Southeast Production: Rindworm Management in Watermelons

Web AdminWatermelon

By Clint Thompson

Watermelon producers in the Southeast should be wary of the presence of rindworms in this year’s crop. Insecticide sprays are available for growers who need to control populations of the various worm species like corn earworm, fall armyworm and beet armyworm.

Rindworm management
Rindworm damage on watermelon. Credit: K. Rochacewich, Cargill.

Intrepid and Coragen insecticides are ideal choices for farmers to utilize, according to Bob Hochmuth, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Regional Specialized Extension agent in Live Oak, Florida.

“About a week ago, we started seeing a fresh hatch. It’s the first of a significant hatch. We’ve been pretty lucky most of the season until (two weeks ago),” Hochmuth said. “It’s not unexpected. It’s probably just a little later appearing than expected given the crop advancement. We do have a higher population of hatching of the various species that make up the rindworm complex.”

The rindworms can be devastating because they will feed on the rind. Their feeding causes light-colored blotches on the rind, which makes the fruit less marketable, according to UF/IFAS.

Hochmuth said damage had been very light up until this point in the season, though a large hatch of eggs and small worms were discovered. Growers need to continue to scout for any damage and spray every week.

Early planted fields that have been harvested three or more times may not need continued
rindworm sprays if the fruit is not being fed on and if only a week or so is left in the harvest
period.