Life cycle, population dynamics

• The hibernation of Eotetranychus carpini is in the form of overwintering females mated. these are bright yellow in color, located under the bark of old wood, and grouped in colonies. They quickly resume their nutritive activity as soon as warmer conditions return in early spring (their minimum thermal threshold being 7 ° C), as well as egg laying. The number of eggs laid increases with temperature and is maximum between 26 and 30 ° C.
• From the hatching, 7 stages will follow one another, including the first larval stage which is hexapod. Note that the larvae are more greenish in color than the adults. The duration of a cycle from egg to adult is 28 days at 15 ° C, so after bud break all stages of development are quickly present on the vine. At the end of the season, we can count from 4 to 9 successive generations.
• From August, the wintering females appear. They are distinguished by their more vivid coloring within the colonies. They will descend to the old wood of the vine before the leaves fall.
• Critical periods are observed during bud break and during summer. Outside these periods, the growth of the twigs leads to a dilution of the individuals in the vegetation. Mobile forms can greatly exceed one hundred individuals of all stages per leaf. These conditions of pullulation are encountered:
  • in the absence of predatory mites Typhlodromes;
  • in the case of insecticide-acaricide resistance phenomena;
  • in the case of strong vines vigor.

Note : this mite is only observed on the underside of leaves.