A traditional pest control method used in China could also help African farmers keep about 60 percent more of their high value crops, according to a recently released research by the Africa Rice Center in Benin.
Mangoes and other high value crops could be rescued from fruit flies, the research shows.
Dr Paul Van Mele and his colleagues reported in the US-based Journal of Economic Entomology that weaver ants could be the key. They said the ants could be used for mango pest control in Africa because the ants, once placed on mango trees, patrol the trees throughout the year and prey on fruit flies and their larvae.
Fruit flies are responsible for destroying about 40 percent of Africa's annual mango production of about 2 million metric tons. Mangoes are one of Africa's most important sources of Vitamin A and a potential export.
The African researchers are the first to show that Oecophylla longinoda, an African weaver ant, protects mangoes against all of the fruit flies available in the fruit fly complex - at least five different species in West Africa, including the invasive species from Asia, Bactrocera invadens.
"The latter was discovered on the African continent only since 2003 in East Africa and 2004 in West Africa," Dr Van Mele says.
The studies also showed that the application of weaver ants could completely reduce the need for pesticides - a major expense for African farmers - and significantly improve fruit quality.
Centuries ago, weaver ants were documented as a powerful weapon guarding citrus fruits against insect damage in South China. While the weaver ants exist in abundance in Africa, their use is still at the experimental stage in many countries.
Dr Van Mele first discovered the weaver ant's power around 1970 in Vietnam, where predatory ants are also under research and are considered a viable method to help sustain agricultural systems.
More research will be needed to test the effectiveness of weaver ants in controlling major pests in multiple contexts, crops and agro-ecosystems across Africa, and farmer awareness programs should be developed to assist the spread of the technology, he says.
"Share of information is also important between countries," Dr Van Mele adds, referring particularly to African countries and China, as the latter has rich experience and time-honored history in agricultural science.
(China Daily July 30, 2007)
