Trees in 16 Florida counties under attack by southern pine beetles

May 18, 2001

GAINESVILLE, Fla. — A record attack of Southern pine beetles in Florida may become worse still if ongoing dry conditions continue, University of Florida researchers say.

“This is the worst outbreak in documented Florida history, and if drought conditions continue it could become a very expensive situation,” said John Foltz, associate professor of entomology with UF’s Institute of Food and Agricultural Sciences.

Officials at the Department of Forestry said 16 counties currently have pine beetle infestations: Alachua, Baker, Gilchrist, Hernando, Marion, Duval, Jefferson, Putnam, Lake, Walton, Orange, Columbia, Hamilton, Lafayette, Volusia and Suwannee. Alachua is in outbreak conditions, they said, and Marion is on the verge of an outbreak. Those counties that reach outbreak condition are eligible for federal grant money to help with suppression efforts.

The biggest obstacle to containing pine beetle infestations is the lack of awareness on the part of the private property owner, Foltz said.

“Part of the problem with reluctant homeowners is that trees can continue to look healthy for a short period of time after infestation,” Foltz said. “Many homeowners don’t realize they could have a healthy pine tree one day, and by the following evening 5,000 beetles have destroyed the tree.”

Experts advise taking quick action against outbreaks. But determining if pine trees are infested can sometimes prove difficult, especially during drought conditions when trees contain less sap. Foltz said trees with low sap content will not have the traditional light-yellow pitch tubes protruding from the bark, which is a primary clue that beetles are colonizing a tree.

Other signs to look for are dust around the base of the tree — a byproduct of bore holes — and needles turning a greenish-yellow, which means beetles are still in the tree. If the needles turn orange or red, the brood has emerged and the tree is lost.

“We like to find the infected trees within the first 30 days, so we can remove the tree and spray it before the brood has emerged to destroy other trees,” Foltz said. “The usual method of control is to cut down the trees and then spray and remove the remains.”

Experts do not recommend that property owners spray insecticide on standing pine trees because the beetles live as high as 50 feet up the tree. Some tree-removal companies spray only as high as 20 feet up, which Foltz said kills maybe 10 percent of the beetles.

The cost for spraying a tree runs around $40, while cutting and removing a tree costs from about $200 up to $1,200.

Residents who want more information may call the Florida Department of Forestry at (850) 488-4274, or visit the state Web site: www.doacs.state.fl.us.