Description
The grape mealybug (Homoptera: Pseudococcidae) has a flattened, oval pink body covered in a mealy white wax coating. It is somewhat segmented in appearance, but the divisions between head, thorax and abdomen are not distinct. Mature wingless females are about 5 mm long. They have long waxy filaments along the edge of the body that are longest at the rear and become progressively shorter toward the front end. Large numbers of eggs are laid in cottony masses. The smaller, winged males have a pair of long, white anal filaments. Yellow to brown crawlers that emerge from the oval, orange eggs are not covered in wax. All stages are mobile.
Damage
Damage is similar to that for soft scale. Plant sap is removed during feeding and large amounts of honeydew foul the fruit and promote the growth of sooty mold fungus. Most fruit damage occurs during the development of the second brood in late summer. Mealybugs can infest grape bunches and are known to transmit certain strains of leafroll virus.
Lifecycle
Females move in late fall to old wood and lay overwintering eggs in cottony egg masses under loose bark. Crawlers, some of which might have hatched in fall and remained dormant throughout the winter, move to new shoots in spring. Grape mealybugs mature and produce a 2nd generation that matures in late autumn. They can occur on all plant parts but are more common in summer on leaves and new growth, usually hidden within the canopy.
Damage is similar to that for soft scale. Plant sap is removed during feeding and large amounts of honeydew foul the fruit and promote the growth of sooty mold fungus. Most fruit damage occurs during the development of the second brood in late summer. Mealybugs can infest grape bunches and are known to transmit certain strains of leafroll virus.
