Entomology: Landscape Pest Management: Insect ID : Ornamentals

Adults of these two eriophyid mites are not visible without a hand lens. They live in circular and spindle-shaped galls. They are white to clear in color, 0.15 mm long, cigar-shaped with only four anterior legs. There are several generations a year. Adult forms overwinter in bark cracks.
Control measures usually are not necessary in the landscape. Pyrethroid application when leaves first flush may prevent new galls.