Researchers in Mali have discovered a new hybrid mosquito -- a so-called "super mosquito" -- that is unaffected by bed nets treated with insecticides.

Thanks to manmade interventions like insecticide-laced mosquito nets, malarial infections have been nearly halved since 2000. But scientists with the University of California, Davis say that those same interventions have altered the evolutionary landscape, encouraging the sexual cooperation of two previously isolated mosquito species.

Anopheles gambiae -- one of the mosquito species most heavily responsible for the spread of malaria in West Africa -- has been mating with small pockets of another species, Anophele coluzzii.

"Growing resistance has been observed for some time," lead researcher Gregory Lanzaro, a medical entomologist at UC Davis, said of the new hybrid offspring. "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."

"It's 'super' with respect to its ability to survive exposure to the insecticides on treated bed nets," Lanzaro added.

Hybrid super bug or not, the scientists say it was only a matter of time before resistance to current strategies emerged.

Now, researchers will need to act fast to develop new insecticides and biological agents. Several mosquito-killing bacteria and fungi are already in the works, as are genetic manipulation techniques that experts say could kill or inoculate the mosquitoes' malaria-spreading capabilities.

The discovery of the new hybrid super bug is detailed in the latest edition of the journal PNAS.