Researchers say the warming climate has pushed tropical diseases like dengue and chikungunya further north. These are both viral infections carried by mosquito species like Aedes aegypti, which transmits the virus to humans when biting. Both viruses cause extreme muscle and joint pain, fever, nausea, and plenty of other unpleasant symptoms. Dengue can occasionally progress to life threatening hemorrhagic fever as well. Chikungunya is also known to cause chronic disease that results in joint and muscle pain for years after the initial infection.

Basically, these are diseases you do not want to get, but they’re starting to pop up in Florida. There are no approved vaccines that can prevent infection with either virus, so mosquito control is seen as the only viable option. Local governments have taken to spraying six different pesticides in an attempt to keep the mosquito populations under control, but A. aegypti has already evolved resistance to four of the six agents. It’s much harder for mosquito populations to adapt if you’re targeting them with DNA, though.

Oxitec’s plan involves the production of mosquitoes with modified genetic code containing DNA from the herpes simplex virus, E. coli, coral, and cabbage plants. This is accomplished by injecting eggs with modified DNA as seen below. Millions of these organisms would be bred, then the females would be removed from the population before release. Females are the ones that bite and drink blood, so only non-biting male mosquitoes should be released in Florida, assuming the FDA approves.

These GMO insects will go about their business doing regular mosquito things until they mate with wild female mosquitoes. The modified DNA in the experimental insects will cause all the offspring from this union to die, thus reducing the population of mosquitoes by crowding out wild-type males that can produce viable offspring. This also means the GMO mosquitoes are self-limiting as they cannot reproduce.

Oxitec has conducted initial tests in Brazil and the Cayman Islands, both of which were successful enough that the countries are planning larger deployments of GMO mosquitoes. If approved by the FDA, Oxitec could release the bugs this spring in southern Florida. However, there is local opposition to the plan, based at least partially on a lack of understanding. A Change.org petition (with nearly 150,000 signatures) makes a number of misrepresentations and omissions in its portrayal of the plan.

That’s not to say there are no concerns. For example, it’s possible some female mosquitoes could be accidentally released and bite humans. Oxitec says even if that happens, there’s no evidence that would result in the transfer of modified DNA, or that such a thing would harm anyone. It’s up to the FDA now to decide if the project goes forward, but Oxitec does have a lot of data to show their method is effective and safe from laboratory testing as well as the tests in Brazil and the Cayman Islands.