A drop of 75 percent in fruit fly damage on tangerine crops has been observed in Croatia’s Neretva river delta since farmers have started using radioactively sterilised flies to fight fruit flies.
The Sterile Insect Technology consists of radioactively sterilising male fruit flies using Cobalt-60. The insects are then sprayed onto orchards in a bid to reduce the fly population and the damage they wreak on the crop. The sterilised flies can mate with other flies but no offspring will be created. Rapidly, sterilised males outnumber the local fruit flies and take the place of normal flies.
The Neretva region is expected to produce 60,000 tonnes of tangerines this year according to Reuters. Luka Popovic of the Croatian Centre for Agriculture notes that “most of them are exported but many countries have strict quarantine rules and ban imports of fruit suspected of carrying flies”.
The Croatian project is partly funded by the United Nations Agency that pays for shipment of flies costing about 2,300 euro each and containing 5 million sterilised male flies. “Between April and November, the valley of Southern Croatia are sprayed twice a week and the results have been excellent” according to Popovic.
For Jorge Hendrich, who heads a joint pest control program of the IAEA and the UN Food and Agriculture Agency notes that “the SIT method is a win-win because it enables farmers to fight a pest which can easily eliminate 30 to 100 percent of the crop and at the same time use fewer pesticides”.
The technology has been used for decades in North and South America with probing results, even eradicating the tsetse fly, which can cause “sleeping sickness” in humans and kill cattle, on the island of Zanzibar in East Africa.
However, Paul Johnston of the Greenpeace Research Laboratories at the University of Exeter states that “we should neither view SIT as risk free nor should we view it as the panacea to all food security issues”.