Tiny but Dangerous: The Mosquitoes Spreading Zika
Feb. 2, 2016 -- They’re tiny. They attack with supreme stealth, biting in full daylight with no buzz and no sting. And they carry viruses that can be lethal to their preferred food source: us.
The Aedes aegypti, or yellow fever mosquito, killed more soldiers than guns did during the Spanish-American War. And now these black-and-white striped femme fatales -- only the females suck blood -- are causing misery through Central and South America as they pass the viruses that cause dengue fever, yellow fever, chikungunya and now Zika virus disease from person to person.
Their ancestors lived in the forest where they fed on all manner of warm-blooded creatures, but some time in recent history -- no one is sure exactly when -- the modern Aedesmosquito developed a preference for just one animal -- humans.
“They only live in association with humans. And they have all these physical and behavior adaptations to do it,” says Carolyn McBride, PhD. She’s an assistant professor of ecology and evolutionary biology at Princeton University who specializes in Aedes aegypti.
“They have an amazing ability to recognize human odor,” McBride says. “You can put on a lab glove and cut a little hole in the back so that just an inch of skin is exposed, and they’ll find it.”
Where They Hide Out
Experts who have spent some time studying Aedes mosquitoes are amazed at how well they’ve adapted to feeding on people.
Take, for instance, their habitat. They don’t have a lot of stamina in the air. Their flight range is just 300 to 600 feet. As a result, insecticidal sprays mostly don’t work on this breed, because it’s hard to catch them airborne.
To feed, they have to stick close to their intended targets, a.k.a. us. They live under decks, patio furniture, and in homes that don’t have cool air -- they don’t much like air conditioning. They especially love the drip trays that collect extra water under potted plants. But that’s not the only place you’ll find them.