, but not western North America...
  
  
• Psylla fusca
• Psylla pyri
  Psylla pyri
  Psylla pyri is one of the most important pear phytophagics; because of the numerous chemical interventions, its dangerousness is increased, reducing the phytopathogenics's populations of this bug...
  
  , preys on European Pear
  European Pear
  The European Pear, Pyrus communis, is a species of pear native to central and eastern Europe and southwest Asia. The European Pear is one of the most important fruits of temperate regions, being the species from which most orchard pear cultivars grown in Europe, North America and Australia have...
  
  trees