Area White Fly Infestation Has Strawberry Growers Concerned

An unprecedented white fly infestation that can ruin strawberries has officials and growers concerned about a new threat to Ventura County’s second-most-important cash crop.

The greenhouse white fly, which causes a black sooty mold that makes strawberries unmarketable, has been found on about 150 acres of summer strawberries on two Hueneme Road fields half a mile apart east of Oxnard.

It is one of the heaviest concentrations of the pest on strawberries ever seen in California, said David Riggs, president of the California Strawberry Commission.

“Historically, white fly has kind of been considered a nuisance pest rather than an economic pest,” he said. “But at the levels we’re seeing it’s clearly retarding the plants and has a clear impact on the crop. And white fly in general is important to control not just for strawberries, but other crops.”

Heavy populations of the fly can infest such crops as squash, cucumbers, peppers, tomatoes and several varieties of beans, officials said.

The unusually humid summer is being blamed for providing conditions conducive to a population explosion of this particular white fly species, which is more commonly found in the warm environment of greenhouses.

The bugs, little more than large white dots, can be seen flitting along the rows of maturing berries. More visible are their moldy by-product that leaves ugly black blotches on the plants and fruit.

Alarmed officials with Reiter Brothers Inc., one of the largest strawberry growers on the Oxnard Plain, have been battling the unexpected menace for the past month.

“Anybody we’ve brought out here--from entomologists to the local agriculture commissioner--haven’t believed it until they’ve come out here to see it,” Gerry Robertson, the company’s operations manager, said. “We’re looking at a potential crop loss here of 25% to possibly 100% if we can’t find a control for this.

“If conditions continue to be favorable for the white fly, new plantings of strawberries coming up in the next 1 1/2 months could be affected.”

Company officials have even contemplated digging up the entire crop.

With the county’s peak planting season for most varieties of strawberries coming up in the next several weeks, traditionally jittery farmers have made the infestation the talk of the close-knit industry.

“We don’t have anything else to talk about at this time of year,” said Mike Conroy, who farms about 150 acres of strawberries on the Oxnard Plain. “All of us are quite susceptible to it.”

Last year 5,218 acres of strawberries were planted in Ventura County with a cash value of $143.5 million, said David Buettner, the county’s chief deputy agricultural commissioner.

Still, he believes the infestation will not rage throughout much of the local strawberry crop.

“With this pest there’s no real indication it would spread rapidly outside of the Hueneme Road environment because it’s been building up there for a while,” he said. “It’s not the type of pest that would spread and wreak havoc over the entire county.”

That is no comfort to Reiter Brothers, which has so far invested about $7,500 to $8,000 an acre in its summer strawberry crop.

The figure does not include the labor-intensive cost of trying to rid the fields of the pests or the potential loss from fruit that cannot be sold.

Robertson is using two techniques to combat the problem because there are no effective pesticides to use on the fly.

The best method discovered so far is to spray the plants with water and detergent, using a high-pressure hose system mounted on a tractor to remove the mold from leaves and fruit.

Crews working 20 hours a day began rinsing the plants about three days ago and completed the first 75-acre field Thursday, Robertson said. Now they will start over again.

The second tactic involves the use of a tractor-mounted “bug vac”--three 24-inch diameter vacuums that suck up flies and uses rapidly rotating blades to chop them into pieces as the vehicle moves down the plant rows.

“It’s hard to evaluate how well that’s working because you can’t find these things chopped up dead on the ground,” Robertson concedes.

An entomologist from UC Riverside is also helping tackle the problem.

The hope is the infestation will diminish as the days grow cooler, though no one knows for sure whether warm weather is responsible for the fly increase.

But company officials believe they’re making progress and fears that the entire crop could be lost have diminished somewhat as the battle against the bugs has intensified.

“We’re making all this up as we go along,” Robertson said.