These aphids also secrete pale wax, which covers their bodies. Woolly aphids on shoot terminals and leaves appear as fuzzy, bluish or white masses, each about 1/10 inch or less in diameter. Winged forms have distinct black borders along the forewing veins and their antennae have alternating dark and light bands.
If you have a hackberry tree and are finding copious amounts of honeydew, confirm that these aphids and not the citricola scale, another pest of hackberries, are the cause before taking any action.
Learn more about this pest in the newly revised Pest Note: Hackberry Woolly Aphid by Andrew Lawson, CSU Fresno, and Steve Dreistadt, UC IPM.