New 'super mosquito' discovered in Mali

A new “super mosquito” has been discovered in Mali and is being researched by a team of researchers and scientists at the University of California-Davis.

Interbreeding among two malaria mosquito species in the West African country has resulted in a new mosquito hybrid that's shown to be resistant to insecticide-treated bed nets.

"It's 'super' with respect to its ability to survive exposure to the insecticides on treated bed nets," UC Davis medical entomologist and research team leader Gregory Lanzaro said.

Lanzaro is also director of the Vector Genetics Laboratory and professor in the department of pathology, microbiology and immunology in the School of Veterinary Medicine. He has researched mosquitos in Mali for 24 years with Anthony Cornel, an associate professor in the UC Davis department of entomology and nematology.

The findings were published in a recent issue of Proceedings of the National Academy of Sciences.

"(The results) provide convincing evidence indicating that a man-made change in the environment — the introduction of insecticides — has altered the evolutionary relationship between two species, in this case a breakdown in the reproductive isolation that separates them," Lanzaro said. "What we provide in this new paper is an example of one unusual mechanism that has promoted the rapid evolution of insecticide resistance in one of the major malaria mosquito species."

A major malaria vector called anopheles gambiae is interbreeding with isolated pockets of another malaria mosquito, A. coluzzii, and is now considered a separate species.

The insecticide resistance came as no surprise to Lanzaro.

"Growing resistance has been observed for some time," Lanzaro said. "Recently, it has reached a level at some localities in Africa where it is resulting in the failure of the nets to provide meaningful control, and it is my opinion that this will increase."

Lanzaro said insecticide-treated nets save many lives in Mali alone and the World Health Organization's World Malaria Report shows that deaths from malaria worldwide have decreased by 47 percent since 2000, with much of that credited to the bed nets.