Rhododendron (Rhododendron)-Azalea bark scale

Eriococcus azaleae

See:

Common Pests of Nursery Crops

Pest description and crop damage White, cottony sacs enclosing small, reddish eggs.

Management-chemical control

See:

Chemical Control of Nursery Pests

For more information

Johnson, W.T. and H.H. Lyon (1991), Insects That Feed on Trees and Shrubs, 2nd ed., Cornell University Press (p. 336).

PNW Nursery IPM: Azalea Bark Scale (http://oregonstate.edu/dept/nurspest/azalea_bark_scale.htm)