Linden felt scale

The linden felt scale (Acanthococcus insignis) is a scale insect belonging to the family Eriococcidae. It is a significant pest primarily affecting linden (Tilia) species, where it feeds on plant sap, leading to stunted growth and weakened vitality of the host tree.

The biological cycle of this insect includes one generation per year. The overwintering stage consists of second-instar nymphs that hide in the crevices of bark or near buds. As spring temperatures rise, these nymphs migrate to young shoots and leaves, where they undergo development, eventually molting into adults.

Damage caused by the linden felt scale is characterized by deformation of new shoots and leaves. The insect injects toxins while feeding, which results in the formation of galls and twisted, stunted growth. In cases of high infestation, the foliage may turn yellow prematurely and drop, leading to dieback of small branches.

The presence of the pest is most easily identified by the white, cotton-like ovisacs produced by females. These structures protect the eggs and are visible on the bark and twigs. Monitoring these signs in late spring and early summer is crucial for implementing timely and effective management strategies.

• Pruning and destroying heavily infested branches to reduce population density.
• Applying systemic insecticides during the peak of nymph emergence.
• Using horticultural oils during the dormant season to target overwintering stages.
• Promoting healthy tree growth through proper irrigation and soil management.