Lime nail gall mite

The lime nail gall mite (Eriophyes tiliae) belongs to the family Eriophyidae, which are microscopic plant-feeding mites. These pests are widely recognized for the distinct nail-shaped galls they induce on the foliage of lime trees (Tilia species), making them a common sight in urban landscaping and forests.

The host range of this mite is specifically limited to the Tilia genus. While it does not typically cause tree mortality, its presence can significantly alter the appearance of the foliage, leading to widespread concern among arborists and gardeners during the mid-summer months.

The biological cycle begins in the spring when overwintered adult females emerge from crevices in the bark or bud scales. They move to the newly expanding leaves to feed. Through the injection of salivary secretions, they stimulate the leaf tissue to grow abnormally, creating a chamber known as a gall, inside which the mite feeds and reproduces throughout the season.

The damage is primarily aesthetic, manifested as numerous erect, cylindrical, or spike-like galls on the upper leaf surface. While these galls might look alarming, they rarely cause severe systemic damage unless the tree is already stressed or the infestation is exceptionally heavy, which can lead to premature leaf drop or reduced growth.

Managing Eriophyes tiliae requires observation and timely intervention. Chemical control with acaricides is only effective if applied early in the season when mites are moving onto the leaves. Often, however, because the damage is largely superficial, natural predators and the physical removal of heavily infested leaves during the autumn serve as sufficient control measures to maintain tree health.