As another winter turns to spring, bears aren't the only things coming out of hibernation. Azalea lace bugs are waking up, too, and will soon damage prized azaleas if homeowners don't take action.
Azalea lace bugs are the main pests of landscape azaleas, say University of Georgia entomologists. The insect with the beautiful, lacy wings can cause ugly damage to azalea foliage.
Lace bugs feed on the underside of leaves and extract the contents of the upper layer of cells. This causes the azalea leaves to appear bleached or mottled.
Kris Braman, an entomologist with the UGA College of Agricultural and Environmental Sciences, said early spring is the perfect time to check plants for azalea lace bugs. Controlling them now, while they're young, is the key, she said.
"The azalea lace bug spends the winter as an egg inside your azaleas' leaves," Braman said. "Now that the temperatures are warming, the eggs are beginning to hatch. And newly emerged nymphs are beginning to feed."
Braman said a properly scheduled insecticide application will get rid of these nymphs before they mature and have time to lay eggs.
"If you don't kill them before May, they will have laid eggs, and you'll have to spray several times," she said.
If not controlled, azalea lace bugs can produce four generations from spring to fall. "If you kill this first generation," she said, "you may not have to spray again."
UGA entomologists urge homeowners to use less toxic insecticides to save the good bugs in the landscape.
"Using less toxic insecticides allows you to conserve beneficial insects like the parasitic wasps and spiders that feed on lace bugs," Braman said.
"Horticultural oils and insecticidal soaps have been around a long time," she said. "People are using them more now. But you need to remember that these are strictly contact insecticides."
Contact insecticides must be sprayed on the insects. They work best on soft-bodied bugs like aphids and lace bugs.
"They have no residual activity on the leaves," Braman
beneficial insects can walk on that leaf surface, after
the fact, and not be killed. Good
contact with lace bugs on the underside of the leaves is
important for good control."
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|If homeowners don't spray for azalea lace bugs,
Braman said, young plants will suffer
the most damage.
"In our research," she said, "we have observed that older plants, those that have been in the landscape for several years, can withstand more lace bug damage. They can tolerate some damage because they have well-established root systems and are not already under stress like a newly transplanted azalea."
Braman said this is one reason homeowners keep
replacing young plants year after year.
(Sharon Omahen is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)