Beech blight aphid (Porciphilus imbricator)
Woolly beech aphid (Phyllaphis fagi)
Pest description and damage Several species of aphids can become problems on beech. Both species are woolly aphids. Beech blight aphid forms masses of bluish-white woolly aphids on the undersides of stems, sometimes causing the death of twigs, small branches and even young trees. The woolly beech aphid is especially common on the undersides of purple leaf beeches. The aphid is greenish with prominent long waxy strands. It is said to be under control of natural enemies, but if pesticide practices have upset the balance, aphid populations may soar.
For biology, life history, monitoring and management
See "Aphid" in:
For more information
Rosetta, R. 2010. Woolly beech aphid (http://oregonstate.edu/dept/nurspest/woollybeechaphid.htm)