An insect that can spread a citrus-killing disease has been detected in Lake Elsinore, Canyon Lake and surrounding areas, which has prompted the California Department of Food and Agriculture to expand an emergency program to eradicate the pest.

The insect known as Asian Citrus Psyllid can transmit the disease Huanglongbing, "the most devastating disease to citrus in the world," when it feeds on the plants’ leaves and stems, according to the CDFA. "Symptoms of HLB include yellow shoots, small upright leaves, fruit that does not fully color and lopsided fruit with bitter flavor," the state agency advised.

The psyllid has been detected locally in Lake Elsinore, Canyon Lake, Menifee and Romoland, according to Kayla Williams, spokeswoman for State Sen. Bill Emmerson (R-Hemet). The senator, who represents Lake Elsinore and Canyon Lake, sent out an advisory on the state’s emergency program Tuesday.

In addition, the insect "has been detected in many areas in Southern California – Riverside, Imperial, San Diego and Los Angeles counties, primarily," said CDFA spokesman Steve Lyle.

"CDFA is working to control the spread of the pest to the greatest degree possible so that when HLB is introduced -- and it’s when, not if -- there is the best chance to limit damage to citrus. HLB is fatal to citrus trees. There no cure,” Lyle said. “The threat is real and profound – not just to commercial citrus, but to the many, many residential citrus trees in California."

"As the top citrus-producing state in the nation, California's citrus industry has a $1.8 billion impact on our state’s economy," Emmerson said in his advisory. "It's crucial that we act immediately to protect Riverside County from the devastating effect of this pest on our local economy as well as our environment."

For more information about the Asian Citrus Psyllid and the disease Huanglongbing, visit the CDFA’s ACP site. --Toni McAllister contributed to this report.