Why 10 million tiger mosquitoes are being deliberately released in Nouvelle-Aquitaine
The potentially dangerous insects are now in every region of the country
One female tiger mosquito can lay up to 300 eggs
Soumyabrata Roy/Shutterstock
Tiger mosquitoes are now a scourge in France with the potentially dangerous insects being spotted in every region across the country.
One area is trying to stifle the problem with an innovative solution that involves releasing up to ten million more of the insects.
These mosquitoes will all have one thing in common - they are all sterile and cannot reproduce.
Authorities in Brive-La-Gaillarde (Corrèze) are the first in the country to take part in such a scheme, at a cost of €52,000.
The first set of 40,000 sterile males were released this week, with more being deliberately let loose every few days until the end of the season in autumn.
“It's going to do some good, because last summer was awful,” said one resident to media outlet TF1.
“It might be a better method than spraying a bunch of chemicals,” said another.
Alongside being a nuisance with their biting, tiger mosquitoes can be a vector for several diseases including dengue, Zika, and chikungunya.
How does the technique work?
The aim of the plan is simple – by overriding the area with millions of sterilised male mosquitoes, females are likely to attempt to partner with one of these during their brief mating period (they only try to mate once in their lives).
The eggs the females lay will then be empty, failing to produce larvae, and thus quickly reducing the species’ population in the area.
The short lifespan of tiger mosquitoes – 21 days – means they will be unlikely to find a non-sterile mating partner after the influx of sterile males.
Mosquitoes mostly stay in the same location throughout their life, not flying more than a kilometre from where they hatch, meaning the extremely localised plan can drastically reduce numbers in a specific area.
Despite the release of 10 million mosquitoes sounding particularly threatening, there will be no increase in disturbance to humans as male mosquitoes do not bite humans. Only females bite as they seek blood for egg production.
Such ‘sterilisation’ techniques are used worldwide, notably to combat invasive species such as screwworm in North and Central America.
Does not replace current methods
However, the local council is clear that the scheme is designed to be used alongside current anti-mosquito methods and will not replace them.
These include action both at a municipal level – such as monitoring the area’s rainwater network – and at a personal resident level.
Residents should still ensure they are removing stagnant water from their property to reduce possible mosquito breeding grounds.
Quick removal of possible breeding grounds is vital due to the exponential spread of the mosquitoes during mating season.
One female can lay up to 300 eggs, with around half of these being females who can also lay up to 300 eggs just a few days after hatching.
Within a few weeks, up to 45,000 tiger mosquitoes can be present.
