A parasitic wasp has been released in mango-producing regions in the country to control fruit flies which cause great damage to mango fruit.

The technique is the brainchild of the African Insect Science for Food and Health (ICIPE), Kenya Agricultural Research Institute (KARI) and the Ministry of Agriculture.

This new biological weapon against fruit flies, uses "beneficial" insects or parasites called parasitoids, for effective control of the fruit fly.

Mango producers are being educated on the new innovation through the Organic Farmer Magazine, a publication of ICIPE that is distributed free of charge to farmers especially those practicing organic farming.

Dr. Sunday Ekesi, a senior scientist at ICIPE, says the parasitic wasp is highly efficient in controlling the fruit fly menace, and can be used alongside other measures that are applied against the pest.

He says in collaboration with KEPHIS, (KARI) and the ministry of Agriculture, the wasps have been released across Kenya.

''The parasitoid is self perpetuating, works free and needs no input from the grower'', notes Dr. Ekesi. If the technique succeeds, farmers will greatly improve the mango yields, adds the scientist.

For the parasitoid to work effectively, growers must minimize cover spray of pesticides in their orchards to avoid killing them.

The scientist explains that the weaver ant attacks the eggs of the fruit fly, and develops through the larval stages of the fruit fly before killingh the host.

To retain the weaver ant during dry season, he says farmers can provide dried fish for the ants to feed on for their energy and nutritional value.

He says there are four dangerous types of fruit flies which destroy mangoes and other fruit trees. The weaver ant must be induced to feed on the other pests on trees grown along with mango.

Dr. Ekesi says that although there are several methods of controlling the fruit fly, ICIPE promotes a combination of methods through the use of Integrated Pest Management (IPM) technique.

Among the techniques applied is baiting, orchard sanitation, mechanical fruit protection and inoculation with fungal pathogen.

Research at ICIPE shows that a protein bait from brewers yeast obtained as industrial by-products, can be applied in low volumes to spray one square meter of mango canopy.

Mango farmers in Kitui Central District are counting the losses as a result of mango fly invasion , a pest they claim has recently been notified.

Area District Agricultural Officer Munene Mutindwa say that farmers affected are those who grow for sale grafted mangoes.

Benard Singi a large scale mango farmer along the banks of Thua River in Zombe division of Mutito District said that due to the disease his yield has decreased from seven tons to five tons in the last two months.

''I have been using the normal pesticide for spraying the plants but the disease has persisted unlike in the past when the spraying method reduced pest invasion,'' Singi told Xinhua.

Retired Major Mathias Maingi a mango farmer in Kwa-Ukungu Village in Kitui Central district said he was forced to seek assistance from KARI researchers in Machakos after a pest unknown to extension officers in Kitui invaded his farm.

Despite the advice given, the devastation is still great though the pest has been identified as the fruit fly.

He however says the invasion has greatly reduced the production but hopes the new innovation being enhanced will repel the pest.

Josphine Musyoki of the Kitui Kenya Forestry Researcher Institute (KEFRI) also confirmed that the pest has been identified in mango farms in Mbitini location in South Kitui.

''The most affected mango species is that of apple, kent though the traditional mango from the district is affected though the farmers have not noticed since it is not used commercially'', says Ms Musyoki.

Yield loss on mangoes in Kenya, Tanzania and Uganda due to fruit flies ranges between 30 percent and 70 percent.

The rise is attributed to an invasion of the fruit fly. Lowlands are the most afflicted, with damage rising to as high as 80 percent.

As a consequence of the devastation, exports of mangoes to lucrative markets in South Africa, Europe, the Middle East and Japan has reduced significantly.