Mosquitoes suckered in new malaria research

In the biggest lab breakthrough against malaria in years, scientists said they had identified odour molecules that baffle blood-thirsty mosquitoes. The molecules disrupt carbon-dioxide sensors that alert mosquitoes to exhaled breath, which signals the presence of a human nearby, the team reported. The work could lead to revolutionary but low-cost chemicals to confuse, deter or trap mosquitoes, it said. They could be invaluable in poor tropical countries, providing an alternative to DEET, a skin repellent that is expensive, needs repeat applications and is showing worrying signs of resistance.

“These chemicals offer powerful advantages as potential tools for reducing mosquito-human contact and can lead to the development of new insect repellents and lures,” said Anandasankar Ray, of the University of California, who led the study. Traps for mosquitoes already exist, in the form of dry ice, gas cylinders of carbon dioxide or propane combustion. But these gadgets are too bulky and far too expensive to be used for mosquito control. Future traps could be convenient and easily replenishable.

The odour molecules that they identified disrupt receptor cells for carbon dioxide located in tiny, antennae-like appendages close to the mosquito’s mouth. These receptors are activated by a whiff of carbon dioxide, triggering a signal in the brain that prompts the insect to fly upwind, following the puffs of CO2 until they reach its source. Mosquito also use heat sensors and sight to home in on their meal.