AppearanceDuring late spring and summer, tubular growths up to 5 millimetres long develop on the upper surface of lime tree leaves. These galls may be yellow-green or red in colour, may be very numerous, and predominantly occur on the lower leaves in some sub-species.
BehaviorThe mites move onto the foliage in the spring, having overwintered in the bark crevices or around buds. These gall inducers are less than 0.2 mm long, however the chemicals they release whilst sucking the sap from the lower leaf epidermis have a dramatic, consistent and colourful effect, causing upward growing, hollow, yellow, red or pink, finger-like extensions. Before the autumn, the mites, which up to now have been actively feeding and growing inside the galls, depart from these shielings and seek sheltered and protected sites on the lime tree. The mites will pass the winter in such locations and then the cycle will be repeated. This species is one amongst a number of gall-formers which can be superficially similar in appearance; however ''E. tilae tilae'' is restricted to lime trees.
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