I know I’ve been talking about lace bugs and how they’re decimating azaleas and rhodies in our area of the Pacific Northwest. Maybe I’m talking too much about it. But this is a new problem for us, and it seems that so many people around here adore their azaleas and rhodies. I’m merely trying to provide information on what we can do to have beautiful gardens in spite of this new pest. And without using environment-damaging, broad-spectrum insecticides.
I had a recent coaching visit, and that client told me a friend of hers had ordered lacewing bugs (I’m assuming larvae) in attempt to combat her lace bug infestation. Both of these bugs have the word ‘lace’ in their names, but see the photos at right that they are not the same. Lacewings are the good guys!
As of last year, I’d not heard of any organic methods of lace bug control other than horticultural oil or insecticidal soap, and hard sprays of water — and of course siting plants susceptible to lace bug attack in the best possible positions and giving them absolutely perfect culture according to their needs.
This lacewing thing was new info for me. And of course, I had to do some research. And UC Davis IPM Online did not let me down. Their IPM resource is one of the best around, and I use it routinely to find answers to my own questions. I found an article about lace bugs with info about beneficial insects that love to eat. YES!
Scroll down to the section on Biological Controls and you will read:
Natural enemies of lace bugs include assassin bugs, lacewing larvae, lady beetles, jumping spiders, pirate bugs, and predaceous mites. These predators may not appear in sufficient numbers until after lace bugs become abundant; their preservation, however, is an essential part of a long-term integrated pest management program. Growing a variety of species, mulching soil with organic material, and shading plants from afternoon sun can reduce lace bug damage to shrubs and increase natural enemy abundance. If applying pesticides, using only short-persistence materials such as oils and insecticidal soaps will minimize the number of beneficial predators and parasites that are killed.
Just look at all the beneficial insects that will help you control lace bugs! And lacewing is among them. And note the author mentions paying close attention to azalea culture needs, just as I’ve yammered on and on about. And finally, using the oils and soaps as ‘chemical’ controls. But still be careful. If you invest in beneficial insects by buying them or merely encouraging them to live on your property, the oils and soaps may kill or damage them as well as the bad guys.
If your azaleas or rhodies are so decimated that they are ugly beyond belief, you may consider cutting your losses by replacing those shrub. You will then have some decisions to make. Here are the choices:
- You can choose to plant new azaleas (or rhodies). In doing so you will need to commit to providing for them them their ideal habitat and do the maintenance required to keep such habitat flourishing. This would include creating good habitat for the beneficial insects that can take care of small lace bug populations. This also might include the periodic maintenance of spraying horticultural oil or insecticidal soap. If you want new azaleas, please choose from the list of disease-resistant cultivars. But be warned that all of those cultivars are not available here in the PNW, and we’ve seen some failure with some of them already.
- You can decide the above choice involves too much work, you can choose replacement plants not munched on by lace bugs. Plants that are anything other than azaleas, rhodies, camellias, and pieris. For now, lace bugs seem only to be attaching azlaeas and rhodies in the PNW, but as you see in the UC-Davis article, there are lace bugs that eat other types of plants, too. It may be only a matter of time before we have those critters, too.
Ensure a successful landscape by:
- providing correct habitat (understanding the culture needs of the plants you are using in your landscape)
- doing suitable and timely maintenance
- employing sound integrated pest management (IPM) techniques (such as are described above)
- choosing plants that are disease and pest resistant
Please choose to employ organic, earth-friendly IPM techniques. Your grand kids and THEIR grand kids will thank you.