UF/IFAS Wimauma facility finds "game changer" for state's strawberry crop

Chilli thrips, as the pests are called, feed on some 200 different species of plants, including tea, mangoes, roses, hydrangeas, cotton, and strawberries, a $500 million dollar-per-year crop in Florida.

But researchers at the University of Florida’s Gulf Coast Research and Education Center in Wimauma have found that two particular strawberry varieties, or cultivars, called Florida Brilliance and Sweet Sensation show a greater resistance to the pest than other cultivars that they tested.

“We found out that these two cultivars had low damage and high fruit production compared to others,’’ says Lovely Adhikary, the entomology doctoral student who led the research under the supervision of University of Florida Institute of Food and Agricultural Sciences assistant professor of entomology Sriyanka Lahiri.

Florida Strawberry Growers Association Executive Director Kenneth Parker calls the discovery “critically important" in a UF/IFAS press release.

“Selecting cultivars that have some level of defense against chilli thrips is a game-changer,’’ Parker says.

Adhikary says the research was conducted over three years in Lahiri’s lab. Florida Brilliance and Sweet Sensation, both bred for taste and fruit yield by UF strawberry breeder Vance Whitaker, showed a resistance that the others didn’t.

Chilli thrips eat both leaves and fruit. Though the damage does not seem to affect the taste of the berries, the visible damage to the leaves and fruit makes them look unappealing and therefore unmarketable, Lahiri says.

Chilli thrips, so named because they were discovered in chilli pepper crops in India, lay their eggs in the foliage of young plants.

“The female has a blade-like egg-laying apparatus, so it literally draws a slit in the leaf tissue and puts eggs inside the leaf,’’ Lahiri says.

Adhikary notes that the pests have “interesting mouth parts.’’

“They can dig into the cell and suck the cell content,’’ she says.

That causes the tissue to die. The pests also distort the leaves, creating brown spots on them, and discolor the fruit, causing fissures in it. The scientists do not yet know why Florida Brilliance and Sweet Sensation show better resistance to the pest. Lahiri says Adhikary is conducting a series of greenhouse studies to answer that question.

“We think there are a number of factors at play here,’’ Lahiri says. “The thickness of the leaves, the number of hairs on the leaves, the canopy size, the chemicals inside the plant, there are so many variables that it’s basically a combination of reasons why these two are particularly resistant to or tolerant of chilli thrips compared to the other ones.’’

Scientists believe the pest started in Southeast Asia. Chilli thrips were first discovered in Florida in 1991 in a port of entry on rose cuttings and moved to pepper plants in South Florida. Since then, the pest has spread across the Southeast and is showing up in Northeastern states, Lahiri says.

“We are unique in that strawberries as a host to chilli thrips is something new,’’ Lahiri says. “No one in the world has experienced this, what we’re experiencing in Florida.’’

For more information, go to UF/IFAS Gulf Coast Research and Education Center