Watch out for trick-or-skeeters this Halloween.
US researchers may have discovered the real reason mosquitoes crave our blood so much – because they taste like candy.
“We think the taste of blood in mosquitoes is a completely unique experience,” said Leslie B. Vosshall, Ph.D., of Rockefeller University in New York. The Howard Hughes Medical Institute researcher led the study published Monday in the journal Neuron.
The bloody study found that the Epicurean parasites, which are able to detect a combination of at least four different substances in the blood, taste “salty and sweet” a la salted caramel, according to the study. Think how a human tongue can distinguish between salty, sweet, bitter, sour, and umami flavors.
Omnivorous female mosquitoes use their special taste buds to differentiate between the nectar they consume for energy and the blood they drink before laying eggs. They even have separate mouth parts for every occasion – a “sweet tooth” for sugar and a syringe-like stylet that penetrates the skin and extracts plasma, according to the new study.
To test the bloodsuckers’ taste buds, the researchers equipped genetically engineered mosquitoes with a fluorescent tag that lights up when a neuron that corresponds to a particular taste is activated. They then fed them real blood and a mixture of glucose, salt, sodium bicarbonate (found in both blood and baking soda), and ATP, an energy-boosting compound.
“ATP is that special mysterious stuff that tastes like nothing to people, but it has to be incredibly exciting and rewarding for the mosquito,” says Vosshall, who tried it himself.
Scientists discovered that about half of the cells responded to blood – both real and imitation – while the other half responded to nothing, the Daily Mail reported. They concluded that the beetles can identify blood so well that, according to Neuron, they can distinguish it from nectar “at the very first level of sensory recognition”.
And while both humans and mosquitoes can reportedly feel both the salty and sweet flavors in the blood, Vosshall speculates that “the whole experience is definitely different” for a mosquito. She compares the blood-searching abilities of insects with “the ability of honeybees to see ultraviolet and bats to hear ultraviolet sounds”.
Despite their complex palate, mosquitoes are not “picky” when it comes to selecting human prey, according to Rockefeller’s Veronica Jové, who led the unorthodox taste test in Vosshall’s laboratory. “We’re all tasty enough for a mosquito,” she said.
Scientists hope that understanding mosquitoes’ taste buds will help them develop drugs that prevent them from biting people and transmitting diseases. Vosshall even suggested using a drug that would make us less tasty for the beetles.
“If mosquitoes couldn’t recognize the taste of blood, they couldn’t theoretically transmit disease,” said Jové.