Last fall, terribly frustrated, I again typed phlox and bug into my favorite search engine and found that the Kemper Center (Missouri Botanical Garden) had a page on the Phlox Bug. The photo was a perfect match.
Here is the little pest:
and another one showing its proboscis, which he uses to suck the life out of my phlox
At the last Perennial Plant Society meeting a gardening friend and I were talking about the Phlox pilosa I had given her several years before. As conversations with gardeners go, I asked if she had been plagued by Phlox Bug and she said last summer was the first year. Another friend said she noticed the bug and damaged leaves on P. paniculata 'David'. Neither gardener seemed to know what to do.
In my garden it has only affected the summer phlox, Phlox paniculata, for which I am very grateful. It's bad enough on the tall gal but the P. pilosa is everywhere and it would be hard to treat.
From what I've read, this bug appears to be a serious problem in the Eastern US. This may seem early to start talking about this problem, but the phlox is greening up and I know I have to be vigilant. That means I will be down on hands and knees looking at the leaves with a magnifying glass if I have to!
The garden is not the same...butterflies will not be visiting here if there is no summer phlox. Have any of you experienced this problem and what did you do to solve it?
The True Bug* Story Summarized by the Kemper Center staff:
I don't usually copy and paste from other sites, so I hope you don't mind that I did this time. When it's factual info like this, how could I improve on the writing? Thank you, Kemper Center staff. I miss my phlox, I am hoping it revives. The italicized comments are mine!
Symptoms and Diagnosis
The phlox bug’s feeding causes white or light green spots on the leaves and buds that later show yellow stippling. The leaves then turn brown, curl, dry out and drop. The plant may become stunted and die. The bug feeds on leaves, stem terminals, flowers and seeds. It may be hard to see because it hides on the underside of leaves. It's true they move fast and disappear when ever there is movement near by.
The phlox bug overwinters in the egg stage in dead phlox stems. It has two generations per year. The first generation appears in late spring, the second in mid to late summer. It undergoes incomplete metamorphosis. As if one generation wasn't enough. Here is the best reason to clean out the garden bed every fall! I often waited until spring.
Integrated Pest Management Strategies
1. Practice good sanitation. Cut back and dispose of badly infested stems and leaves. Clean up stem and leaf litter in the winter. I cut back every stem I could find and threw them in the trash.
2. Scout for nymphs and treat. Apply insecticidal soap to both the upper and underside of the leaves. Use a light horticultural or sunspray oil. I look everyday for signs of infestation, so far nothing....but I am not convinced that they are gone.
3. Use chemical controls if warranted. Products listed for use include pyrethrins, permethrin or acephate/orthene, a systemic. I am hoping that being vigilant and catching the bug early means I won't have to use these bigger guns.
and one last photo of the Phlox bug and the damage it does: