Angolan whitefly

Systematic position: The Angolan whitefly, Rugaleyrodes angolensis, belongs to the order Hemiptera and the family Aleyrodidae. As a specialized agricultural pest, it primarily affects crops in sub-Saharan African regions, posing a significant challenge to local food security and plantation agriculture management.

Host crops: This insect has a diverse host range, focusing on plants with high agricultural value. It is particularly noted for causing damage to cassava fields, citrus orchards, and various leguminous and vegetable crops, where it thrives by exploiting the phloem sap of these plants during their active growth stages.

Biology and life cycle: The lifecycle of Rugaleyrodes angolensis consists of egg, four nymphal instars, and the adult stage. The adult insects are winged and capable of flight, which facilitates their spread across fields. The rapid development of nymphs on the undersides of leaves, favored by warm and humid environments, allows for overlapping generations and continuous population pressure on crops throughout the year.

Nature of damage: The damage is twofold: direct and indirect. By piercing the plant tissues and feeding on phloem sap, the whiteflies deprive the plant of nutrients, leading to yellowing, leaf drop, and stunted growth. Furthermore, the excretion of honeydew promotes the growth of sooty mold, which coats leaves and fruits, impairing photosynthesis and rendering the produce unmarketable.

Protection measures: Integrated Pest Management (IPM) is essential for controlling this pest. Recommended strategies include:

• deploying yellow sticky traps to detect and suppress adult populations;
• applying selective systemic insecticides when infestation thresholds are exceeded;
• implementing sound cultural practices, including the removal of infested weeds and crop debris;
• encouraging the presence of natural predators and parasitoids to maintain ecological balance in the field.