The Insect: Asian Citrus Psyllid

What is the Asian Citrus Psyllid?

The Asian Citrus Psyllid is an aphid-like insect that feeds on the leaves and stems of citrus trees and other citrus-like plants – but the real danger lies in that it can be a carrier of a deadly, bacterial tree disease called Huanglongbing (HLB) , also known as Citrus Greening Disease.

Where has the insect been found?

The disease-carrying Asian Citrus Psyllid has already caused devastation in Asia, India, parts of the Middle East, and South and Central America.   Now the psyllid has been found in Mexico, Hawaii, Texas, Louisiana, Georgia, Alabama, South Carolina, Florida and – most recently – California.  Diseased trees have only been found in Florida and Louisiana, so far.  In Florida, HLB disease is ravaging the citrus industry, with all 32 counties containing commercial citrus production having HLB.

In June 2008, the psyllid was spotted dangerously close to California – right across the international border in Tijuana, Mexico.  Only a few short months later, it was detected in San Diego and Imperial counties. The Asian Citrus Psyllid has also been intercepted coming into California in packages of fruit and plants, including citrus, ornamentals, herbs and bouquets of cut flowers, shipped from other states and countries.

What is being done to stop the insect?

The California Department of Food and Agriculture has issued a state interior quarantine in areas where the psyllid has been found, and is applying treatments to control the infestation.  County agricultural commissioners, CDFA and USDA, along with industry groups such as the Citrus Research Board, are working together with early detection programs including increased trapping. Additionally, the California Citrus Research Board will be setting up new diagnostic laboratories at several locations in the state to enable mass sampling of psyllids and plant material.

Inspection of cargo at international ports, state lines, airports and mail-sorting facilities has been ramped up to intercept the insect. But don’t forget that consumers play a critical role in helping protect our state from the psyllid and HLB. Live plants or plant parts should never be transported from other states, and people should inspect their citrus trees often.

How could the Asian Citrus Psyllid further spread in our state?

The Asian Citrus Psyllid could spread throughout the state by the transportation of infested plants or plant parts.  To curb this, a quarantine has been implemented.

The disease-carrying Asian Citrus Psyllid could spread throughout the state on citrus plants and close relatives of citrus – such as orange jasmine or Indian curry leaves – that arrive in airplanes, ships, trucks, cars or mail. Distribution of orange jasmine plants by retail nurseries was the main method of movement of the Asian Citrus Psyllid throughout Florida. Floral bouquets containing psyllid-infested orange jasmine have been intercepted coming into California from Mexico.

Additionally, because of its small size, the psyllid can easily get caught in the wind, potentially traveling for miles.

Floral bouquets containing psyllid-infested orange jasmine have been intercepted coming into California from Mexico.

How would the Asian Citrus Psyllid enter our state?

Orange jasmine is a relative of citrus and can be a carrier of the disease-carrying psyllid.

The disease-carrying Asian Citrus Psyllid would be most likely to enter our state on citrus plants and close relatives of citrus – such as orange jasmine or curry leaves – that arrive in airplanes, ships, trucks, cars or mail. Distribution of orange jasmine plants by retail nurseries was the main method of movement of the Asian Citrus Psyllid throughout Florida. Floral bouquets containing psyllid-infested orange jasmine have been intercepted coming into California from Mexico.

Curry leaves – which can be a carrier of the psyllid - have carried the insect from Hawaii to California. To date, the psyllids have been intercepted and destroyed.

Infested plants or plant parts may also unknowingly be transported by homeowners.

With the psyllid’s recent detection in Mexico, there is a real possibility that the psyllid will fly north. Because of its small size, the psyllid can easily get caught in wind, potentially traveling for miles.