New Bartlett Pear tree with wierd leaves

Asked April 27, 2018, 11:33 AM EDT

just purchased and planted this new flowering Pear Tree and noticed something odd on many of the leaves? HELP

Linn County Oregon

1 Response

Sorry to learn that your tree has challenges so early in its life at your place. Thank you for including the nice images which clearly reveal that the leaves are affected by pear leaf blister mites. Judging by the numerous inquiries Ask an Expert has received about pear leaves, this is a particularly bad year for these mites. Treatment is effective only when applied in fall and early spring.

Pear leaf blister mites are sometimes referred to as pear rust mites. They are eriophyid mites and are far different than the spider mites you may be familiar with. Spider mites are about a 32nd of an inch, somewhat oval, and have 8 legs. Pear leaf blister mites are smaller, elongated (similar to a worm), and have only 4 legs.

Blister mites survive the winter under the scales surrounding the leaf buds where they begin feeding before bloom. Feeding causes reddened raised areas on the leaves which, with time, become brown. The mites may also feed on the fruit’s skin.

Home gardeners can decrease the mite populations by applying lime sulfur in the fall. (Unfortunately, lime sulfur may be difficult to locate in small packaging suited for home garden use.) In the spring, prior to bud swell, either repeat the lime sulfur or use superior oil. Follow label directions as to the dilution rate.