Grape scale

The grape scale (Aulacaspis vitis) is a destructive pest belonging to the Diaspididae family. As a specialized insect, it primarily targets grapevine tissues, using its piercing-sucking mouthparts to extract vital fluids from the host plant's stems and shoots.

This pest is primarily found on Vitis species. The insects settle on the bark, often clustering together in areas that provide protection from wind and weather. Due to their coloration, which mimics the bark of the vine, they are often overlooked until the infestation reaches a critical level.

The biological life cycle of Aulacaspis vitis revolves around the production of protective scales. Females are sessile and produce eggs beneath their shields, while males are winged. The spread of the infestation occurs mainly through the movement of the first-instar nymphs, known as crawlers, which are highly mobile for a short period before finding a suitable site to settle.

Infestation damage manifests as weakened vine vigor, reduced shoot growth, and chlorotic leaves. As the insect population grows, the bark may crack, and the vine's vascular system becomes impaired. This physiological stress makes the grapevines susceptible to secondary pathogens and significantly reduces the yield and longevity of the vineyard.

Control strategies require an integrated approach. Effective management includes pruning and removing old, infested bark during the dormant season. Chemical control is most effective against the crawler stage using systemic insecticides. Furthermore, applying horticultural oils during the winter dormancy period can help smother overwintering populations and suppress early-season outbreaks.

• Pruning and mechanical removal of infested bark.
• Application of systemic insecticides during crawler activity.
• Dormant season treatments with horticultural oils.
• Enhancing vine health through proper fertilization.