Raspberry leaf gall mite

Systematic position: The raspberry leaf gall mite (Acalitus odoratus) belongs to the order Trombidiformes and the family Eriophyidae. As a microscopic pest, it is highly specialized, living and feeding exclusively within the tissues of various species of the genus Rubus, causing distinct pathological changes in the plant architecture.

Host plants: The primary host is the raspberry plant. The mite prefers young, rapidly growing foliage and tender shoots. When the infestation is severe, the mite can colonize a significant portion of the plant, severely compromising the physiological health of the canes and drastically reducing the quality and quantity of the harvest.

Biology and life cycle: The mites overwinter as adult females under the bud scales. When the temperatures rise in spring, they migrate to the developing leaves to begin feeding. The life cycle is quite short, allowing for multiple overlapping generations throughout the summer months, which explains why populations can reach such high levels within a single season.

Nature of damage: The presence of the mite induces the formation of galls, which are localized swellings on the leaf surface. These galls are typically covered with a dense, felt-like mass of trichomes, which initially appear white or yellow before turning brown. Heavily infested leaves become curled, brittle, and distorted, ultimately inhibiting the plant's photosynthetic capacity.

• Conduct strict sanitary pruning in late autumn to remove and destroy infested canes.
• Only introduce new stock from nurseries that guarantee pest-free, certified material.
• Apply targeted acaricides during the early stages of bud break when mites are most exposed.
• Maintain optimal plant spacing to ensure good air circulation and reduce microclimate favorability.
• Monitor the undersides of leaves regularly during the growing season for early signs of felt-like growth.