The discovery of European gypsy moths in a trap has prompted the California Department of Food and Agriculture to established a quarantine of about 5 square miles in the Ojai area of Ventura County.

State and county inspectors are working closely with residents, growers, landscapers and related businesses in the area to monitor and contain an infestation of the arboreal pest.

Gypsy moth caterpillars feed on hundreds of kinds of plants and are capable of defoliating trees at an alarming rate.

Meanwhile, the Oregon Department of Agriculture has trapped 12 gypsy moths in the state this season and will continue to monitor the situation. Department officials have not ruled out spraying next year if more moths are trapped, according to a department news release.

Four gypsy moths were trapped in Ojai in June 2007, triggering an intensive visual survey and heightened trapping program. Seven more moths were trapped this summer, confirming that Ojai has an actively reproducing infestation, according to the California Department of Food and Agriculture.

Visual surveys this fall revealed egg masses and larval cast skins on and near a property where a camping trailer had recently been parked after coming from an infested area of the Northeast.

Gypsy moths are known to deposit their egg masses on vehicles and outdoor equipment as well as on trees, buildings and other surfaces.

A single gypsy moth caterpillar can eat up to 1 square foot of leaves per day.

In the northeastern United States, where this pest arrived from Europe in the late 1800s, millions of caterpillars emerge each spring and devour large swaths of forest and foliage.

When trees are repeatedly defoliated, they are rendered more susceptible to other pests and diseases, possibly leading to tree death and an increased potential for fire and erosion.

Inspectors have begun contacting residents and businesses in the quarantine area to notify them of the requirements and explain the specific rules for moving plants, yard waste, recreational vehicles and other objects that may harbor gypsy moth egg masses or other life stages of the insect.

A map of the quarantine area is available online at

Gypsy moths in Oregon
Gypsy moth trapping in Oregon officially ended this year with a final tally of 12 gypsy moths detected statewide—the same number of catches as last year.

Most were detected in a residential area of Eugene, which could lead to a proposed project next spring to eradicate the pest.

The dozen of trappings this year is a far cry from the mid-1980s, when more than 19,000 gypsy moths were trapped in Lane County alone.

“Twelve moths doesn't sound like very many when you compare it to the hundreds of thousands of gypsy moths found in the eastern part of the U.S.,” says Helmuth Rogg, supervisor of the Oregon Department of Agriculture’s Insect Pest Prevention and Management Program in Salem. “But we still want to keep the gypsy moth out of Oregon and protect our beautiful state.”

Every year during late spring, Oregon Department of Agriculture trappers place the bright orange or green tent-like traps throughout the state. This year, more than 18,000 traps were placed, inspected and now taken down.

Of the 12 gypsy moths trapped in Oregon this year, seven were found in a residential neighborhood of south Eugene. Three gypsy moths were recovered from separate traps located in the Portland area and are considered unrelated to each other. Two gypsy moths were trapped on the grounds of a rural fire station in Lane County 3 miles southwest of Eugene and are also considered a separate introduction unrelated to the detections in Eugene.

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