The green cassava mite, Mononychellus tanajoa (Bondar) and the red spider mite, Tetranychus urticae Koch infest all varieties of cassava in Sierra Leone. Both tetranychid species are widely distributed in the country and are causing severe damage to the crop mainly in the major cassava producing areas in the north-western regions. M. tanajoa caused chlorosis and 91° loss in photosynthetic area of the attacked leaves and defoliation of the plant either by acting alone or in concert with T. urticae. Late planted crop was particularly vulnerable to the infestation. M. tanajoa and T. urticae appeared to avoid severe interspecific competition on the plant by habitat stratification.
