Asian Citrus Psyllid and HLB Disease

Asian Citrus Psyllid and HLB Disease

The Asian Citrus Psyllid and the devastating Huanglongbing (HLB) disease the pest spreads to citrus trees are threatening the existence of the citrus industry. All types of citrus are affected by this bacterial disease. The psyllid arrived in Southern California in 2008, and the HLB disease was first detected in Los Angeles in 2012. There is major concern that the disease will spread further into California. HLB poses a threat to both commercial citrus production and residential citrus trees.

Concern for the Citrus Industry:

  • There is no cure once the citrus tree becomes infected with HLB.
  • The diseased citrus tree will decline in health and eventually die in as little as five years.
  • The psyllid can carry the bacterial disease, if infected, from tree to tree, infecting healthy trees along the way.


  • The source of origin of the pest and disease it spreads is thought to be either Asia or India.
  • The psyllid entered Florida and spread throughout the United States rapidly as nursery plants entered commercial groves and as hurricanes shook the state.
  • The psyllid entered California through Mexico.
  • The psyllid has recently been found in Southern California, and infests citrus growing regions of Florida, Louisiana, Mexico, Texas and Hawaii.

The Disease: Huanglongbing (HLB)

  • Also called citrus greening disease and yellow shoot disease.
  • The disease kills citrus trees and there is no cure.
  • Diseased trees produce lopsided, bitter fruit, and eventually die.

The Pest: Asian Citrus Psyllid

  • A small insect, about the size of an aphid.
  • It can spread HLB from tree to tree as it feeds on the stems and leaves of citrus plants.
  • Eggs are laid on young, new growth of citrus, where small, yellowish orange nymphs feed and develop.

The Solution: We All Play a Critical Role

  • Inspect your citrus trees monthly.
  • Do not move citrus plants, plant material or fruit in or out of quarantine areas or across state or international borders.
  • Plant trees from reputable nurseries to avoid the spread of the pest or disease.
  • Use only registered budwood that comes with source documentation when grafting trees.
  • Dry out or double bag plant clippings prior to disposal.

Long-term Citrus Industry Solution

Research is being done in the citrus industry to control the spread and severity of the psyllid. Advancements in trapping, detection and biological controls are under research.
If you suspect that your citrus trees have Asian Citrus Psyllid or HLB disease contact your local Agricultural Commissioner’s office or the CDFA Pest Hotline at (800) 491-1899.