University of Florida researchers want to play an optical trick on the insect that spreads a deadly tomato disease by camouflaging plants.


In tests conducted with kaolin clay mixed with plant essential oils, the researchers and their Agricultural Research Service counterparts found tomato plants had about half as much tomato spotted wilt virus, according to a news release.


The kaolin clay forms a white coating on the plant that may interfere with the thrips' ability to locate tomato plants. says Stuart Reitz, an entomologist with the ARS Insect Behavior and Biocontrol Research Unit’s Tallahassee, Fla.


Those that do land may find the clay layer difficult to penetrate with their juice-sucking stylette.


If the thrips can't feed, they can't infect the plant with the tomato spotted wilt virus.


If tomato plants are infected when they're young, they may die or yield little, if any, fruit.


Plant pathologists Timur Momol and Steve Olson at the university’s North Florida Research and Education Center at Quincy collaborated with Reitz.


In the trials, kaolin clay alone reduced disease incidence by 33 percent.


The plant essential oils—tea-tree oil, lemongrass oil or geranoil—further reduced disease incidence by 17 percent.


Northern Florida tomato growers have successfully used reflective mulches to repel the thrips. But smaller growers may find the ground cover too expensive, Reitz says.


The kaolin and plant essential oils are less expensive and may be a viable option, he says.