Mating Game Is Fixed for Sterile Medflies

It was what thousands of malathion-weary residents have been awaiting for months: the arrival of millions of sterile Medflies as a welcome substitute for aerial pesticide spraying. But as Lourdes Sanchez found out Wednesday, somebody apparently forgot to tell a couple of overly eager insects about the plan.

As the gloved Sanchez tapped at the bottom of a fly-filled bucket, most of the 4,500 pink-dyed pests inside flew furiously down Whittier Boulevard in the quest for fertile Medflies to breed into oblivion.

But there on the side of the pickup truck sat a couple of troublesome and entangled flies that had begun the mating game a bit early.

“They’ve jumped the gun,” said the 27-year-old Sanchez--”Mama Medfly” to her 3-year-old son--as she tried to flick the pair away. “I guess that’s what happens when you’ve been in captivity.”

Such are the pitfalls for the several dozen work crews who began spreading the sterile Medflies around the northern tip of Orange County late last week and will continue to do so through summer there and in about 234 square miles of Southern California.

The releases mark the state’s latest attack on the Mediterranean fruit fly, a strategic shift that is, by most accounts, a welcome reprieve from months of unpopular malathion sprayings.

About half of the more than 400 square miles of Southern California’s spray areas are now being switched from spraying to the release of steriles, and state officials--while overly confident in past projections--predict that virtually all areas will be switched by next month.

No sterile flies will be released in Orange County’s largest spray zone, a 36-square-mile area centered in Garden Grove. Instead, it is scheduled to get two more aerial malathion applications after Wednesday’s application. Agriculture officials hope they can finish the Garden Grove area’s treatment by May 30 and thus avoid using the hard-to-come-by sterile flies, which are bred in Hawaii and dyed pink to avoid confusion with wild, fertile flies.

For most residents in the eight-square-mile spray zone around Brea, La Habra and Fullerton, however, the arrival of the steriles is good news.

As some residents stared curiously at the odd sight Wednesday afternoon, a crew of four state workers cruised the streets of Brea for two hours, leaving a path of a half-million sterile Medflies in their wake. The process is aimed at distributing the specimens evenly throughout infested areas to try to breed the fertile flies out of existence.

“I’m delighted by this because it means they won’t be spraying here any more,” said La Habra Mayor Beth Graham, who has heard increasing complaints about the aerial malathion applications since they began there in late November.

“We’ve had a lot of people upset by the sprayings. There are always going to be some people who will protest anything, but this (sterile release program) is much preferable.” Graham said. “Certainly, there’s no reason to fear these sterile Medflies, and if they accomplish the same thing, great.”

But there is some debate over the efficiency of the sterile releases.

Scientists concede that they are still puzzled by how the process works--for example, whether it is the sterile males, or females, or both, that break the reproductive cycle. (The state is releasing both sexes.) They acknowledge that the success of the technique--rarely tried on a scale as large as Southern California--is far from guaranteed.

Although many residents seem to favor sterile flies over spraying, there has still been some grumbling.

“The public in general has been just really misinformed about what this is all about,” said Greg Guntle, a sterile release supervisor who oversaw Wednesday afternoon’s distribution in the Brea area--the fourth there since last week. “The biggest misconception is that we’re actually spraying (malathion).”

Some residents have angrily stopped the trucks to find out just what was going on, Guntle said; a few people have even thrown rocks and other objects at the trucks.

And several residents in Whittier--where the state has been releasing the sterile flies for months--complain that the insects seem attracted to fresh paint and have stuck themselves to newly painted walls.

For Sanchez, who worked from the back of the truck Wednesday in Brea to release the flies, it is this occasionally negative reaction from the public that she says makes her job the toughest. “Some people just don’t understand,” she said.

Sanchez, unemployed until she saw an advertisement for an agriculture aide in February, says she really enjoys the work.

The flies come out readily and need only a bit of coaxing in cold weather. And flies that constantly surround her, occasionally nesting in her hair, aren’t much of a problem, she insists.

“The flies really don’t bother me,” she said as she sent another batch skyward. “If they were killer bees or something, I’d have problems. But these guys are harmless.”