Spring Pests Arrive Early; LSU AgCenter Entomologist Says Warmer Weather To Blame

Dale K. Pollet, Blanchard, Tobie M.  |  3/9/2006 2:39:47 AM

News Release Distributed 03/08/06

Insects don’t watch the calendar. Instead, weather is a big factor in their life cycles. So this year’s mild winter and the rising temperatures we’ve seen lately have set up a perfect scenario for early emergence of spring pests, according to an LSU AgCenter expert.

"It seems we are seeing some insects a little early because of the warm weather," said LSU AgCenter entomologist Dr. Dale Pollet.

One early-appearing insect is the larval stage of the June bug or white grub. In Louisiana, the white grub usually doesn’t appear until late April.

"These pests are already creating some concern for homeowners in the lower part of the state," Pollet said, explaining white grubs damage turf grass and could attract larger pests to your yards.

"If you have a bad problem with white grubs in your yard, you can get things like raccoons, possums, skunks and coyotes digging up holes in your yard – trying to get them as a food source," Pollet said.

The best treatments for the grubs are Mach 2, Sevin or Merit, according to Pollet, who explains Mach 2 is a growth regulator and environmentally safe. The others are insecticides.

Early warm spells also have caused trees to bud early, but subsequent freezes then damaged many of these buds. That problem and the number of trees damaged by storms last year have created an ideal environment for bark beetles and shot hole borers, Pollet said.

The borers and beetles drill into trees, but it is not the holes that do the most damage, according to the LSU AgCenter entomologist, who explained these insects carry fungus that they inject into the damaged tree tissue.

"The fungus kills the branch," Pollet explained. "The beetle and the beetle larvae feed on the fungus."

Pollet recommends pruning trees that are injured or stressed to avoid further damage from infestations.

Large populations of the crane fly also are out this year. Pollet said these long-legged flies scare people each year when they first appear.

"Many think of them as giant mosquitoes and panic," he said.

Crane flies do not bite, but they can be a nuisance. They are attracted to lights and often enter homes through doors and windows.

Spraying a pyrethroid around doorways can help keep the adults from entering the home, Pollet said, adding that changing a light bulb also can help.

"If you put amber light outside, it will reduce the numbers of crane flies," Pollet said.

Another of the pests that are out early this year are lace bugs – the primary pest of azaleas. Pollet said these pests are particularly emerging as problems in azaleas planted next to buildings, since those plants receive more warmth because of heat radiated from the building walls.

"This extra warmth has caused a portion of the populations to hatch out early and begin feeding on the foliage," Pollet explained.

Lace bugs can be treated with Orthene or Merit, but Pollet said not to treat unless you find nymphs on the plants. You can check for nymphs by knocking the foliage against a sheet of white paper.

"It’s always better to monitor and observe your pests before you spray," he said.

Other pests out early this year include spider mites and the Florida wax scale, according to Pollet, who said ultra fine oils can help manage these insects that feed on the foliage of plants.

Unfortunately, just because these insects are appearing early, that doesn’t mean they will disappear early, the LSU AgCenter entomologist said, adding that he believes we will likely see more generations of the early-appearing insects.

For more information related to home lawn and garden care, as well as a variety of other topics, visit www.lsuagcenter.com or your parish LSU AgCenter Extension Service office.


Contact: Dale Pollet at (225) 578-2370 or dpollet@agcenter.lsu.edu
Writer: Tobie Blanchard at (225) 578-5649 or tblanchard@agcenter.lsu.edu

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