The colony was picky — it wouldn’t feed on anesthetized mice or drink from a container covered with a membrane. These mosquitoes retained their behavior from the wild: They wanted blood straight from a human, and only in darkness. So [researcher Sam] Rund would feed them for about 15 minutes at a time. He’s a pro at it now; after the first two months of feeding mosquitoes, his body got used to it.
“Once you’ve blood-fed enough mosquitoes for a long enough period, you become tolerized, so your immune system, kind of, stops overreacting,” Rund said.
For researchers investigating how mosquitoes spread deadly diseases such as malaria, dengue fever, yellow fever and chikungunya, laboratory protocols sometimes involve “donating” blood to the cause. And the cause is urgent — mosquito-borne pathogens kill millions of people annually all over the world.
[Doctoral student Veronica] Jové and her colleagues have found that there are four essential ingredients in blood that mosquitoes go after: sodium chloride; adenosine triphosphate, which is the molecule of energy produced by cellular mitochondria; sodium bicarbonate, which is a major buffer in blood; and blood glucose. Based on the activity of sensory neurons in that sharp stylet, it appears they are more interested in the salty component of blood than the sweet, but all of these flavors combine to create the taste that female mosquitoes go after.