A single application of that product provides season-long systemic, 12 months of residual control of insect pests on trees and shrubs. Do not use when the ground is waterlogged. Otherwise, you can use it whenever things get out of control. Leaf damage from lacebugs looks bad but the plant(s) itself should recover. New spring growth will help hide the old damaged leaves. I got the following information from the Azalea Society's Website:

"Azalea lacebug: Upper surface of leaves has a gray, blanched, or coarse-stippled appearance. The undersides of the leaves become discolored by excrement and cast skins.

Spray undersides of the leaves with Malathion, dimethoate (Cygon), or acephate (Orthene). Repeat application every 10 days until control is obtained."

Luis

This is not the best time to use a systemic. Your efforts might best be used to apply horticultural oil a few times during the fall and winter season, making sure that you get the spray on the underside of the leaves, and down the stem.

Get rid of the fallen leaf debris over the winter, as eggs may be embedded in those, as well as the leaves still on the plant. That's why a systemic is not effective at this time of year...you need to concentrate on the eggs!

Early next spring, begin treatment of ALL of your azaleas. You could continue with the oil sprays and you could use insecticidal soap, or you could go ahead with your systemic application if you feel that you must. The secret to lacebug control is catching an outbreak before it gets to the point where the leaves are turning yellow and falling off. Lacebugs are easy to spot, and can be located even on seemingly healthy plant if you keep your eyes open.

Imidacloprid, the active ingredient in the Bayer systemics, is under very severe scrutiny all over the world, and some countries will probably ban it before too long. It is believed to be causing severe problems with honey bees and other pollinating insects. Just a thought.

I was able to get rid of a very heavy infestation of lace bugs with insecticidal soap, applied 3 times, a week apart. I made sure I covered the underside of the foliage as well. This was two years ago. The plant was not growing too well, so I thought I would cut it back to about 12" from the ground, which I did. This year, it is about 5' tall; rebounded wonderfully. It is an evergreen azalea, I do not know the name because it was here when I bought my house. Lace bugs are a big problem in Oklahoma, though, and insecticidal soap is the least toxic of all ways to treat this problem. Since it worked, I didn't need to resort to more drastic measures.

At first, I thought the plant had red spider, the way the leaves looked bleached out. Then, I thought it was sun burn. Finally, I figured out the problem was lace bugs.

I did pull out the debris, and put fresh pine needles down for mulch. THe following spring, I fertlized with liquid acid fertilizer. I don't fertilize it very much, and so far I haven't had any problems with iron chlorosis. Maybe because I mulch it each year with fresh pine needles?

Susan

Hi casanova,
How are your Azaleas doing now? Hopefully fully recovered.

What did you do?
I discovered a have a problem with lacebugs on my azaleas and posted another thread on the Azaleas and Rhododendron Forum, "Azaleas getting sick, please help!!!".

I will appreciate your help.
Thanks