Controlling Western flower thrips in peppers and tomatoes increasingly relies on a many-pronged integrated pest management program with new, promising pieces.
Dubbed the "push-pull strategy," the approach focuses on pushing the pest, which vectors major diseases such as tomato spotted wilt virus, away from the target crop and pulling in additional predators such as minute pirate bug.
One already proven piece of that strategy is the use of ultraviolet-reflective mulch, says Joe Funderburk, professor of entomology at the University of Florida's North Florida research lab in Quincy.
"It works really well for a lot of day-flying insects," Funderburk says.
Many growers have adopted reflective mulches for their aid in pest management as well as their horticultural benefits. When temperatures climb, the light-bouncing fabric helps keep soil cool enough to show a yield bump, he says.
That aspect can be a mixed blessing, however. Winter use, for example, can turn soil too cool for pepper roots, he says.
Growers soon may be expanding their push-pull efforts with companion plantings and sprays of a kaolin clay-based material, based on two years of small-scale research.
"I'm convinced they'll play a big role in the IPM system in the future," he says.
This year Funderburk and his team plan to step up their study to field trials in 5- to 10-acre commercial plots.
Clay spray helps repel thrips
Spraying Surround—a crop protectant that incorporates kaolin clay—appears to have the strongest deterrent effect on Western flower thrips, says Kara Tyler-Julian, a master's student working with Funderburk at the Quincy lab.
But because it also repels minute pirate bugs, growers may need to use it only early in the season until scouting turns up predators in the fields, Tyler-Julian says.
Galen Frantz, senior crop management specialist at Glades Crop Care Inc. in Jupiter, says the use of Surround and reflective mulch during the pepper trials yielded no discernible thrips damage and "very little" overall insect damage—without insecticide sprays.
Yields showed no differences between the test and control plots, he says.
Not all thrips are created equal
Florida flower thrips populations jumped when peppers began to bloom, but so did the numbers of predatory minute pirate bugs, Frantz says.
Eastern flower thrips and Florida flower thrips are native species that pose a far smaller threat than Western flower thrips, he says. They do less damage, are poor disease vectors and are less likely to develop pesticide resistance, making them easier to kill.