Green weevil

Systematic position: Myllocerus viridanus belongs to the order Coleoptera and the family Curculionidae. It is recognized as a significant pest within the Entiminae subfamily, commonly known as broad-nosed weevils, which are notorious for their diverse dietary habits.

Host plants: This pest is a polyphagous insect, meaning it attacks a wide variety of plants. Primary hosts include tea plants, cotton, citrus trees, legumes, and various ornamental species. Its ability to shift between different host types allows it to persist in diverse agricultural landscapes.

Biology and lifecycle: The insect undergoes a complete metamorphosis. Adults are typically active during the growing season. Females deposit eggs in the soil near the base of host plants. The larval stage is subterranean, where larvae feed on fine roots, while adult beetles feed on foliage, creating distinct nutritional cycles at different stages of life.

Damage and economic impact: Adults cause defoliation by eating leaf margins, leaving a characteristic notched appearance. This feeding behavior reduces photosynthesis and weakens the plant. More critically, larval root feeding disrupts nutrient and water uptake, which can lead to stunted growth, reduced yields, and even the death of young seedlings in heavily infested fields.

Control measures: Management strategies focus on reducing populations during critical growth stages. Recommendations include:

• Application of systemic insecticides to manage adult populations during peak emergence.
• Soil treatments to control larval populations before they cause significant root damage.
• Cultural practices like deep soil cultivation to disrupt the pupation sites.
• Monitoring using yellow sticky cards or light traps to determine the timing for chemical applications.