African spider mite

Systematic position. The African spider mite (Eutetranychus africanus) is a member of the family Tetranychidae within the order Trombidiformes. As a significant agricultural pest, it primarily affects various woody plants in tropical and subtropical climates.

Host plants. This species is known for its preference for citrus trees, including oranges, lemons, and mandarins. Beyond the citrus genus, it can also infest a wide range of fruit-bearing trees, shrubs, and certain ornamental plants, making it a persistent threat in orchards and gardens.

Biology and life cycle. The development of the African spider mite is heavily influenced by warm and dry environmental conditions. The life cycle consists of the egg, larva, two nymphal stages (protonymph and deutonymph), and the adult stage. In hot weather, generations succeed one another rapidly, allowing for massive population explosions within a very short timeframe.

Nature of damage and harmfulness. The mites feed by piercing plant cells and extracting chlorophyll-rich sap, primarily from the upper leaf surface. This feeding activity leads to the characteristic stippling, chlorosis, and bronzing of leaves. In severe infestations, the tree experiences premature defoliation, stunted growth, and reduced fruit quality, directly impacting agricultural output.

Protection measures. Effective management requires an integrated approach to suppress population growth and prevent economic damage:

• Application of specialized acaricides when mite density reaches the economic threshold.
• Maintenance of proper canopy humidity to create unfavorable conditions for mite development.
• Introduction of natural predators, such as phytoseiid mites, to biological control the pest.
• Routine monitoring of leaves to detect early infestations before they spread across the orchard.