BIOLOGICAL CONTROL OF THE MANGO MEALYBUG (RASTROCOCCUS INVADENS) IN TOGO
In 1986 a classical biological control programme was set up against a pest affecting mango, citrus and around 40 other plant species, accidentally introduced to West Africa and newly identified as Rastrococcus invadens Williams. Institutions involved in the programme included IIBC, charged under an FAO contract with basic studies and quarantine, as well as the Togolese plant protection service (SPV) reinforced by the German technical assistance agency GTZ. The pest species was re-isolated in South India along with one of its parasitoids, Gyranusoidea tebygi Noyes, selected later as a promising biocontrol agent. After its introduction to Togo in October 1987, it was mass reared in a rather simple and cost effective unit, that allowed for the first release after only one month. G. tebygi established readily and spread over a range of more than 100 km within 10 months. By February 1989 it had invaded all the mealybug infested areas of Togo and parts of the neighbouring countries. Monitoring of pest and parasitoid populations over 4 years proved the overall control success to be very satisfactory. A range of previously affected host plants have been freed from the pest, although on mango the mealybug persists to a small extent, giving rise to occasional population increases. In economical terms, biological control has proven to be extremely effective and the only feasible approach to efficiently tackling the mealybug scourge within the West African subsistence farming system.
Agounké, D. and Fischer, H.U. (1993). BIOLOGICAL CONTROL OF THE MANGO MEALYBUG (RASTROCOCCUS INVADENS) IN TOGO. Acta Hortic. 341, 441-451
parasitoid, Encyrtidae, hyperparasitism, monitoring, programme evaluation