RIVERSIDE – Riverside County Agricultural Commissioner Ruben Arroyo will hold a public meeting today to spotlight the potential danger of “citrus greening disease” and how residents can help stop it before it affects the county’s $187 million-per-year commercial citrus crops.
“This disease threatens all citrus trees, whether they are grown by citrus farmers or in residents’ backyards,” Arroyo said. “If you have citrus trees in your yard, make sure you know the symptoms of the disease and please contact county or state officials immediately if you see symptoms.”
Early last week, tests performed on a grapefruit tree on a property near the intersection of Chicago and Marlborough avenues in east Riverside showed that huanglongbing – better known as citrus greening disease – had taken root.
The California Department of Food & Agriculture, in partnership with the U.S. Department of Agriculture, initiated a survey and treatment program to prevent the disease’s spread.
The culprit is a pest known as the Asian citrus psyllid, a finger-tip size, moth-like insect that made its U.S. debut in Florida nearly 20 years ago.
The infected tree was removed, but Arroyo said sticky card traps at the site revealed the presence of psyllids. He said a quarantine is in place covering a five-mile radius from where the diseased tree was uprooted.
On Wednesday, Arroyo and other agricultural officials will host a 5 p.m. meeting in the lobby of the County Administrative Center in downtown Riverside to update residents on strategies to combat the psyllids and how micro and large citrus growers can assist.
The county’s roughly 20,000 acres of commercial citrus crops – oranges, lemons, grapefruit and tangerines – yield about $187 million a year, and citrus greening disease poses a direct threat, according to agricultural officials.
Psyllids originate in tropical and subtropical regions, including South America and south Asia. They first appeared in California in 2008 and have been trapped in citrus-growing areas throughout the Inland Empire, as well as Los Angeles, San Diego and Ventura counties.
Psyllids host a virulent bacteria that can devastate plants’ vascular systems. The greening disease rampaged throughout Florida in 2005 and has inflicted an estimated $3 billion damage to crops in the Sunshine State, according to a study published by the University of Florida.
The U.S. Department of Agricultural said Florida’s citrus crops are likely to produce 70 percent less this year compared to 20 years as a direct result of greening disease. Crops are predicted to yield 14 percent less than in 2016.
The first signs of citrus greening disease are yellowing leaves on trees and fruit that remains green because it never ripens, according to Arroyo.
Different methods are used to combat psyllids. In 2011, the UC Riverside Center for Invasive Species Research began releasing Tamarixia radiata – tiny stinger-less wasps – in the campus’s botanical gardens to keep psyllids out. The wasps lay eggs in psyllid nymphs, on which the wasp larvae feed, killing them.
A university has researcher has received grant funds totaling $4 million to enhance methods of combating the psyllids, according to Arroyo.
Anyone with questions or concerns about huanglongbing and the threat posed by psyllids should contact either the agricultural commissioner’s office at (951) 955-3045, or the state’s pest hotline, (800) 491-1899.