Ash weevil

Systematic position and description. Myllocerus pustulatus is a beetle species belonging to the order Coleoptera and the family Curculionidae (true weevils). The adults are characterized by a distinct rostrum and a body covered with scales, which provide cryptic coloration. This adaptation helps them blend into plant foliage, making them difficult to detect during the early stages of infestation.

Host range. This species is a highly polyphagous pest. It attacks a wide variety of crops including cotton, citrus, legumes, various vegetable crops, and fruit trees. Its ability to thrive on diverse host plants across different botanical families makes it a significant threat in tropical and subtropical agricultural regions.

Biology and life cycle. The life cycle comprises egg, larval, pupal, and adult stages. Females lay eggs in the soil near the base of host plants. Upon hatching, larvae burrow into the soil to feed on roots, often causing invisible damage to the root system. Adults emerge to feed on leaves, often leading to rapid population growth under favorable weather conditions.

Nature of damage and economic impact. Adults consume the margins of leaves, creating a characteristic scalloped appearance, which reduces the plant's photosynthetic efficiency. Severe infestations can lead to significant defoliation, stunted growth, and loss of vigor. The larval stage, by feeding on roots, inhibits nutrient and water uptake, which may cause wilting and, in severe cases, the death of young seedlings.

Control measures. Management requires an integrated approach to mitigate impact on agricultural productivity. Recommended strategies include:

• Crop rotation to break the pest's life cycle in the soil.
• Deep tillage to disrupt larval and pupal development stages.
• Timely application of contact and systemic insecticides during the peak activity of adults.
• Use of biological control agents, such as entomopathogenic fungi, to suppress larval populations in the root zone.