Twisted Leaves And Green Oranges: What Citrus Growers Should Know About The Asian Citrus Psyllid

Posted on: 11 November 2015

From California to Florida, citrus producers are fighting a formidable plant pest and the hideous tree-killing disease this little bug spreads around. Called the Asian citrus psyllid, this tiny, aphid-sized bug is thriving in some U.S. groves, and it's turning oranges into green, mangled mutants.

Here's what citrus farmers need to know:

Who is this grove invader?

The Asian citrus psyllid (ACP), also known as Diaphorina citri, first made its American appearance in 1998 in Florida backyard plants. By 2001, it had spread to Texas, and by 2008 the insect had made its way into Southern California by way of Mexico. It is now found in many Southern states across the nation.

The bugs themselves aren't the issue as much as the bacterium they carry, which they inject into the trees causing huanglongbing disease (HLB), a fatal malady that kills the trees within five years. Once a tree is infected, there is no cure, so citrus growers must be vigilant about protecting their groves and identifying any ACP on their citrus products.

Identifying the ACP and HLB in your plants.

One of the first signs that you may have an ACP infestation is the abnormal curling and twisting of foliage as the ACP feeds on leaves. Many other generally harmless insects can cause leaf curl or twisting, so it's up to growers to inspect any trees showing this symptom to determine which insect or insects is actually causing the damage.

It's important to know what the insects look like. They are only 1/8th in. long as adults, so a magnifying glass is a must when searching for them. They may appear as small thorns because they feed at an upright angle on leaves. Their eggs are yellow, and can often be found on newer leaf growth. As juveniles hatch, they often can be found in a fluffy white mass of waxy tubules as shown in the above link.

It's best to inspect your trees at least once a month, and to keep up with reports of the insects in your region. If you do find the insect, you should contact the USDA and make a report. Your local cooperative extension agent will help you with this process. California growers can locate an agricultural commissioner here.

Steps to mitigate the ACP and HLB.

Sticky traps should be placed in trees, and powerful insecticides may also be necessary. Foliar applications of the pyrethroid beta-cyfluthrin and systemic imidacloprid are two of the agents that are being used to combat this pest.

Growers are also trying to use a process called acoustic disruption. They've installed devices that can hear males calling for mates. The little speakers in the traps respond with fake female calls and lure the males into the trap.

Other steps you should take are keeping your groves mowed and tidy, avoiding grafts from questionable sources, and applying soil drenches of systemic imidacloprid in the summer and fall seasons.

Learn all you can about this crop-destroying pest, and ask your tree service professionals about the eradication methods that have worked for them in your area.

For professional tree care, contact a company such as Sylvester's Tree Service.