Cherry gall mite

Systematic position. The cherry gall mite (Rhinotergum cerasifoliae) belongs to the order Trombidiformes and the family Eriophyidae. These are microscopic plant-feeding mites characterized by their worm-like bodies and the ability to induce abnormal cell growth in host plants.

Host plants and damage type. The primary hosts for this pest are species within the genus Prunus, specifically sweet and sour cherries. The mites feed by piercing the plant cells, which triggers the formation of galls — irregular growths on the leaf surface. This activity interferes with regular leaf development and metabolic processes.

Biology and life cycle. These mites overwinter as fertilized females in protected niches such as bud scales or bark crevices. As soon as temperatures rise and buds begin to swell in spring, the mites migrate to the young emerging foliage. They produce multiple overlapping generations throughout the growing season, rapidly increasing their population size.

Economic impact. Heavy infestations result in severe leaf deformation, curling, and early senescence. Such damage significantly reduces the tree's photosynthetic capacity, leading to decreased winter hardiness and reduced fruit yield in subsequent years. Young trees and nursery stock are particularly susceptible and may show stunted growth.

Control measures. Management requires the timely application of acaricides, specifically targeting the period between bud burst and leaf unfolding. Integrated pest management strategies also include pruning infested branches and maintaining tree vigor through proper irrigation and fertilization, which helps the plants tolerate mite-induced stress.