Introduction of a biological predator is one of the methods being considered to control the spread of the slow-migrating avocado lace bugs that have infested backyard groves in southern San Diego County since August.

The idea was noted in a draft plan put forth during a meeting Monday in San Diego among representatives of the state and county agriculture departments, industry leaders and researchers from state universities.

A final plan to control the avocado lace bug could be completed within the next two or three weeks, said Steve Lyle, spokesman of the California Department of Food and Agriculture. Lyle said his agency is awaiting feedback from the San Diego County agriculture commission, researchers from the University of California, and the California Avocado Commission —— the research and promotions arm of the industry.

"Based on our experience with situations like this, it appears unlikely that we can eradicate the pest," Lyle said. "We will seek to control the population of the avocado lace bug and keep it away from commercial production areas. We are looking at an integrated approach that could involve some treatments and biological measures in support of this treatment."

To date, the leaf-eating avocado lace bug has not migrated any farther north than Highway 52 in San Diego, according to the San Diego County Commission of Agriculture, Weights, and Measures. A buffer zone where there are no avocado trees exists just beyond the Lake Murray area. The pest has not been found in any other avocado-producing California counties, according to David Kellum, entomologist with the county agriculture commission.

But the pests could reach North County groves if transported in host material, Kellum added.

Meanwhile, the state department of food and agriculture is proposing that parasitoids be considered as a bio-control on the avocado lace bug. One of those parasitoids, the microscopic stingerless wasp, feeds on avocado lace bug eggs, Lyle said.

Previously, San Diego County Commissioner of Agriculture Kathleen Thuner asked the state to give the avocado lace bug a permanent California Pest Rating of "A," which suggests an urgent problem. Right now, the rating is "Q," meaning there is quarantine potential, but the economic impact is undetermined.

"We are still asking for the "A" rating and a quarantine," Kellum said after the meeting Monday. "That will give us more regulatory teeth in controlling the movement of host materials from nurseries out of Southern San Diego County."

The 250-square-mile infested area in southern San Diego County falls between Interstate 8 and Highway 52 to the north, along the U.S.-Mexico border to the south, and San Diego Bay east to about El Cajon, according to Kellum.

Lyle said an "A" rating and a quarantine are not in the draft plan right now, though both are still being considered.

With the avocado lace bug eating parts of the leaves, the fruit is exposed to direct sun, stunting the fruits growth or causing other damage.

The pest is normally found in tropical, humid climates. Not much more is known about the avocado lace bug, or how it got into the United States.

Contact staff writer Lorell Fleming at (760) 731-5798 or lfleming@nctimes.com.