- Scientists set out to figure out why mosquitoes love the taste of blood so much, and how they can detect blood in the first place.
- Using different mixtures and concoctions, the team determined that it’s actually the needle-like stylet that the insects suck with that does the “tasting.”
- It’s packed with neurons that detect specific ingredients of blood and trigger the intense sucking action.
I live in a state where mosquitoes are a huge problem for several months of the year. I also seem to have been blessed with particularly tasty blood, as the annoying little bugs always flock to me while leaving my wife and friends largely untouched. It’s weird, and I’ve always wondered what makes a mosquito prefer my blood — or blood in general — to other things it could be eating, like sugar-rich nectar.
A new study published in the journal Neuron takes a look at this phenomenon very closely in the hopes of determining what it is about the blood that makes it so tasty to mosquitoes. As it turns out, there are some very complex things happening in the needle-like stylet of mosquitoes that triggers them to suck as hard as they possibly can.
The scientists tested female mosquitoes — those are the ones that bite you — with various concoctions to see how they responded. They tested sugary mixes like nectar as well as different “blood recipes” that contained some components of human blood in different concentrations. They discovered that while the mosquitoes can taste and drink nectar, they don’t slurp it up with the same fervor that they do blood.
“When a female mosquito punctures the skin, she sucks so hard that the capillaries sometimes collapse,” Leslie Vosshall of The Rockefeller University, co-author of the study, said in a statement. “It’s a behavior she specifically reserves for blood.”
In testing different blood cocktails, the team found that neurons in the mosquito’s stylet activate when they encounter different components of blood. Some are activated by salt and others by sugar, but blood is an entirely different story. Even when using mock blood in combination with carbon dioxide in the air (a trigger that tells mosquitoes they’re feasting on a human) and heat, the mosquitoes weren’t fooled.
However, when the full list of faux blood ingredients was combined — glucose (sugar), salt, sodium bicarbonate, and adenosine triphosphate — the mosquitoes began guzzling the liquid at a breakneck pace. The neurons that respond to each of these ingredients must all be triggered before the mosquito will truly dive in for a full-belly meal.
This is particularly interesting because it means that the needle-like appendage that mosquitoes carry around is actually the thing doing the “tasting.” That’s something that wasn’t necessarily expected, and it’s a pretty remarkable evolutionary twist. As the scientists say, it’s essentially “a syringe that can taste blood.”
