Hawthorn treehopper

The hawthorn treehopper (Glossonotus crataegi) is a specialized insect belonging to the Membracidae family, within the order Hemiptera. These insects are easily recognized by their highly developed pronotum, which extends back over the abdomen and forms a distinct hump that mimics thorns or galls on the host plant, providing effective camouflage.

These pests primarily target members of the Rosaceae family. Their preferred host plants include hawthorn, apple, pear, plum, and occasionally oak trees. They are most commonly found in neglected orchards, hedgerows, and mixed woodlands where diverse tree species provide stable conditions for their development throughout the season.

The life cycle involves incomplete metamorphosis. They typically overwinter in the egg stage, with females inserting eggs into small slits in the bark of young twigs. In the spring, nymphs emerge and begin feeding on the sap of the tree. As they mature, they progress through several instars before becoming winged adults, which are capable of flight and dispersal to neighboring branches.

Damage is caused by both nymphs and adults feeding on the phloem of young branches. This sap-feeding behavior leads to physiological stress, reduced vigor, and distorted growth of shoots. Furthermore, the oviposition sites (where eggs are laid) create wounds in the bark that are highly susceptible to secondary infections by pathogens, such as fungi or bacterial cankers.

Managing the hawthorn treehopper requires a combination of cultural and chemical interventions. Key strategies include:

• Regular dormant pruning to remove heavily infested twigs and destroy overwintering eggs.
• Monitoring for nymph activity during the early spring to apply targeted insecticide sprays.
• Maintaining tree health through proper fertilization and watering to improve tolerance against sap-sucking insects.
• Cleaning trunks of loose bark to reduce the available sites for colonization.