Malaria is one of the world's great scourges. Yellow fever, dengue, West Nile fever and elephantiasis are all spread by different types of mosquito. Mosquitoes can be modified genetically; versions that no longer transmit germs are available, as are sterile males that mate unproductively, driving populations down. Should GM insects be released en masse to combat the diseases they carry?
More needs to be learned about the environmental consequences of these mutant creatures. Removing one species from an environment will probably lead to new ones coming in. What diseases might these species carry? And do people want GM biting flies in their own backyard? Last year, the Oxford-based biotech company Oxitec released three million sterile GM mosquitoes in the Cayman Islands to see if the insect population would decline. Environmental campaigners expressed outrage about the lack of local consultation.
In 2002, Zambia refused to accept GM maize from the United States to relieve hunger among up to three million Zambians. And in northern Nigeria, leaders fought a political battle over the introduction of polio vaccines, insisting it was a US plot to cause infertility and spread Aids.
Surely countries that refuse GM maize to feed their starving citizens won't embrace swarms of mosquitoes unless the benefits are clear.