Alder sucker

Systematic position: The Alder sucker (Psylla praevia) belongs to the order Hemiptera and the family Psyllidae. This insect is a specialized pest that maintains a close biological relationship with trees of the genus Alnus (alder).

Host plants: The primary hosts are various species of alder, specifically grey alder and black alder. It is a common inhabitant of alder forests, shelterbelts, and specialized nurseries, where its feeding activity can impact the health of young saplings.

Biology and life cycle: The insect follows a hemimetabolous life cycle. Adults overwinter in protected locations such as bark crevices or within leaf litter. When spring temperatures rise, the adults emerge, feed on developing buds, and lay eggs, ensuring that nymphs have immediate access to nutrients upon hatching.

Nature of damage: Both nymphs and adults are sap-suckers. They pierce the leaf tissue, which often leads to foliage curling, chlorosis, and premature senescence. The weakened trees may exhibit reduced annual growth rates and increased susceptibility to secondary infections and environmental stressors.

• Proper maintenance of forest sanitation by removing debris.
• Conservation of natural predators such as ladybirds and lacewings.
• Application of systemic insecticides during critical development stages.
• Regular field monitoring to detect early infestation signs.

Control measures: Effective management relies on an integrated pest management (IPM) strategy. In high-value forestry areas, chemical treatments should be timed precisely to coincide with the susceptible developmental stages of the insect. Promoting biodiversity in the forest ecosystem helps maintain natural populations of beneficial predators, which often keep pest numbers below economic thresholds.