You’ve seen ’em while outside, you’ve thought they were dirt or fuzz or dust, but they aren’t and they are invading Knoxville, Tennessee. They are the Asian wooly hackberry aphid or commonly called the white aphid.
This time of year the temperatures and moisture levels are just right to support a population boom. You’ve probably seen the black moldy looking substance they leave behind on your car or on the leaves of certain trees. That’s known as sooty mold, and it’s a fungi that grows in the substrate left behind by the aphids. They suck the sap out of the leaves and don’t digest all of it. So some of that sugary substrate then floats and settles underneath the certain trees.
Sadly there is not an aphid spray to keep them off you like mosquito spray, but these insects won’t be sticking around for long. Once we see our first frost, they should disappear.