Hawthorn sucker

Taxonomic position: The hawthorn sucker (Psylla crataegi) is a member of the order Hemiptera and the family Psyllidae. This small sap-sucking insect is a common pest specialized on species within the Rosaceae family, primarily focusing on hawthorn bushes and trees.

Host plants and damage: The insect primarily targets hawthorn (Crataegus), but it can also affect neighboring fruit trees in home gardens. The primary damage is caused by nymphs and adults feeding on the sap of buds and tender young shoots. This feeding habit results in stunted growth and distorted, curled leaves that often lose their photosynthetic capacity.

Biology and lifecycle: The species typically overwinters in the egg stage, with eggs laid near the buds or within bark crevices of the host plant. Upon bud burst in early spring, the nymphs hatch and begin feeding immediately. The lifecycle involves several nymphal instars before reaching the adult stage, with the rate of development highly dependent on temperature and local moisture conditions.

Nature of damage: As the nymphs feed, they secrete large quantities of honeydew. This substance creates a sticky environment on the leaf surface, which encourages the growth of sooty mold. This black fungal growth interferes with gas exchange and photosynthesis, causing leaves to drop prematurely and weakening the overall health of the tree during the critical growing season.

Protection measures: Management strategies focus on early identification and timely insecticide application, ideally when nymphs are first observed at the bud burst stage. Proper orchard hygiene, such as pruning affected branches and ensuring adequate airflow through the canopy, helps reduce the population density. Encouraging natural predators, such as ladybirds and lacewings, is also a key component of integrated pest management.

• Monitor for early signs of leaf curling in spring.
• Apply targeted insecticides during the early nymphal stages.
• Ensure proper spacing between trees to prevent rapid pest spread.