Acorn moth

Systematic position: The Acorn moth, Cydia splendana, belongs to the order Lepidoptera and the family Tortricidae. It is a significant forest pest that specifically targets the fruit of oak trees, acting as a primary biological factor in seed loss within deciduous forest ecosystems across Europe and parts of Asia.

Host plants: The primary host for this species is the acorn of various oak species (genus Quercus). Occasionally, the larvae can be found infesting the nuts of sweet chestnut (Castanea sativa) and sometimes walnut, but the insect is most notorious for its impact on oak regeneration.

Biology and life cycle: Cydia splendana is univoltine, meaning it produces only one generation per year. The insect overwinters as a mature larva in a cocoon located within the soil or leaf litter. Pupation occurs in the spring, and adult moths emerge during the summer months, with their flight activity synchronized with the development of the acorn crop.

Damage and economic impact: The damage is caused by the larvae, which burrow into the acorns and consume the cotyledons. This feeding activity not only destroys the embryo of the seed, rendering it infertile, but also creates entry points for fungal pathogens, leading to the rapid decay of the infested fruit and significant forest regeneration failure.

Control measures: Management of the Acorn moth is focused on minimizing larval populations in silvicultural settings. Strategies include the early removal and destruction of fallen infested acorns to disrupt the life cycle. Additionally, soil cultivation in late autumn or early spring can expose overwintering larvae to predators and environmental stress, while targeted insecticide treatments may be used in nurseries.