Annoying Summer Mosquitoes... Controlled by 'Genetically Modified' Males [Im Juhyung's Tech Talk]

World's First GM Mosquito Experiment in Florida, USA
700 Million Genetically Modified Male Mosquitoes Released to Kill Females
Pesticides Harm Beneficial Insects Like Bees and Butterflies, Risking Ecosystem Damage
Some Raise Concerns Over 'Ecosystem Disruption'

Aedes aegypti mosquito, the vector of the Zika virus. / Photo by Yonhap News

[Asia Economy Reporter Lim Ju-hyung] Mosquitoes that fly around and become a nuisance every summer. Mosquitoes are not only insects that disrupt sleep at night but also pests that carry extremely dangerous infectious diseases. Every year, disinfectant vehicles roam the streets spraying fog to prevent mosquito-borne pests.

However, there are limitations to mosquito control using insecticides. The biggest problem is that insecticides sprayed into the air leave harmful substances that damage the environment. It also frequently kills beneficial insects that help maintain the ecosystem, such as bees and butterflies, not just mosquitoes.

For this reason, recently, 'Genetic Modification' (GM) has emerged as a new alternative for pest control. The method involves creating genetically modified mosquitoes with genetic diseases and releasing them into nature to control the population over generations or even eradicate the species entirely.

The first large-scale GM mosquito release experiment is currently underway in the United States. According to local media including CNN on the 4th (local time), the Florida state government recently approved an experiment to release genetically modified mosquito eggs developed by the British biotechnology startup 'Oxitec.'

The genetically modified male mosquitoes developed by the British biotechnology company Oxitec carry a gene that kills only female mosquitoes. / Photo by Oxitec Official Website Capture

The mosquito eggs developed by Oxitec hatch into GM male mosquito larvae. These larvae grow into adult mosquitoes carrying a genetic disease, and when they mate with female mosquitoes, they pass on a gene that kills only the female offspring. As a result, the female mosquitoes that hatch next die before reaching adulthood, naturally reducing the overall female mosquito population.

By species characteristics, male mosquitoes feed on fruit juice, while only females suck blood from humans or animals. If all females die before maturing into adults, the pest mosquitoes that bother people are effectively neutralized.

Oxitec has conducted research for the past 10 years for this experiment. The U.S. Environmental Protection Agency plans to release a total of 750 million GM male mosquitoes from this year through next year and, if effective, will deploy additional releases in the future.

Mosquitoes can transmit infectious diseases harmful to humans depending on the species. Zika virus, dengue fever, and malaria are representative mosquito-borne diseases.

A military unit conducting mosquito control disinfection to prevent malaria. So far, most mosquito disinfection has been carried out by spraying insecticides into the air. / Photo by Yonhap News

Among these, malaria is a deadly disease infecting hundreds of millions annually and causing hundreds of thousands of deaths. According to the World Health Organization (WHO), approximately 230 million people worldwide were infected with malaria in 2019, and about 499,000 people, including 270,000 children, died.

Given this situation, many countries around the world have made various efforts to reduce the number of mosquitoes harmful to humans. So far, the method used is spraying insecticides containing chemicals lethal to insects into the air.

The problem is that insecticides pose a significant risk of widespread impact on the entire ecosystem. Insecticides kill not only mosquitoes but also representative beneficial insects such as bees and butterflies.

According to a 2019 paper published in the renowned scientific journal 'Biological Conservation' titled 'Worldwide Decline of Insects: A Review of Causes,' the rate of insect population decline in recent decades has been about eight times faster than that of mammals, and the main cause is likely the large-scale spraying of pesticides and insecticides. A sharp decline in bee and butterfly populations, which help plants reproduce, can collapse natural ecosystems and severely impact humanity, which depends on fruits and grains for food.

Insecticides have been found to kill beneficial insects such as bees and butterflies, as well as mosquitoes. / Photo by Yonhap News

In contrast, GM mosquitoes have the advantage of not affecting other parts of the ecosystem besides mosquitoes.

Andre Lill, chairman of the Florida Keys Mosquito Control District (FKMCD), explained the pest control method using GM mosquitoes, saying, "To fight mosquitoes without harming the unique ecosystem we live in, we need to use safe, environmentally friendly, and targeted technologies." He added, "Also, GM mosquitoes will become a new tool to effectively counter mosquitoes that have developed resistance to insecticides."

However, some express concerns that the population control method using GM mosquitoes has not yet undergone sufficient testing. They point out that it is unknown how much GM mosquitoes will reduce the female mosquito population, what changes will occur in the local ecosystem as a result, and what will happen to other insects or animals that feed on mosquitoes.

Dana Puls, an activist affiliated with the international environmental organization 'Friends of the Earth,' recently told CNN in an interview, "If GM mosquitoes are released in Florida, we do not know how local residents, the environment, and endangered species within the ecosystem will be affected." She warned, "We could all face another risk amid the ongoing COVID-19 pandemic crisis."