Acorn weevil

Systematic position. The acorn weevil (Curculio nasicus) belongs to the order Coleoptera and the family Curculionidae. It is a highly specialized species that maintains a symbiotic-like biological dependence on oak trees, functioning as a primary insect herbivore of acorn crops.

Host plants. The primary host for this beetle is the oak tree (Quercus genus). While adults may feed on leaves and buds, the most significant damage is inflicted upon the acorns, which are vital for the natural regeneration of oak woodlands and provide essential food for local wildlife.

Biology and lifecycle. The lifecycle of the acorn weevil generally spans one to two years. Adults emerge in the spring or early summer. The female utilizes her remarkably elongated rostrum to drill a hole through the pericarp of a developing acorn, where she deposits a single egg. Upon hatching, the larva consumes the interior tissues of the acorn before exiting to pupate in the soil.

Nature of damage and harm. Infested acorns often drop prematurely from the tree. The interior of the nut is hollowed out by the feeding larva and filled with frass, effectively destroying the embryo. This results in poor seed viability, which can severely impact forest reforestation efforts and decrease the availability of high-quality mast for wildlife populations.

Control measures. Integrated pest management focuses on sanitation and mechanical disruption. Key strategies include:

• Gathering and destroying infested acorns before larvae emerge into the soil.
• Tilling the soil beneath oak trees to expose pupae to predators and environmental stress.
• Applying specific insecticides to the canopy during the adult emergence period if infestations are severe.