EPA just approved the release of killer mosquitoes in 20 US States

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I don’t have the power to read minds, but I am sure I can guess one thought you had: “why nature created mosquitoes? What’s the point?” I can’t answer that question as like you, I wish them gone, but today I want to report about a news regarding mosquitoes. 

The US Environmental Protection Agency (EPA) has just approved the release in 20 US states of killer mosquitoes, engineered in a lab to eliminate disease-carrying mosquitoes.  

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Why? 

Well it’s not that our institutions decided to finally join us in our crusade against nature’s most annoying creation. But their reasons are noble nonetheless. We have all heard that mosquitoes can spread disease. For the sake of spreading good information I want to clarify that mosquitoes themselves are harmless for us, but they can act as a carrier for blood pathogens. In fact, mosquito that bites an infected human or animal can pick up a virus along with the blood meal. The mosquito and virus do not harm one another but the virus reproduces inside the mosquito. Later, the mosquito can pass the viruses to other humans when biting them. 

Here there is a list of pathogens/diseases that can be transmitted by mosquitoes’ bites:

• Zika virus 
• West Nile Virus 
• Malaria 
• Dengue Fever 
• Chikungunya 
• Dog Heartworm 

So what exactly are these killer mosquitoes? 

The theory is that mosquitoes will be infected with a bacterium called Wolbachia pipientis and then males will be sorted from females. Then the laboratory males, which don’t bite, will be released at treatment sites. When these males mate with wild females, which do not carry the same strain of Wolbachia, the resulting fertilized eggs don’t hatch because the paternal chromosomes do not form properly. 

Over time, with the constant release of infected males, the population of disease-carrying mosquitoes should dwindle without affecting other insects as there won’t be use of any chemical involved.  

What criteria was used to pick the US states in which the killer mosquitoes will be released? 

The EPA restricted the release of the killer mosquitoes to areas with a similar climate (temperature and precipitation) to areas in which the field trials were conducted. For this reason, these mosquitoes will be released in states like Kentucky, New York, California and Washington DC. The southeastern states were excluded despite having dense populations of mosquitoes and a long mosquito season, because of climate differences compared to the field trials. 

This task will be assigned to a company called MosquitoMate (their killer mosquitoes are called ZAP males). This company has also plans to sell these mosquitoes locally. They envisage working with homeowners, golf courses, hotels etc. The issue with suppressing mosquito populations of entire cities is that it would require a weekly production of millions mosquitoes. Considering that the company’s technicians now separate them both by hand and mechanically, it may be challenging to generate enough killer mosquitoes to cover large areas.  

We are not the first 

There are other countries that started tackling this issue and have already experience with release on the field of killer mosquitoes. This practice has been used extensively in Brazil since 2015 due to the Zika virus epidemic.

China is another example, in fact Researchers from Sun Yat-sen University in Guangzhou are currently releasing 5 million killer mosquitoes each week in Guangzhou. They managed to increase the production of these mosquitoes by automating the sorting between male and females. They employ mechanical sorters to separate males from females, on the basis of size differences at the pupal stage, at more than 99% efficiency. The remaining mosquitoes are exposed to X-ray at a dose that can sterilize the females but that are too low to cause problems to the males.  

I am curious to see if this experiment will work, unfortunately there are thousands of people affected by these diseases every year. Prevention may be better than scrambling to find cures.      

Sources:

https://www.nature.com/news/us-government-approves-killer-mosquitoes-to-fight-disease-1.22959

http://npic.orst.edu/pest/mosquito/diseases.html