Establishment and spread ofGyranusoidea tebyginoyes andAnagyrus mangicolanoyes (hymenoptera: encyrtidae), two biological control agents released against the mango mealybugRastrococcus invadenswilliams (homoptera: pseudococcidae) in Africa

Socio-economic impact of biological control of mango mealybug in Benin

“…This can be summarized in the benefit-cost ratio of 145:1, which was based on initial costs in Togo and costs and benefits in Benin. The two parasitoids were later distributed over all of West Africa and some countries in Central Africa at little additional costs (Neuenschwander et al, 1994, and unpublished results by the same authors). Therefore, the benefit-cost ratio for the biological control of mango mealybug for the whole region is likely to be substantially higher.…”

“…An increase beyond the original mango production is attributed to the fact that during the last 10 years many new mango orchards had been established and were coming into production. To what extent the second parasitoid, A. mangicola, which was established later (Neuenschwander et al, 1994;Neuenschwander, 1996), contributed to the decline of the mealybug populations and increased mango production remains unknown.…”

“…However, reports of persistent "hot spots" of infestations despite the presence of G. tebygi (Bokonon-Ganta and Neuenschwander, 1995) led to the importation, rearing and release of a second parasitoid wasp, Anagyrus mangicola Noyes (Hymenoptera: Encyrtidae). In Benin, it was released in 15 batches from 1991 to 1993 (Neuenschwander et al, 1994).The successful establishment of this second wasp brought a further, local reduction of pest populations (Bokonon-Ganta et al, 1996). A recent study found that the parasitoids are also well established in Nigeria, and that the populations of the mango mealybug have been greatly reduced (Pitan et al, 2000).…”

“…In Benin, 10 batches of the first parasitoid G. tebygi were released at different sites from 1988 to 1993 (Neuenschwander et al, 1994).…”

“…The parasitic wasp, Gyranusoidea tebygi Noyes (Hymenoptera: Encyrtidae) was imported from India (Narasimham and Chacko, 1988) and studied in quarantine (Willink and Moore, 1988). The wasp was reared, released and established in different places in Africa (Agricola et al, 1989;Neuenschwander et al, 1994).…”