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Yellow spider mite
The spider mite is a pest derived from the mite Tetranychus urticae Koch. The female adults of this mite hibernate in the vine’s trunk, in fallen leaves and in infesters. However, another part of the population may remain active (feeding and breeding) in infesters. Before budding, the females move to the infesters, join the population that stayed there during winter, and lay eggs. After budding, the mites move to the vines and colonise the leaves from the bottom to the shoots’ ends.
Leaves:
- Yellow spots that evolve to continuous necroses and may result in early defoliation.
Other elements of the grapevine:
- The yellow spider mite also attacks shoots, tendrils and bunches (they weave webs that cover the grapes with grey spots).
Cultural control:
Special attention should be paid to infesters, particularly when they dry (due to intervention or lack of water). After 8 to 10 days, one should estimate the risk.
Biological control:
If the vine has phytoseiid populations, the treatment programme should be adapted to use pesticides not very toxic to predators. When the vine does not have predators, one can carry out inoculative releases of populations collected from other vines.
Chemical control:
Winter Treatment:
- Summer Oil
- malathion + Summer Oil
Spring / Summer Treatment:
- cyhexatin
- dicofol
- fenpyroximate
- summer oil |
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