The apple blossom weevil, scientifically known as Anthonomus pomorum , is a dreaded pest of orchards. This weevil mainly attacks apple trees and sometimes pear trees. It causes significant damage to flower buds and, consequently, to fruit production. Its presence is feared by arboriculturists because it can compromise flowering and reduce yields, especially when spring weather conditions are conducive to its proliferation. In this article, we explore this pest in depth and the effective methods developed by Agrobiotop to control it.
Introduction to the apple blossom weevil
| Common noun | Apple blossom weevil |
| Scientific name | Anthonomus pomorum |
| Order | Beetle |
| Family | Weevils |
| Targeted plants | Apple tree ( Malus domestica ) |
| Distribution | Europe, Middle East, North America |
How to identify the apple blossom weevil?
The adult apple weevil is a blackish-grey weevil , up to 6 mm long. It has a thin, elongated rostrum and a whitish V-shaped band on its back, accompanied by a white dot between the thorax and the elytra.
The larva, meanwhile, develops inside the buds. It is whitish to yellowish , legless, and its head is black. At the end of growth, it can reach up to 8 mm long.
The nymph is pale yellow in color.
Do you need a solution against the apple blossom weevil?
Life cycle of the apple blossom weevil
From July onwards, adults enter diapause and take refuge in various natural shelters, such as under the bark of apple trees or in dead leaves, where they remain until the end of winter.
At the end of winter, between the end of February and March , when temperatures reach an average of 9 °C, adults come out of diapause. They then feed on a few buds before mating, about ten to fifteen days after their reactivation.
After mating, the female lays approximately 25 eggs, each of which is placed in a flower bud that is just beginning to swell. The eggs hatch eight days later, giving rise to larvae that remain inside the buds, where they feed on the reproductive organs and inner petals, preventing flowering.
After about three weeks, the larva pupates before becoming an adult . These new adults emerge between the end of May and July. During the summer, they feed on the leaves for about fifteen days before entering summer diapause again, thus completing their cycle.
What damage does the apple blossom weevil cause?
Damage caused by the apple blossom weevil is most visible in flower buds , mainly on apple trees and sometimes on pear trees.
The larvae destroy the interior of the buds by feeding on the ovaries, stamens and petals , thus preventing flowering and fruit formation.
Affected buds take on a characteristic appearance, drying out, turning brown, and becoming similar to a ” clove “. This deformation of the buds is one of the first signs of an infestation by the weevil.
Adults can also damage young fruit , which can lead to minor deformation or post-harvest rot.
What methods of prevention against the apple tree weevil?
To combat the apple tree weevil, certain prevention practices can be implemented. In particular, we recommend that you favor natural predators . Encourage the presence of insectivorous birds such as sparrows, tits and goldfinches by installing nest boxes in the orchard. These birds feed on adults and weevil larvae.
