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Stink bug sighted in Stanislaus could harm area crops

Above, the eggs of a brown marmorated stink bug are found on the back of a Chinese pistache leaf in midtown Sacramento in September 2013. The pest, shown on a tree branch at left, harms many fruit and vegetable crops.
Above, the eggs of a brown marmorated stink bug are found on the back of a Chinese pistache leaf in midtown Sacramento in September 2013. The pest, shown on a tree branch at left, harms many fruit and vegetable crops.

Stanislaus County has reported its first two sightings of the brown marmorated stink bug, which has done major damage to crops and gardens in the eastern United States.

The pest harms many fruit and vegetable crops and also might pose a threat to the county’s more extensive plantings of almonds and walnuts, said Jhalendra Rijal, an entomologist with the Modesto-area office of the University of California Cooperative Extension.

The first sighting was last month outside a business at Kansas Avenue and Highway 99 in Modesto, reported by the owner. The other was outside the home of a pest-control adviser in Turlock. Rijal said no bugs have been reported in the county’s farmland – including peaches, wine grapes, apples and other high-risk crops – but they could be out there.

“There is definitely potential for this pest, because it can feed on many host plants in agricultural and urban settings,” he said.

The species is from eastern Asia. Its first U.S. sighting was in Allentown, Pa., in 1998, apparently the result of an accidental shipment. Since then, it has taken a heavy toll on fruit and vegetable growers from Pennsylvania to North Carolina.

“The damage they do to fruit is horrendous,” Pennsylvania peach grower Tom Haas told The Associated Press after losing about 40 percent of his crop in 2011. The pest has a needlelike mouth that pierces the skin of fruits and vegetables, leaving them pockmarked and discolored.

The bug also has been detected in Stockton and in cities or rural areas in Sacramento, Yolo, Sutter, Butte, Santa Clara and Los Angeles counties. The highly urban midtown district of Sacramento has an especially bad problem.

There is definitely potential for this pest, because it can feed on many host plants in agricultural and urban settings.

Jhalendra Rijal, entomologist

The “marmorated” in the name refers to the bugs’ marbled coloring. “Stink” is what they do when crushed by a farmer’s or gardener’s boot. They can latch onto people’s clothes and travel in their cars to new places where they might reproduce.

Rijal said growers in the East have increased pesticide spraying to deal with the threat. Researchers are looking into other methods, such as a wasp that acts as a parasite on the stink bug, and traps that use substances that disrupt the mating cycle.

The threat to almonds and walnuts still must be researched because neither are grown in the East, Rijal said. He plans to work on the stink bug in his new job as integrated pest management adviser for Stanislaus, Merced and San Joaquin counties.

The Stanislaus County Agricultural Commissioner’s Office has a network of traps for high-risk pests such as the Mediterranean fruit fly, glassy-winged sharpshooter and red imported fire ant. The stink bug is not enough of a threat so far to be part of it, Commissioner Milton O’Haire said.

Stink bugs also can damage ornamental plants, fruits and vegetables in home gardens, and make their way inside.

“An efficient way to collect stink bugs indoors is by sucking them up with a dry or wet vacuum,” a UC website advises. “The bugs will cause the collection canister or bag and other parts of the vacuum to give off an unpleasant stink bug odor, so some people dedicate a vacuum cleaner to stink bug capture only.”

John Holland: 209-578-2385

At a glance

What: Brown marmorated stink bug (Halyomorpha halys)

Origin: Eastern Asia, mainly China, Japan, Korea and Taiwan

U.S. presence: The bug was first detected in Allentown, Pa., in 1998. It has since done major damage to crops and gardens from Pennsylvania to North Carolina. It has been found in 43 states, with varying losses.

Valley’s high-risk crops: Grapes, nectarines, peaches, pears, apples, tomatoes, sweet corn, chard, green beans

Moderate risk: Apricots, asparagus, blueberries, brocoli, cauliflower, cherries, lima beans and a few others

Unknown: Almonds, walnuts, pistachios, citrus, kiwi, strawberries, olives, plums

Spotting

a stink bug

Description: The brown marmolated stink bug grows to five-eighths of an inch and has marbled coloring. It is commonly mistaken for other species of stink bug.

What to do: People who suspect they have spotted the bug should place it in a sealed container, note the date and location, and call 800-491-1899.

More information: www.stopbmsb.org

Sources: California Department of Food and Agriculture; University of California

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