Mechanisms of resistance to the cassava green mite mononychellus tanajoa (bondar) on pubescent and non-pubescent cassava varieties

Cassava varieties resistant to the cassava green mite, Mononychellus tanajoa (Bondar) (Acari:Tetranychidae) have been reported in many parts of Africa where the pest has been introduced. However, the resistance mechanisms have not been identified. Laboratory studies on biology and feeding behaviour of cassava green mite were carried out at the International Institute of Tropical Agriculture (IITA), in order to determine whether this resistance is mainly due to pubescence. Cassava pubescence was found to have no antibiotic effect; both pubescent and non-pubescent varieties were preferred by the mite for ovipositton, food and shelter. In addition, pubescence does not afford a mechanical barrier to cassava against green mite infestation. ©1998ICIPE.