Why you may still have mosquitoes in your French home… in autumn and winter

The end of the summer period in France brings changes to natural life in France, including insects.

Some will think of the increasing numbers of spiders they are likely to spot at home, however many may also breathe a sigh of relief that irksome insects such as mosquitoes are coming to the end of their season.

Considering the record number of native cases of the mosquito-borne disease Chikungunya recorded in France this year, this would be welcome news. 

Mosquitoes surviving into winter

It unfortunately is not quite the case, however, as mosquitoes are surviving longer into the traditional autumn and winter months. 

One reason for this is that warmer temperatures lasting later into the year prolong their effective breeding season, meaning they are now more frequently spotted in October and November. 

At the same time as temperatures stay warm, the autumn rains provide more areas for them to lay eggs and thrive for a couple of extra lifecycles.

Whereas mosquitoes that are outside will die off sooner, those inside homes can survive longer, benefitting from the warmer inside temperatures. 

In rare cases, such as homes with a flooded basement – mosquitoes may even be able to lay eggs, further prolonging the season. 

It is not unheard of for someone to receive a mosquito bite in December, particularly in southern areas of France. 

Tiger mosquitoes benefit

Common (Culex) mosquitoes native to France are beneficiaries of this longer period, adapting to the change in climate to prolong their effective season. 

They risk infecting humans with West Nile Virus.

However it has also been advantageous for tiger mosquitoes, a species which transmits diseases such as Dengue fever and Zika alongside Chikungunya. 

These diseases are spread by mosquitoes originally biting an infected individual and contracting the virus, and then biting other, uninfected people.

Native to tropical climates, the animals have been known to survive well into the autumn in the south of France, particularly along motorway service stations. 

They have now been spotted in all mainland French regions.

The species has a hidden advantage in that it can survive longer in areas with low water levels, so is less impacted by any shortfall in rain during early autumn. 

In addition, tiger mosquito eggs are more frost-resistant than their Culex counterparts, meaning eggs can survive the winter period much easier. 

Bites from any mosquito species risk transmitting their respective viruses regardless of the season.

Therefore, it is important to both avoid bites wherever possible, kill mosquitoes you do see, as well as reduce any potential breeding grounds for mosquito eggs.