Common Names: Beech blight aphid
A small aphid in the order Hemiptera that feeds on the sap of American beech trees. The aphids form dense colonies on small branches and the undersides of leaves. The aphids themselves are a light bluish color with bodies covered with long, white, waxy filaments giving them a woolly appearance. They first become apparent in July and as populations continue to grow they become increasingly noticeable. Very high numbers can be seen on individual branches, sometimes extending onto leaves. Infested trees may appear to have their branches and twigs covered with snow. This aphid has a defensive behavior in that it raises the posterior end of its body and sways from side to side when disturbed. Deposits of sooty mold caused by the fungus Scorias spongiosa build up below the colonies growing on the copious amounts of honeydew the insects exude.