Hollyhock weevil

Systematic position: The Hollyhock weevil (Apion longirostre) is a member of the Coleoptera order and the Apionidae family. It is a highly specialized insect that specifically targets plants within the Malvaceae family, often causing significant losses in seed production.

Host plants: This pest primarily affects species of the genus Alcea (hollyhocks) and Althaea (marshmallows). In agricultural settings, it is a major concern for seed growers producing ornamental or medicinal cultivars, as the damage directly impacts the final crop yield.

Biology and lifecycle: Adults hibernate in plant debris or the topsoil layer. As temperatures rise in spring, they emerge to feed on young foliage and buds. After mating, females bore into the developing fruits to deposit eggs. The larvae hatch inside the seeds and complete their entire development within the seed coat, feeding on the endosperm and embryo.

Damage characteristics: The primary economic damage is caused by the larvae, which destroy the seed contents. This often goes unnoticed until harvest, as the outer appearance of the fruit may remain relatively intact. Heavily infested batches exhibit significantly reduced germination rates, rendering the seed unsuitable for further cultivation or sale.

Control measures: Management of Apion longirostre requires an integrated approach to break the pest's lifecycle:

• Removal and destruction of wild Malvaceae weeds that serve as alternative hosts.
• Autumn soil tillage to disturb and kill overwintering adult populations.
• Application of targeted insecticides during the pre-flowering and flowering stages, synchronized with the adult activity period.
• Monitoring for oviposition sites and signs of early infestation on developing seed pods.