How to Manage Pests

Pest identification and confirmation—Taphrina

Blisters caused by Taphrina fungi may look similar to those caused by the live oak erineum mite. Mites cause blistered leaves or galled twigs and occur in yellow to orange felty masses in depressions on the underside of blistered leaves. No felty masses of mites are found on the undersides of leaves infected with Taphrina spp. However, Taphrina produces masses of pale spores on leaf surfaces that resemble the felty mass caused by erineum mites. Taphrina spores (asci) can occur on either leaf surface; the felty colonies of erineum mites usually occur only on the undersides of oak leaves. Microscopic examination may be required to distinguish confidently between erineum mites and Taphrina spores. The minute eriophyid mites can barely be seen with a 10X hand lens. A dissecting binocular microscope is required to determine clearly whether eriophyid mites are present.

Blisters caused by the Taphrina fungus

Live oak erineum mite feeding damage