Human blood is an attractive source of food for mosquitoes. Even if some people are not that attractive to mosquitoes, some of these insects still risk everything to take a sip of your blood. What does human blood have that attracts mosquitoes? Scientists have been studying this subject. Here are the facts.
What the Scientists Discovered
Researchers found out that there are certain compounds in human blood that attract mosquitoes. This allows scientists to manufacture a drug that could mask this tantalizing flavor. A study team from Rockefeller University used modified female mosquitoes. The team wanted to find out which neurons became active whenever they tasted human blood.
It is important to note that the main food of mosquitoes is nectar. Female mosquitoes only need blood to nourish their developing eggs. Even if they only bite when they need to, their bite made them the deadliest animals on Earth. Mosquito-borne diseases kill about 500,000 people each year. Yellow fever, malaria, dengue, and Zika are life-threatening diseases that you can get from a mosquito bite.
The scientists tricked the mosquitoes during the study. They created a compound that consisted of sodium chloride, glucose, adenosine triphosphate, and sodium bicarbonate. This compound imitated the flavor of human blood. Scientists now know if the mosquitoes are in nectar-drinking or blood-drinking mode, based on which part of the proboscis that the insects use.
The genetically modified mosquitoes had fluorescent tags that glowed when the nerve cell was triggered during feeding. This allowed the scientists to track different nerve cells that shone whenever the mosquitoes had their meals. One subset of neurons was triggered by human blood. This happened when the mosquitoes consumed synthetic and natural blood meals. The scientists concluded that if the mosquitoes did not smell the blood, they would not be transmitting deadly diseases at all.
What This Means
Researchers believe that what they discovered will eventually give birth to oral mosquito repellents that would block the mosquitoes’ taste for nutritious human blood. But they also said that it could be almost impossible to understand what human blood really tastes like to these insects.
The Neurons That Work for Mosquitoes
When insects find a blood meal, they gorge. They pump vigorously as they feed from human veins. Female mosquitoes suck with so much strength that the capillaries they target collapse sometimes. This type of demeanor is only for blood meals.
Some researchers found out that there is a unique cluster of neurons in the stylet of female mosquitoes. These neurons do not pay attention to salty or sweet tastes alone. They activate only when the other blood components are present. This showed that the stylet has a programmed set of tastes to target.
There was a study that imitated the environmental elements that go with human blood. The scientists replaced the sheep blood with saline and sugar solutions but they did not pay attention to them. Female mosquitoes are very specific about what they feed on when it comes to sustaining their eggs.
The stylets seem to have neurons that are programmed to recognize the components that are unique to blood. Each human blood component triggered a specific cluster of neurons. But one cluster did not react. It only reacted when all the components were present. These neurons are the integrator neurons that combine the signals from the different components of taste. Integrators decide whether to activate the blood pump for blood and not for water or nectar.
Another study showed that female mosquitoes use two of their 60 glomeruli or nerve centers to pinpoint human odor. These two nerve centers detect undecanal and decanal chemicals that have a mild citrusy odor. Human odor has a rich amount of these two chemicals.
Human blood is a clear target for female mosquitoes. The neurons tell the insect if it is time to gorge or not. It seems that mosquitoes are picky eaters when it comes to blood. Perhaps they are more complex than we thought they were.