Apple curculio

Systematic position: Anthonomus quadrigibbus is a coleopteran insect belonging to the Curculionidae family, commonly known as the apple curculio. It is a well-documented pest in horticulture, particularly recognized for its ability to cause severe economic losses in pomaceous fruit production by targeting reproductive structures.

Host plants: The primary hosts include apple and pear trees, though the pest also infests hawthorn, quince, and occasionally other rosaceous plants. The preference for specific fruit development stages makes this weevil a targeted threat to the orchard's productivity during the critical window of fruit setting and early growth.

Biology and life cycle: The adult weevil overwinters in protected sites such as bark crevices or leaf litter. As temperatures rise in early spring, adults emerge to feed on developing buds. The female uses its rostrum to drill a hole in the young fruit or bud to oviposit. The larva completes its development inside the fruit, feeding on the tissue, and eventually pupates within the infested fruit.

Damage and severity: The most characteristic damage is the malformation of fruit. As the larva consumes the interior, the affected area stops growing, resulting in a distorted, lumpy, or pitted fruit shape at harvest. Furthermore, premature fruit drop is a common consequence of severe infestations, which can lead to a drastic reduction in commercial yield.

Protection measures: Integrated pest management (IPM) is essential for controlling Anthonomus quadrigibbus. Key strategies include:

• Regular monitoring using visual inspections during the budding phase.
• Sanitation, including the collection and destruction of infested fallen fruit to break the life cycle.
• Application of selective insecticides during the pre-bloom and post-bloom periods.
• Manual removal of old bark and maintenance of healthy orchard surroundings.