Genetically modified mosquitoes in Florida
Adult female yellow fever mosquito, Aedes aegypti (Linnaeus), in the process of seeking out a penetrable site on the skin surface of its host. -Photo Credit: James Gathany, Center for Disease Control Public Health Image Library
By Tami Stevenson
The University of Florida recently announced that for the first time in United States history, the experimental use of genetically modified mosquitoes is taking place in the Florida Keys. It began in the Spring of 2021, and will run through the Spring of 2022. The experiment is being led by a biotechnology company, Oxitec, from the United Kingdom.
The pilot projects involve the permitted release of adult genetically modified (GM) Aedes aegypti male mosquitoes to test their ability to reduce the population of the wild and invasive Aedes aegypti species known to spread deadly diseases to humans, by mating with wild females to produce only male offspring.
Male mosquitoes do not bite, female mosquitoes bite and feed on blood to obtain the nutrients they need to produce their eggs.
Below are some FAQ’s from their website.
Q: Are Ae.aegypti mosquitoes
native to Florida?
No. The yellow fever mosquito, Aedes aegypti (Linnaeus), has been a nuisance species in the United States for centuries. Originating in Africa, it was most likely brought to the new world on ships used for European exploration and colonization (Nelson 1986). As the common name suggests, Ae. aegypti is the primary vector of yellow fever, a disease that is prevalent in tropical South America and Africa, and often emerges in temperate regions during summer months. During the Spanish-American War, U.S. troops suffered more casualties from yellow fever transmitted by Ae. aegypti than from enemy fire (Tabachnick 1991).
Recently, this species is most responsible for transmitting dengue, chikungunya, yellow fever, and Zika viruses to humans. It is an invasive pest considered a major threat to human health in many areas of the world where the mosquito species and at least one of the viruses it transmits co-occur. Established in many areas of Florida, including the Florida Keys, it has led to dengue, chikungunya and Zika causing local outbreaks that resulted in 190, 12, and 300 human cases, respectively, over the past 15 years. Almost all of those cases have occurred in southern Florida.
Q: Has the Oxitec technology been tested elsewhere?
Yes. Oxitec has been testing their GM mosquitoes in other countries, including Brazil (Carvalho et al. 2015), the Cayman Islands (Harris et al. 2012), and Panama for the past ten years. Those experiments have all showed greater than 90% reduction in the local Ae. aegypti population, meaning the technology was effective.
Q: Can bites from the released GM Ae. aegypti mosquitoes make people sick?
No. Only adult male GM mosquitoes will be released. Male mosquitoes are not capable of biting people or animals as they lack mouthparts capable of piercing skin. Instead, they feed on nectar and other sources of sugar and may even play a role in pollination.
Q: Will Oxitec’s Friendly™ Ae. aegypti mosquito stay in nature forever?
No. This technology is designed to be self-limiting, which means that the mosquitoes that Oxitec releases into nature will gradually die off. This is expected to occur a few months after Oxitec and the Florida Keys Mosquito Control District stop releasing mosquitoes.
“Traditional control methods aren’t always effective against this highly dangerous mosquito,” said Yoosook Lee, a co-author and assistant professor of molecular ecology at UF/IFAS FMEL. “Biotechnology methods, like what Oxitec developed, can provide much needed solutions to break through insecticide resistance and hard to reach areas using conventional control methods.”
Scientists at the Florida Medical Entomology Laboratory of University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) have released a detailed consumer publication explaining what makes a genetically modified mosquito, the science of using the species as a mosquito control method, what to expect and more.