Description, Biology, Life Cycle, Damage, Common Names, Images
- Host plants: apple, pear.
- The mites migrate from their hibernation site towards flower buds. They feed firstly upon green scales and the tips of rolled leaves, later colonizing petioles, flower stems and sepals.
- Fruit buds are attacked as soon as they begin to swell and the scales begin to open. Thereafter, the mites develop preferentially on the underside of leaves (*) , but if they are particularly abundant, they may also be found on the upper surface.
- The total fecundity of protogynae is 67 to 102 eggs laid over several days, while deutogynae produce 21 to 47 eggs.
- Deutogynae move to their hibernation site between July and September, depending on the state of foliage. When they hibernate on one-year-old shoots, they are in close proximity to fruit buds which will thus be attacked early. When they hibernate under the bark of spurs, they are further from flower buds which will thus be attacked later.
- The eggs are laid on the green parts of fruits and on fruit buds. They begin to hatch in May and give rise to a generation of protogynae and males, which are mature from the end of May. Populations grow very slowly during May, then more rapidly as the temperature rises, to reach a peak of more than 500 individuals per leaf by the end of August. In May, the deutogynae die and, for several weeks, the colonies contain only protogynae. At the end of June, deutogynae reappear and their numbers increase until the end of the season.
- Length of cycle = 39 days at 10°C; 16 days at 16°C; 10 days at 22°C.
The underside of heavily infested leaves becomes brown. (*) .
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