Dear Monique,

Dr. Pscheidt passed your query on to me. 

Keep in mind that right now, azalea lace bugs are present in the egg stage. Azalea lace bug eggs are inserted INTO the plant, along leaves and branches. Thus, many insecticide treatments, applied right now, will have little to no effect on the eggs, since they are physically protected within the plant.

It's also important to keep in mind that the damage you see is last year's damage. The plant will 'wear' that damage, long term. You just have to wait for the plant to 'grow out' of the older damage, when it grows new leaves in the spring.

The key to controlling azalea lace bug on  your plants, when you know that you had an infestation in the past, is to carefully monitor your plants in the spring. You want to catch the newly emerging nymphs, when they are freshly hatched out of their eggs. This is when they are most vulnerable. And, this is when you can have the biggest positive impact on control. In fact, studies at OSU have found that using strong water sprays, to physically wash the nymphs off of your plants, is an effective form of management . . . IF you catch the nymphs when they hatch, early in the spring. If you don't catch them early in the spring, they will move onto the fresh, tender leaves of your plants, and the damage cycle will start anew.

I've listed the chemical control options in the Pacific Northwest Management handbook, for azalea lace bug, and added notes for your to consider. If you are looking for the least toxic option, I would recommend carefully monitoring your plants in the spring, and using the water spray option. If chemical controls are necessary, I would choose an organic pyrethroid.

• azadirachtin: there is some evidence that applying azadirachtin to azalea leaves and branches can kill overwintering eggs. But, the effect sizes are fairly small and weak, often not statistically different than control treatments.
• carbaryl: a broad spectrum insecticide, that will harm beneficial insects. 
• clothianidin: a systemic and broad spectrum insecticide, that will persist within your plants for a long period of time. Can take 14 days before control is seen, after application.
• dinotefuran: a systemic and broad spectrum insecticide, that will persist within your plants for a long period of time. Once applied, control can be seen in as little as three days after application.
• esfenvalerate: a type of synthetic pyrethroid (see below).
• fluvalinate: a type of synthetic pyrethroid (see below).
• horticultural oils: like water sprays, can be effective if applied early in the spring, during first hatch. Must make sure to get good coverage of plant, particularly the undersides. You may want to test out the oils on a small section of your plants, before coating entire shrubs, to make sure that you don't get leaf burn.
• imidacloprid: a systemic insecticide, that will persist within your plants for a long period of time. Can take several weeks before control is seen, after application.
• organic insecticidal soap: like water sprays, can be effective if applied early in the spring, during first hatch. Must make sure to get good coverage of plant, particularly the undersides. You may want to test out the oils on a small section of your plants, before coating entire shrubs, to make sure that you don't get leaf burn.
• malathion: a broad spectrum insecticide, that will harm beneficial insects. 
• organic pyrethrins: effective at managing azalea lace bug. These are broad spectrum insecticides, that may also harm beneficial insects. Since pyrethrins are organic, they degrade quicker in the environment, which may help limit negative effects on beneficial insects.
• synthetic pyrethroids: effective at managing azalea lace bug. These are broad spectrum insecticides, that may also harm beneficial insects.
• organic spinosad: research trials show that this pesticide is relatively ineffective at controlling azalea lace bug.

Dinotefuran is known as a 'quick in, quick out' systemic. You want to time the application so that you are just ahead of the egg hatch, in the spring. In Western Oregon, egg hatch has been occurring in early May. I would apply the product in late April, early May, according to label directions. You can also reach out to us, again, to see how winter/spring degree days are accumulating, and what OSU is predicting for Azalea Lace Bug emergence, in 2022.

There may be label restrictions, that prevent the use of this product just prior to or when the azaleas are blooming, in order to protect bees.