Tiger mosquitoes: why are they still so numerous?

Small, aggressive, diurnal… The tiger mosquito continues to ruin your life. “It’s incredible, I was stung again last night!” testifies Aouregan, 25 years old, living in the city center of Cahors. Nothing surprising for Guillaume Lacour, medical entomologist and scientific manager at Altopictus, a company specializing in the fight against the tiger mosquito in Occitania. The month of October was rainy, with temperatures still very mild: the conditions are ideal for tiger mosquitoes to continue biting. “A female tiger mosquito is capable of laying up to 200 eggs every four days!” explains the specialist. “The tiger mosquito likes the urban and peri-urban environment, it is a species subservient to man. We provide the preferential meal for females and all the containers present in our gardens and terraces provide conditions conducive to the development of larvae. 90% of larvae develop in our water tanks, cans and saucers!”

An autumn favorable to the development of the tiger mosquito

Since September, female tiger mosquitoes have constituted the stocks of the next generation. “The eggs laid at the moment are in diapause, in other words, in hibernation” specifies Guillaume Lacour. “It is important to know the habits of this mosquito well and adopt the right actions to effectively combat this species which moves little and does not exceed a radius of 150 meters! Unlike the common mosquito, the tiger mosquito bites during the day. But, locked in the house in the evening, with the light on, it will continue to bite While endemic species of mosquitoes favor ponds, ditches and marshes, the tiger does not thrive in large volumes of water. On the other hand, the tiger mosquito likes stagnant water and the slightest hollow object can become an egg-laying site. The female lays her eggs on the dry, vertical walls of all containers, a few millimeters above the water level.” continues the entomologist. “I insist, we are observing a phenomenon of demobilization of citizens. It is important to continue to raise awareness among the general public to fight against this species which is a vector of disease. This summer, we had 84 cases of dengue fever in mainland France!” But then how should we act?

The sponge with scraper: a simple solution to limit proliferation

“We must continue to clean the inside of all rainwater tanks like the barrels in our gardens.” advises Guillaume Lacour. “By cleaning these containers with a sponge on the scraper side, we detach and crush the eggs. This helps reduce the number of eggs that will spend the winter in diapause.” It is imperative not to forget to clean the water collectors or the gutter downpipes. Do not count on the presence of bats or birds to combat the tiger mosquito, they prefer larger, fatter insects. As for the traps offered in stores, Guillaume Lacour recommends those which are imagocidal, that is to say which kill adult mosquitoes. Knowing that the tiger mosquito only moves around very little, adopting simple actions around the home is the best way to limit their proliferation next spring.