Azaleae bark scale

The azaleae bark scale, Eriococcus azaleae Comstock, can be found on a variety of hosts grown in nurseries and landscapes including azaleae, rhododendron, andromeda, hawthorn, poplar, willow, and most recently, it has been found infesting blueberries in the Pacific northwest. It can be found on bark and stems and has a woolly or cottony appearance.

It is reported to have one generation a year in Connecticut but may have two generations in warmer climates such as the south. The overwintering females lay eggs under the scale in the spring. The eggs hatch in the late spring/early summer and the young crawlers disperse and soon settle, mostly in bark crevices, branch crotches, and but also onto new growth and leaves. In 2006 crawlers were captured on double-sided sticky tape place on June 9 and read on June 12.

Azaleae bark scale on blueberry

Photo: Wei Yang

Azaleae bark scale on blueberry closeup

Photo: USDA-Natural Resources Conservation Service.

Azaleae bark scale in leaf axil

Photo: Rosetta

Exposed eggs under scale shell

Photo: Joe DeFrancesco

Closeup of scale eggs

Photo: Rosetta

Closeup of scale eggs

Photo: Rosetta

Double-sided sticky tape with crawlers (note large numbers of crawlers near arrows)
Photo: Rosetta

Double-sided sticky tape with crawlers

Photo: Rosetta

Close-up of crawlers

Photo: Rosetta

Close-up of crawler stuck in tape

Photo: Rosetta

Page last modified 7/6/06