The Coastal Gardener:

By now, you may have heard about a new pest that was discovered last month in Orange County. The tiny insect poses a very serious threat to California’s $1.6-billion citrus industry, as well as to the thousands of us who grow citrus in our gardens.

Last month, state agricultural officials trapped five adult Asian citrus psyllids on a lemon tree growing in a Santa Ana garden. The discovery has triggered alarm throughout the state and caused some home citrus gardeners to worry.

Because of the discovery, the California Department of Food and Agriculture on Aug. 28 placed all of Orange County under a quarantine that now regulates the movement of citrus fruits and plants.

Psyllids (pronounced sillids) have also been discovered in parts of Los Angeles, Riverside, Imperial and San Diego counties, with quarantines also in place in these areas as well.

What is this new pest, and what does it mean?

Asian citrus psyllids are tiny insects, no bigger than an eighth of an inch — about the size of most aphids, to which they are closely related.

You’ll likely never see one, but this little sucking insect is only part of the problem anyway. The dilemma is that these little guys have the ability to carry and transmit a very fatal citrus disease.

Citrus greening disease is a bacterial ailment and one of the world’s most feared citrus pathogens. Also called Huanglongbing (meaning yellow dragon in Chinese), it ruins the taste of the fruit and the juice before eventually killing the plants. There is no cure or method for treating a plant once it is infected. The bacterial disease is transmitted to healthy trees exclusively by the Asian citrus psyllid after feeding upon an infected tree.

The good news is that, although the insect is present in a few locations in California, the disease is no closer than Louisiana or Mexico’s Yucatan Peninsula.

But citrus greening disease has already ravaged groves in Florida and wiped out much of the citrus industries in China, India, Saudi Arabia, Egypt and Brazil.

Louisiana and the Yucatan sound like a long way away, but not really. Experts believe the disease will first turn up on a backyard tree, not at a commercial grove.

That’s what happened in Florida, and with the help of the psyllid, soon the entire state was plagued by the disease.

If an infected tree is found, it needs to be removed immediately, before it can be used as a reservoir to spread the disease around the state.

In Santa Ana, the California Department of Food and Agriculture is setting 100 traps per square mile in the area where the psyllids were found and 50 traps per square mile in an additional eight square miles.

What can you do? First, obey the citrus quarantine. Don’t move homegrown citrus fruits, plants or foliage.

Consume all your homegrown citrus fruit at home. That means not packing oranges for a work lunch and not giving a few to relatives and friends to take home with them.

Second, cooperate with agricultural regulations involving the shipping or receiving of fruits and vegetables.

California had a close call last month at a Fresno FedEx depot. An inspection dog found a package of curry leaves containing live Asian citrus psyllids in a bag from India. Tests revealed that the psyllids were infected with the citrus greening disease.

If the psyllids had not been detected, this could have become the launch of the disease in California.

Finally, don’t panic. Don’t cut your lemon tree down and don’t begin spraying insecticides aimlessly.

If you look carefully at your backyard citrus, you’ll likely find numerous pests, including citrus leaf miner, whitefly, scale and others that you didn’t even know were there. These aren’t Asian citrus psyllids.

To learn more about this particular insect and citrus greening disease, visit www.cdfa.ca.gov/phpps/ acp/index.html.

Ask Ron

Question: When can I plant my sweet pea seeds if I want to get early flowers?

Lynn

Costa Mesa

Answer: I usually consider Labor Day as the official beginning of the sweet pea planting season, but in Orange County, you can plant seeds successfully as late as January and started plants even later. If you want the earliest blooms, however, maybe even by Christmas, look for varieties with elegance in their names and plant right away. If you are planting several feet of sweet peas, I suggest blending the elegance varieties 50-50 with other main-season choices for the best show.

ASK RON your toughest gardening questions, and the expert nursery staff at Roger’s Gardens will come up with an answer. Please include your name, phone number and city, and limit queries to 30 words or fewer. E-mail [email protected], or write to Plant Talk at Roger’s Gardens, 2301 San Joaquin Hills Road, Corona del Mar, CA 92625.

RON VANDERHOFF is the Nursery Manager at Roger’s Gardens, Corona del Mar.