In a controversial move, biotech firm Oxitec has released hundreds of millions of genetically modified mosquitoes into the wild.
Mosquitoes are a pain, both figuratively and literally. While these pesky creatures can cause an intense itch and frustration, they can also spread some deadly diseases. One mosquito species, in particular, the Aedes aegypti are responsible for causing a wide range of diseases: dengue, chikungunya, yellow fever, and Zika among others. So, why is the US releasing 750 million of these genetically modified mosquitoes into the wild?
Unfortunately, we’re seeing our toolbox shrinking due to resistance. That’s one of the reasons why we’re really looking at these new innovative tools and new ways to control this mosquito.
Andrea Leal, executive director of FKMCD
The incidence of mosquito-borne diseases is gradually increasing day by day. Moreover, current methods of spraying insecticides have been unsuccessful at controlling the spread of disease. And the widespread use of these pesticides has also resulted in the mosquitoes become resistant to such measures. Therefore, researchers at Oxitec have come up with an effective alternate: genetically engineered mosquitoes. Using biotechnology, researchers have genetically engineered male mosquitoes to carry a lethal gene. When these male mosquitoes mate with the wild female population, the lethal gene is passed to the male and female offspring. Thus, resulting in the death of female offspring before maturation and a decrease in their number. On the other hand, male offspring that don’t bite or spread disease are not affected. Instead, they become carriers of the lethal gene, passing it to future generations.
Previously, Oxitec had tested the release of modified Aedes aegypti in Brazil, Malaysia, Panama, and the Cayman Islands. The mosquito population went down by 90% in these regions.
12,000 Mosquitoes Expected to Hatch
Researchers believe this particular method will help control the spread of deadly mosquito-borne diseases. Particularly, in Florida Keys where the incidence of these diseases has shown a significant increase. The Florida Keys Mosquito Control District (FKMCD) board has approved Oxitec’s plan to release these genetically modified mosquitoes within the region.
In late April, the biotech firm placed boxes of genetically modified mosquito eggs across six locations in Florida Keys. About 12,000 male mosquitoes are now expected to emerge from these boxes. As part of the study, researchers aim to capture these mosquitoes and asses for various factors. They will measure how far these genetically modified mosquitoes travel from the boxes, their length of survival, and whether they are able to reduce the female population. If this experimental study is successful, the researchers plan to release further 20 million mosquitoes into the region in the coming weeks.
Our primary mission is to protect residents in the Florida Keys from all mosquitoes including the disease-transmitting Aedes aegypti. The Florida Keys Mosquito Control District remains committed to seeking out, environmentally friendly and targeted tools to protect our residents and to preserve our wildlife.
Andrea Leal, executive director of FKMCD
A few groups have raised concerns about the impact such measures can have on the ecosystem. However, the Environmental Protection Agency (EPA), after much testing, has given the technology its approval. Researchers hope to have more evidence for the safety of their experiment as data becomes available.
Reference:
Evans, B.R., Kotsakiozi, P., Costa-da-Silva, A.L. et al. Transgenic Aedes aegypti Mosquitoes Transfer Genes into a Natural Population. Sci Rep 9, 13047 (2019). https://doi.org/10.1038/s41598-019-49660-6
