It is a pleasure for me to participate with all of you today in the inauguration ceremony for another insectary of the tsetse mass-rearing facility in Tanga, the first of this size in the African continent. One may wonder why we need to make such a big effort to increase the population of tsetse flies as we all know that they are harmful to cattle and to human beings. In fact, only male tsetse flies are the produce of these insectaries. They are then rendered sterile, that is, unable to reproduce, using gamma radiation from Cobalt 60 or Caesium 137 sources, and released in areas infested by the wild male and female tsetse flies. The population of the pest will decrease after a while of releases, until it is extinguished if more sterile insects are released in the infested areas. This technique to suppress harmful flies is what we call the Sterile Insect Technique or, in short, SIT. In principle, it is an effective birth control of insect pests.
The technique depends on nuclear energy in two respects. Firstly, each sterile male released has been treated by gamma radiation. Secondly, the blood required in the rearing factories for feeding tsetse flies must be decontaminated by the same gamma radiation, but at a different dose. That is the reason why the International Atomic Energy Agency, through the application of ionizing radiation, is involved, together with FAO, in projects in the agricultural sector for pest control and eradication.
Over the years, tsetse and trypanosomosis management has depended on two major components: trypanocidal drugs for treating livestock, and conventional tsetse control using insecticide techniques. However, all available conventional methods have their specific deficiencies. Trypanocidal drugs are very expensive and increasing resistance of the blood parasite to the drugs is a major concern. The aerial spraying of insecticides used in the early days was very harmful to the environment and was replaced by a combination of insecticide impregnated targets placed in the fields and pour-on insecticide on livestock. These tsetse control methods are largely based on rural community participation. However, due to the lack of adequate logistics, sufficient financial means, strong support from government organizations, and continuous efforts by the community, the problem quickly reverts to its old dimensions even if the fly population is reduced for a certain time.
We contend that in several areas in Africa, tsetse eradication, through the additional use of SIT, is technically feasible, economically justifiable and sustainable. In principle, conventional methods are most efficient at very high insect pest population densities. SIT is most effective when tsetse populations are low because the success of this technique is determined by the ratio of released sterile to native fertile males. If conventional community-based tsetse control methods are used first to sufficiently reduce the fly population in a region, and then SIT is applied, we can guarantee high efficiency throughout the entire suppression/eradication campaign.
Over the past decade, the IAEA and FAO have substantially contributed to successful pest insect control or eradication campaigns in many developed and developing countries. Everybody here will still recall the eradication of the New World Screwworm fly from Northern Africa. I would also like to bring to your attention that in December last year, the Chilean Government declared the country free from Mediterranean Fruitfly (also called Medfly); the result of another IAEA/FAO supported SIT campaign.
Government agencies and the private sector are appreciating more and more the environmental and economic advantages of using SIT for fruitfly control or eradication. In several areas of the world, grower associations are becoming increasingly interested in the Sterile Insect Technique as it is less expensive than other control methods and it enables the production of high quality fruit which is free of pesticide residues.
In response to the increased demand for sterile fruit flies in SIT campaigns, there are already 13 fruitfly factories producing sterile males all over the world. A factory in Guatemala has been selling 200 million sterile flies per week for releases in the Los Angeles basin in California, and has used some of the profit to erect another and much larger medfly production factory. As a result of the use of SIT packages (sterile flies and aerial releases), no wild Medflies were detected throughout the release area in the Los Angeles basin during the past two years.
According to a recently published Environmental Monitoring Handbook for Tsetse Control Operations, "The only tsetse control method known which has no side effects on non-target organisms, is the SIT". The environmental advantages of the SIT are accepted worldwide. In fact, in the Los Angeles basin Medfly SIT campaign, environmentalists demonstrated in favour of expanding SIT releases to other areas that were still treated with insecticides. This has been one of the rare occasions where environmentalists have demonstrated in favour of a nuclear technique!!
The IAEA is a partner in the concerted international effort to alleviate one of the major problems of sub-Saharan Africa, the tsetse transmitted trypanosomosis. Tsetse quite rightly has been called "Africa's bane". Tsetse and trypanosomosis are the factors that separate livestock keeping from farming in many areas with high agricultural potential in sub-Saharan Africa. It seriously affects existing agricultural systems and, in spite of the enormous demographic pressure to utilize arable land, trypanosomosis prevents the establishment of sustainable mixed smallholder farming systems. The elimination of this pest would enable families to rear healthy cattle for producing meat, milk, manure and, particularly, for draught power, with which a family could grow food crops on areas at least 20 times larger than the land farmed without cattle.
In order to efficiently use the Sterile Insect Technique against tsetse, we want to make available all the expertise gained, and methods developed during the past decades, from Screwworm and Medfly SIT operations. The farmers in African countries should also benefit from the success of SIT packages. Here at the Tsetse and Trypanosomosis Research Institute in Tanga (TTRI), using the refurbished insectaries and new equipment provided by the IAEA through a Zanzibar Government IFAD loan and other donors, the well trained and dedicated team of technicians and scientists has managed to increase the tsetse colony here to a new world record level of more than 600,000 female flies. I have been informed by our experts that because the southern part of Unguja Island is being flooded with more than 50,000 sterile males per week reared in Tanga, the wild target tsetse population barely has a chance to survive.
The progress made at Tanga and on Unguja has received considerable attention by other African countries. IAEA has recently been approached by three Member States inquiring about the possible use of the SIT package in their national efforts of tsetse and trypanosomosis control. For the future implementation of these projects in the sub-region, TTRI may very well be one of the sterile male production facilities to supply the necessary sterile flies.
However, in order to be able to contribute to larger projects on the African continent, many more flies need to be produced, and at a lower cost. This can be achieved through efforts undertaken in the field of tsetse rearing automation. The aim is to standardize quality sensitive aspects of tsetse mass production and to establish modular tsetse factories comparable to existing Medfly and Screwworm factories.
I would like to congratulate you for the outstanding progress achieved so far with the Tsetse Eradication Project on Zanzibar. Tanzanians are becoming leaders in Africa in SIT for the eradication of tsetse flies and trypanosomosis. The IAEA is proud of having contributed to this centre of excellence for tsetse production, particularly as the TTRI is now in a position to serve also as the major training site for tsetse SIT in Africa. The IAEA counts on the scientific staff of the Institute to assist the FAO/IAEA programme as experts on tsetse rearing in other African countries. I encourage the Government to ensure that this facility is maintained in good operational condition and that the staff are able to assist other possible projects in Mainland Tanzania and in other countries.
I want to encourage you to keep working hard to further improve this nuclear technique and to make good use of it for the development of sustainable agricultural systems for the people in Tanzania and for other tsetse affected countries.
The substantial improvements of agricultural systems in Tanzania is within your reach and I wish you good luck for all the future tasks and challenges.