Coffee root mealybug

Systematic position. The coffee root mealybug (Rhizoecus coffeae) is classified within the order Hemiptera and the family Pseudococcidae. Unlike foliage-feeding mealybugs, this species is entirely hypogeous, meaning it spends its entire life cycle underground, feeding on the root systems of its hosts.

Affected crops. While initially identified as a pest of coffee plants, this insect is a widespread polyphage. It frequently infests ornamental potted plants, including cacti, succulents, palms, and various tropical foliage plants grown in greenhouses, nurseries, and indoor environments.

Biology and life cycle. These insects are characterized by their small size and the production of a white, waxy secretion that covers their bodies and surrounds the roots. They reproduce sexually, and populations can grow rapidly in stable soil conditions where moisture levels are moderate, making them a persistent issue for pot-bound plants.

Nature of damage and harmfulness. The pests pierce the root tissues with their mouthparts to extract sap. This leads to reduced nutrient and water uptake, resulting in symptoms such as yellowing leaves, stunted shoot growth, and general wilting. In severe infestations, the root system may become so damaged that the plant collapses, often exacerbated by secondary root rots.

Protection measures. Effective control requires targeted soil-applied treatments. The following steps are recommended:

• Applying systemic insecticides as a soil drench to reach subterranean populations.
• Repotting the plant using fresh, sterilized substrate while removing heavily infested roots.
• Thorough cleaning and disinfection of pots and growing benches to prevent re-infestation.
• Monitoring the roots of new plants before introducing them into the collection.