The United States Environmental Protection Agency (EPA) has authorized the release of more than 2 billion genetically modified mosquitoes into the states of California and of Floridawith the aim of combating diseases such as dengue fever and the Zika virus.
The pilot project is the product of British biotech company Oxitec, which specializes in biological pest control. The project is an extension of a successful pilot carried out in theKeys archipelago in 2021.
Oxitec plans to release 2.4 billion non-biting Aedes aegypti mosquitoesgenetically modified to produce only viable male offspring. When the males reproduce, they will pass the self-limiting gene to the next generation. In this way, the population of Aedes aegypti will become overloaded with males, causing the population to decline.
A job inside
The Aedes aegypti mosquito originated in Africa but has since spread to tropical and subtropical regions around the world. It was first detected in California in 2013, before embarking on a range expansion to United States which has seen the species spread to over 25 states.
Aedes aegypti is known to spread a number of deadly diseases including dengue fever, yellow fever, Zika virus and Chikungunya. The species feeds on a range of birds and mammals, with a preference for humans.
However, as with all mosquitoes, only females feed on blood, using it to mature their eggs. Males are harmless and do not spread disease, preferring to feed on fruit instead.
“Given the growing health threat posed by this mosquito in the United States, we are working to make this technology available and accessible,” said Gray Frandsen, CEO of Oxitec. “These pilot programs, in which we can demonstrate the effectiveness of the technology in different climatic contextswill play an important role in this regard.”
Genetically modifying male mosquitoes to prevent them from producing female offspring is an effective way to reduce mosquito populations and is a more environmentally friendly solution than using pesticides. Pyrethroids – a group of pesticides commonly used to control mosquitoes – are toxic to insects such as bees and dragonflies, as well as aquatic life.
Opponents question security
While the EPA concluded that the project is harmless to humans and the environment, opponents raise concerns about unintended consequencesparticularly regarding the potential interaction of mosquitoes with the antibiotic tetracycline.
This antibiotic can be found in sewage from farms and is known to reverse genetic changes in mosquitoes, allowing the production of female offspring.
The EPA has therefore stipulated that mosquitoes cannot be released within 500 meters of sewage treatment facilities, livestock areas or fruit farms.. For the project to proceed, it is now up to state regulators in Florida and California to provide permits to Oxitec.