Damage and nuisance


bites Calepitrimerus vitis are responsible for symptoms on the various organs of the vine.
 
  • Buds and leaves
Some buds do not bud, others grow weakly; they are stunted and eventually fall.
The leaves are smaller and show small mosaic-forming lesions visible when viewing the leaf blade through transparency (Figures 1 to 3). If the attack is severe, many of these lesions end up necrosis, eventually causing the leaves to dry out. The latter can also be curled up, pleated, or even embossed. At the level of the veins of the underside of the leaf, we can see black crusts due to the suberification of the tissues in response to the punctures.
In summer, the upper surface of attacked leaves that are exposed to the sun turns brown to tan. As veraison approaches, the shoots acquire a whitish hue due to the numerous punctures.
 
  • Twigs and branches
They grow weaker and the between nodes are shorter, giving the vines a bushy appearance.
 
  • Bunches
They develop with difficulty because they are poorly fed. They tend to turn brown, and burst. If the attack is large, an abortion of the inflorescences may occur, resulting in a significant reduction in the harvest.
The severity of the damage depends on the density of the mite population and the stage of development of the vine at the time of the attacks. The most important damage is due to the overwintering females, active during bud break, which more or less disrupt the development of the buds.
Last change : 04/20/21
Calepitrimerus_2
Figure 1
Calepitrimerus
Figure 2
Calepitrimerus_4
Figure 3