Chestnut phylloxera

Taxonomic position: The chestnut phylloxera (Phylloxera castaneae) belongs to the order Hemiptera and the family Phylloxeridae. It is a specialized sap-sucking pest that has evolved to feed specifically on species of the genus Castanea, inducing the formation of characteristic leaf galls.

Host plants: The primary host of this pest is the sweet chestnut (Castanea sativa). Depending on the geographical range, it can also infest other chestnut species found in natural forests, parks, and industrial orchards, causing significant stress to the host plants during active growth stages.

Biology and life cycle: The life cycle of this insect involves several distinct generations. Typically, it overwinters as eggs tucked into the crevices of tree bark. In early spring, the founding nymphs emerge and migrate to the developing leaves. By feeding on the leaf tissue, they trigger the plant to produce galls, which provide a protected environment for the insects to develop throughout their life cycle.

Nature of damage and economic impact: The presence of the pest is indicated by numerous small galls on the underside of the leaves, which appear as yellowish or brownish spots on the upper surface. Heavy infestations interfere with photosynthesis, leading to early leaf yellowing and premature defoliation. This reduces annual growth, weakens the trees, and increases their susceptibility to secondary pathogens and climate stress.

• Conducting regular crown monitoring during the spring and summer.
• Performing sanitary pruning of heavily infested branches to reduce local populations.
• Applying systemic insecticides during the peak periods of nymph emergence.
• Implementing strict quarantine protocols for imported plant material.
• Promoting overall tree vigor through proper fertilization and irrigation practices.