Effect of Ant on biological control of a neotropical herbivorous mite pest Mononychellus tanajoa (Acari: Tetranychidae) a mite pest of cassava in Africa.

The effect of ants on phytoseiid mites has been rarely studied. On cassava plants in Africa, the predatory mite, Typhlodromalus aripo, introduced from Brazil to Africa for the biological control of the cassava green mite, Mononychellus tanajoa, is frequently found sharing cassava plants and their extrafoliar exudates with several species of ants. Indeed the effect of Ant on biological control of Mononychellus tanajoa has been studied by a series of surveys in 18 farmer-managed cassava fields in southern-Benin where we determined densities of ants, T. aripo and M. tanajoa on 30 cassava plants in each field. Survey results showed that several ant species in the genus Camponotus were most common on cassava plants in southern-Benin. Ant abundance was highest in cassava fields bordered by forest or dense vegetation and when fields were ‘weedy’, while T. aripo was least abundant in weedy cassava fields compared with relatively well-weeded fields. Overall, increasing ant abundance in cassava fields was associated with lower T. aripo abundance and higher M. tanajoa densities.