My canada goldenrod is getting attacked by some kind of lace bug this year. There are so many lace bugs they cover teh leaves. My yarrow and my white old-field asters are also affected, which makes me think that the lace bug is able to feed upon a variety of Asteraceae, but a lot of my asteraceae are unaffected.
In fact, the plants seem to be getting attacked in proportion to how numerous they are. The canada goldenrod and white asters, which are everywhere, are stunted and their leaves are yellow and curling up and turning brown. But the weird goldenrod (a goldenrod I have that is different from all the other goldenrods in a way I have never been able to identify) is totally unaffected. The purple coneflowers don't seem affected. Cup-plants seem okay. The ashy sunflowers have some lace bugs on them, but they don't appear to have ill effects.
Why would the lace bug feeding be focused on the most populous species? Maybe yarrow, canada goldenrod and white oldfield aster secretly have their own lace bug species that can only exist at a certain population level of the host plant? Or maybe they only attack plants with large populations?
Or maybe different populations of a species prefer different host plants, even if they aren't the same species?
Weird...
I am watching this happen with curiosity because the goldenrod was actually overpopulated to the point that it was overtaking a lot of my other plants. The lace bugs seem to have beaten back the goldenrod a lot and allowed other things to grow and succeed better.
Plants in the same family with much lower populations are not being attacked to the same extent. That's the weird part.
It seems to have the effect of re-balancing the population...but why?





















