Nut weevil

Conotrachelus neomexicanus is a species of beetle belonging to the order Coleoptera and the family Curculionidae (weevils). This insect is recognized as a specific pest that targets various nut-bearing trees, significantly affecting the yield and quality of nut production in affected regions.

The primary host plants for this pest include walnut and hickory species. The beetle infestation usually begins when female adults pierce the developing fruit to oviposit. The subsequent feeding by larvae inside the nuts causes them to become hollow, necrotic, and eventually drop prematurely from the tree.

The biological cycle of Conotrachelus neomexicanus is synchronized with the phenology of the host tree. After the larvae complete their feeding phase within the nut, they exit and burrow into the soil to pupate. The overwintering stage typically occurs in the soil or under leaf litter, allowing the insect to survive unfavorable environmental conditions.

Damage caused by this weevil is often characterized by surface punctures and internal tissue decay. Secondary infections by fungi and bacteria frequently colonize the damaged nuts, rendering them entirely unfit for market. High population densities can result in severe economic losses if left unmanaged throughout the season.

Integrated pest management (IPM) is essential for controlling this weevil. Key strategies include:

• Sanitation by removing and destroying fallen, infested nuts.
• Cultivation of the soil under the tree canopy to disrupt the pupation process.
• Use of targeted insecticides applied during the peak emergence of adults.
• Regular scouting and monitoring using traps to determine the timing of chemical interventions.