Malathion Spraying Will Be Expanded in L.A. County : Agriculture: Parts of Rowland Heights, Diamond Bar and Industry will get aerial applications of pesticide. Two Medflies were been found in the area recently.

The state’s aerial spraying campaign against the Mediterranean fruit fly spread Thursday to previously untouched portions of northeast Los Angeles County after the discovery of a Medfly in a loquat tree.

The immature female fly was trapped Tuesday in residential Rowland Heights, slightly more than a mile away from where another fly was found 2 1/2 weeks ago in neighboring Diamond Bar.

Agriculture officials announced Thursday that a 16-square-mile sector encompassing parts of Rowland Heights, Diamond Bar and Industry will be sprayed twice with the pesticide malathion beginning at 10 p.m. next Wednesday. The sprayings will be followed in early May with the release of millions of sterile Medflies, used to breed the pest out of existence.

The new aerial campaign marks the first expansion of the spray zone since February and comes just as state agriculture officials are preparing to phase out aerial spraying in 366 square miles of Los Angeles and Orange counties by May 9.

Malathion spraying in Orange County encompasses an eight-square-mile area that includes parts of Brea, La Habra and Fullerton, as well as a 36-square-mile area that includes nearly all of Garden Grove, about half of Westminster and parts of Anaheim, Orange, Santa Ana, Huntington Beach, Cypress, Los Alamitos and Stanton.

Rex Magee, associate director of the state Department of Food and Agriculture, said the new spray zone will not affect the May 9 deadline.

“This won’t change the deadline or anything else,” he said.

Four rounds of malathion spraying remain for Orange County areas. Spraying is scheduled for April 16 and April 30 in Brea, La Habra and the Fullerton region, and April 19 and May 3 in Garden Grove and nearby cities.

But some of the state’s own scientific advisers are skeptical that the deadline can be met. “I’ve always felt May 9 was extremely, absolutely premature,” said Richard Rice, a UC Davis entomologist and one of five scientists on the state’s Medfly Science Advisory Panel. “This is the first of probably many finds. I hope that date isn’t locked in concrete.”

UC Davis entomologist James R. Carey, another member of the panel, said he believes that the two Medflies found in Rowland Heights and Diamond Bar are only the beginning of a spring resurgence of the pest.

Carey said the vast majority of Medflies detected over the last 15 years have been found in late summer and early autumn, when the temperature and the availability of fruit both peak.

He said the discovery of a Medfly in Rowland Heights confirms his fear that the war against the Medfly, which began last July with the discovery of a single fly near Dodger Stadium, has only started.

“They’re in deep trouble,” Carey said. “This is just the beginning.”

Word that aerial spraying will soon start in the three communities, located about 20 miles east of Los Angeles in the San Gabriel Valley, sparked a strong reaction from local officials, who have watched with increasing anxiety as the state’s spraying campaign worked its way around their borders.

Diamond Bar Councilman Paul Horcher said he was prepared for the announcement about the start of aerial spraying but still found it upsetting.

“I’m getting sick of it all. I think the whole valley is,” Horcher said. “It’s clear the citizens here are being used as backstops for mistakes the agriculture people have been making. We thought this was wrapping up. I guess not.”

Councilman Gary Werner said the announcement of spraying was a frustrating development because of the state’s apparent inability to control the spread of the pest.

Werner was the sponsor of a Diamond Bar City Council resolution last month opposing aerial spraying over its territory.