Grape rust mite

Taxonomic position: Calepitrimerus cerosus is a member of the class Arachnida, order Trombidiformes, and family Eriophyidae (gall or rust mites). As a microscopic pest, it is specialized in feeding on the green tissues of grapevines, often going unnoticed until significant damage to the plant physiology occurs.

Host plants: The primary host for this mite is the common grapevine (Vitis vinifera) and its various cultivars. The mite exhibits a strong preference for tender, rapidly growing tissues such as young leaves, buds, and floral clusters, significantly impacting the vine's development.

Biology and life cycle: The mites overwinter as fertilized females, primarily hiding under the bark scales or within the bud scales of the canes. As temperatures rise in spring, they emerge to infest newly developing foliage. Throughout the growing season, the mite undergoes multiple generations, with population density increasing rapidly under favorable climatic conditions.

Damage and economic impact: Infestation manifests as leaf curling, chlorotic spots, and general stunted growth of the grapevine shoots. Feeding activity can lead to premature shedding of flower buds and reduced photosynthetic capacity, which compromises the sugar accumulation in berries and weakens the vine's overall resistance to environmental stress.

Control measures: Management strategies rely on an integrated approach, including cultural practices like pruning and removal of infested vegetative parts during winter. Chemical control involves the application of specialized acaricides during the critical spring period when the mites migrate to new growth. Monitoring programs are essential to determine the infestation threshold before applying targeted treatments.