The Challenge of Aedes Albopictus

The tiger mosquito, Aedes albopictus, poses a growing public health concern due to its ability to transmit diseases like dengue fever and chikungunya. Guillaume Lacour, scientific manager of the company Altopictus, based in Bayonne, France, explains the complexities of vector control and the tools available to combat this invasive species. Altopictus is commissioned by the Regional Health Agency (ARS) of Occitanie and local communities to treat infested areas.

It’s critically important to note that Altopictus primarily works through public contracts with ARS and local communities and does not respond to individual requests for mosquito control.

Preventative Demoustication: A delicate balance

Despite public demand – Lacour notes he hears requests for action “every day” – widespread preventative demoustication is not necessarily the most effective approach. The reliance on pyrethrinoid insecticides carries the risk of developing mosquito resistance. “A single effective active substance is now approved, in the class of the Pyrethrinoids. If, by dint of treatments, the mosquito became resistant, it would be vrey difficult to act,” Lacour explains.

This concern is supported by emerging research showing the presence of resistance alleles – variations in DNA sequences – in tiger mosquito populations, particularly in the PACA region of France, which has experienced indigenous cases of chikungunya, and also in Occitanie.

Evaluating Mosquito Traps

individuals seeking to control mosquito populations have an increasing number of traps available.however, Guillaume Lacour cautions that many are ineffective, and there is currently no standardized quality labeling system.

Among the traps that have demonstrated efficacy are those manufactured by Biogent and Mosquito Magnet. These traps, typically placed outdoors, serve a dual purpose: they directly reduce mosquito numbers and encourage homeowners to eliminate standing water sources – a crucial preventative measure.

“If there is only one water point, mosquitoes will go to him,” Lacour emphasizes. The cost of these traps ranges from approximately 25 euros to 2000 euros.

Sterile Insect Releases: A Promising Strategy

Currently, the most readily available methods for individual protection include wearing protective clothing, using mosquito nets, and applying repellents. However, Altopictus highlights that each treatment – 171 since May, triggered after surveys of 240 hotspots – represents a collective failure of preventative measures. “This means that prevention has not worked. But we have always managed to neutralize the epidemic departures,” Lacour notes, acknowledging the importance of community collaboration. “It is essential because a shock action, when intervening, loses its effectiveness in a few days.”

For communities, sterile insect releases offer a more substantial intervention. These releases can reduce mosquito populations by 60% to 90%, as demonstrated in a recent trial in the commune of Brives-la-Gaillarde, in southwestern france.