Damage and nuisance
The first reports of damage by Eotetranychus carpini berry moths on vines in 1954 correspond to the period of generalization of the use of synthetic insecticide products against grape .
This yellow-colored mite is commonly referred to as a “ yellow spider ”. Its many nutritional bites cause symptoms on the leaves that are very different from those induced by the other vine mite Panonychus ulmi .
The drying out of the young shoots spring or sagging inflorescences may occur early in the season, following the early overwintering females activity. The damage is particularly severe when the climatic conditions are unfavorable to vegetative growth.
At the beginning of summer, when the twigs stop growing, the mite populations concentrate under the foliage, and they then weave numerous webs to ensure their protection. The mobile forms, carrying out numerous nutritional punctures, cause discolorations of the lamina which can take a yellow to red tint, or be more or less "mosaic" (figures 1 to 4). The presence of necrotic areas, very visible and characteristic, give an autumnal aspect to the leaves at the origin of the name of the disease: "red vine disease".
It should be noted that these various symptoms are at the origin of bad ripening of the vine shoots, an early fall of the leaves and a decrease in the sugar content of the grapes.