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Japanese beetles found in Merced

The Japanese beetle, a major pest on the East Coast, has been found in the City of Merced.

David Robinson, the agriculture commissioner for Merced County, said that one of the beetles was found in a trap in southwest Merced.

"This is a major pest that is extremely destructive," Robinson said. The beetles can attack both ornamental landscape plants and ag crops, including corn, grapes, alfalfa, strawberries and peaches. The larvae feed on roots, while the adults munch on the leaves and fruit of more than 300 crops. About $460 million is spent in the United States to control the beetle.

Robinson said that his office staff is putting out about 490 beetle traps in and around the area where the pest was found, a total of about 59 square miles. This is the first time the beetle has been found in Merced County, Robinson said. The traps will be put out for the next three days, and the traps will be monitored for at least three years.

"We have 25 vehicles out putting these traps up right now," Robinson said. "The traps are going to be in yards and other public places, and we are asking that the public leave the traps alone."

Scents, food and color are used to lure the beetles into the traps. The traps are not toxic to humans, Robinson said.

An adult Japanese beetle is about 1/2 inch long and has a shiny, metallic-green body and bronze-colored out wings, with small tufts of white hair along the sides of the body.

The Japanese beetle should not be confused with the more common hoplia beetle. This beetle, smaller and not as shiny as the Japanese beetle, is a common rosebush pest. It only affects roses, and is found throughout California.

The first Japanese beetle was found in the United States in 1917, and came from Japan. There have been three infestations of the pest in California, but all have been eradicated.

"This is the first time in my 20 years in agriculture that I have seen this beetle," Robinson said. If more of the pests are found, Robinson said that the county will have to find treatment for the areas where the beetles have been found.

The beetle has been found at airports in California, where it probably ended up after hitching a ride on airplanes. California is perfect for the pest, because there are extensive plantings of irrigated grass in yards and parks for the larvae to feed on. There are no natural enemies of the beetle in California.

Robinson said that the Japanese beetle was found during a normal insect detection program.

"I hope that this is the only one we find, but if we find more, we will start a program to get rid of it," he said.

Reporter Carol Reiter can be reached at (209) 385-2486 or