Farmers Create Vacuum in a War Against Harmful Insects : Devices Lift Bugs Off Crops, Reduce Need for Chemicals

The idea of zapping bugs by sucking them off crops instead of spraying them with toxic pesticides is causing a proliferation of names playing on “vac,” as in vacuum.

It all started last year when Driscoll Strawberry Associates Inc. of Watsonville designed a machine called a BugVac that uses just enough suction to remove lygus bugs from the tops of berry plants while not disturbing beneficial bugs that congregate farther down the plant.

That idea helped spur Salinas-based Tanimura & Antle Inc., the nation’s second-largest lettuce grower, to develop a machine called Salad-Vac to vacuum bad bugs off lettuce.

Now comes VAC-US, designed by two Delano men for use on grapes and cotton.

The Delano device consists of a specially designed, five-horsepower hydraulic fan that collects bugs in wire mesh bags after sucking them off plants, said Harold Nelson, who designed VAC-US with Don Neumann, his partner in Daco Farm Supply.

The 50-pound vacuum units can be frame-mounted in several configurations to accommodate individual requirements of farmers, Nelson said.

He and Neumann have begun field tests of a six-unit, tractor-mounted implement with three units on each side hydraulically positioned around a row of grapevines. They think it could be profitable because the cost of about $20,000 for an eight-unit VAC-US is considerably less than other types developed so far.

A VAC-US unit on top of the vines and one on each side can remove up to half the flying insects on the plants as the tractor moves between rows, Nelson said.

Even though it doesn’t eradicate all flying pests in a single application, Nelson thinks VAC-US will be valuable as another tool to let growers rely less on pesticides.

“We’re not a replacement for chemicals,” he said. “We’re a tool to help reduce the amount of chemicals needed. People are looking at how to reduce pesticides, and this is another concept.”

However, Nelson thinks repeated vacuumings will remove most flying insects, and the number of times a grower would need to vacuum plants depends on a particular insect’s life cycle. He estimated that a single application of pesticides would cost about as much as three sweeps of a field with VAC-US.

It can be used to remove leaf hoppers, white flies, moths, weevils, thrips and lygus bugs from strawberries, grapes and cotton, he said.

After flying insects are sucked off the plants, beneficial predator insects can be introduced to eliminate mites and other bugs, Nelson said. The wire mesh bags are designed with openings large enough to allow some surviving predators to escape.