Mexican rose beetle

Systematic position. The Mexican rose beetle (Macrodactylus mexicanus) belongs to the order Coleoptera and the family Scarabaeidae. This agricultural pest is primarily distributed across Mexico and Central America, where it poses a significant threat to various crops by engaging in massive feeding aggregations.

Host crops and damage. As a polyphagous insect, it infests maize, legumes, fruit trees, and ornamental plants. Adult beetles feed voraciously on foliage, consuming everything except the veins, and attack reproductive structures such as flowers and silks. This leads to severe yield losses and degraded quality of agricultural harvests.

Biology and life cycle. The life cycle consists of egg, larval, pupal, and adult stages. Larvae reside in the soil, feeding on organic matter and plant roots. Adult beetles emerge in high numbers during the flowering stage of host crops, forming dense swarms that can quickly overwhelm a field, leading to rapid and widespread plant destruction.

Nature of injury. The primary form of damage is skeletonization of the leaves, which inhibits the plant's ability to photosynthesize effectively. In severe cases, the beetles target the developing reproductive parts, which can lead to total crop failure, particularly in sensitive stages of grain development, necessitating urgent intervention.

Control measures. Effective management of Macrodactylus mexicanus relies on an integrated approach combining mechanical, biological, and chemical strategies:

• Deep tillage during the off-season to disrupt the larval environment.
• Crop rotation to reduce the availability of preferred host plants.
• Application of targeted systemic insecticides based on economic thresholds.
• Monitoring adult beetle activity using light or pheromone traps to time interventions correctly.