Plum curculio (Rhynchites cupreus)

Rhynchites cupreus, commonly known in its ecological niche as a stone fruit weevil, belongs to the family Attelabidae. It is a specialized pest that targets stone fruit trees, posing a significant risk to fruit production by damaging the developing ovaries.

The primary hosts of this weevil are stone fruit trees such as plums, cherries, apricots, and peaches. It can also infest other species like rowan. The pest is particularly aggressive during the initial phases of fruit set, often leading to severe yield losses if left uncontrolled.

The life cycle involves overwintering as adults in the soil. As temperatures rise in spring, they emerge to feed on developing buds and young fruits. A critical part of their reproductive behavior involves the female depositing eggs into the fruit and then severing the fruit stalk, causing the fruit to fall to the ground prematurely, where the larva feeds on the seed.

The damage caused by Rhynchites cupreus is twofold: direct feeding damage to buds and ovaries, and the induced fruit drop caused by the female's oviposition process. Since the larvae complete their development inside the fallen fruit, the entire seed portion is typically destroyed, leaving no chance for the fruit to mature.

• Strict sanitation by removing and destroying all fallen fruit (drops).
• Tillage of the soil beneath the canopy to disturb overwintering larvae and pupae.
• Application of appropriate insecticides during the post-flowering period.
• Mechanical control via shaking trees onto sheets during cool morning hours.