Fruit flies found in East Contra Costa County

EAST COUNTY — Crews began treating areas of Oakley, Brentwood and Antioch to eradicate invasive peach fruit flies after four were recently discovered, posing what officials call “a statewide imminent danger to the environment and the economy.” Karen Ross, secretary of California’s Department of Food and Agriculture, said in a website notice Thursday that authorities have determined following weeks of trapping and surveys that a breeding population and infestation exists in parts of East Contra Costa County. The peach fruit flies were trapped between July 31 and Aug. 14 in residential neighborhoods in Oakley and Brentwood, according to a notice posted on the Department Food and Agriculture website and emailed to government officials Thursday night. The peach fruit fly is considered “a devastating pest of a wide variety of important fruit and vegetables,” including peaches, pears, apples, apricots, citrus, tomatoes, cucumbers, watermelons, figs, dates and avocados, according to the department. State officials said that after original trappings detected fruit flies in peach, apple and fig trees, additional surveys were done to determine the extent of the infestation and the area that needs treatment. Based on those results and recommendations from Contra Costa County agricultural commissioner representatives, it was decided that chemical treatment, and possibly host fruit removal, would be the best ways to eradicate the peach fruit fly, the notice said. Treatment will begin Saturday, according to Jennifer Gordon of the California Department of Food and Agriculture’s Pest Detection/ Emergency Projects. “It (East Contra Costa County) is not a normal spot for us to get them — that’s why we wanted to jump on it right away,” she said. “If we get it early enough, we don’t normally find any more.” JJ Sohal, the department’s senior environmental scientist, said field specialists will place up to 400 bait stations over the next three days in the approximately 19-square-mile affected area. The baits, which contain the organic pesticide Spinosad, are meant to attract male peach fruit flies by mimicking the females. The flies are killed when they ingest the insecticides, she said. Applications will be repeated every two weeks throughout the flies’ life cycles, which depend on temperatures, with warmer weather hastening the cycles, Sohal said. If East County’s temperatures remain high, the flies’ life cycles and treatment program will likely last about two months, she added. “We’re trying to get all the males,” Sohal said. “We have traps for the females too, but they are different.” The male attractant approach has successfully eliminated dozens of fruit fly infestations in California, according to Contra Costa County Agricultural Commissioner Matt Slattengren. Though fruit flies have been found in past years in other parts of the county, the commissioner said this is the first time in 20 years they have been discovered in East Contra Costa — only a mile from prime agricultural land. County officials plan to place dozens of additional traps in the four locations — three in Brentwood and one in Oakley — where the fruit flies were found and check them frequently. “It looks like we caught it early, but being that it is close to ag areas, that’s why we are so concerned,” Slattengren said.