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Controlling the Asian Citrus Psyllid Just Got More Difficult?

Citrus greening- also known as Huanglongbing, or HLB- is an exotic disease that is currently prevalent throughout Florida’s citrus industry. This disease is carried by an invasive insect known as the Asian Citrus Psyllid (ACP) and infects citrus trees by being a vector-transmitted pathogen. Citrus greening was first discovered in Florida in 2005 and has since been found in every Florida county with commercial citrus production.

Psyllids on a citrus branch.


In Florida, using insecticides to control the ACP is a major component of greening management strategies. However, according to UF/IFAS entomologist, Dr. Lukasz Stelinski’s latest research, Asian citrus psyllids have become resistant to the only known effective insecticide management for HLB prevention.

What This Means

Resistance reduces the effectiveness of insecticides. It can be behavioral, biochemical, or mediated by more than one mechanism. Frequent use of insecticides to treat pest problems can cause changes in insect populations over time. Because of this, after an insect develops a resistance to an insecticide, it takes more of the insecticide to kill them.

Potential Solutions

We must work diligently in order to combat the ACP’s resistance to insecticides. Dr. Stelinski’s findings indicate rotating insecticides with five different modes of action, can reduce this resistance.

For More Information

HLB-Spreading Psyllids Resistant to Insecticides

For more information on citrus pests and diseases, please visit the UF/IFAS Citrus Agents’ website.


This blog post is written by Natural Resources Extension Program Intern, Ms. Paxton Evans, under supervision by Commercial Citrus Extension Agent, Mr. Chris Oswalt.

3 Comments on “Controlling the Asian Citrus Psyllid Just Got More Difficult?

  1. So after reading the above article seems I have this greening going on. Some leaves have what look like tunnels running through and all the leaves of my tangerine tree are pointing up and slightly curled. They don’t lay flat as most leaves do. Should I destroy the tree and start over? Are there varieties on the market year that are greening resistant. I know UF was working on developing a variety such as this. Thanks.

    • Carol,
      The key for identifying greening is “blotchy mottle” on the leaves. You can find good photos of it in this publication:
      Once you are sure that you have greening, there is no treatment and the tree will continue to decline.
      If you have any other questions, contact our Plant Clinic at (863) 519-1057.

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