as Arizona and Nevada, have robust populations that can wreak havoc. In short, there is almost no escaping them, so you need to know how to fight back.
Of course, Brazil’s many mosquito species won’t necessarily ruin your vacation in Rio. After all, species numbers don’t say much about population numbers. A case in point: Alaska and Minnesota are home to far fewer species, but they definitely boast more than their fair share of individual critters in “skeeter season.” Unsurprisingly, both Alaska and Minnesota have mosquitoes named after them.
The Mosquitoes to Worry About: The “Flying Syringes”
All mosquitoes belong to one large family of insects—Culicidae. This family consists of two large groups, which are called subfamilies: the Anophelinae (480 species) and the Culicinae (3,000 species). Some species don’t bite humans at all, but a good number are serious pests and a few troublemakers are responsible for spreading serious diseases.
In particular, three groups of mosquitoes are responsible for the vast majority of mosquito-borne diseases. These bad apples are often called the “Flying Syringes.”
Because of their medical importance, it’s helpful to be familiar with them. As it happens, these three groups also include some of the primary pest species—so even if they don’t make you sick, they might still ruin your barbecue.
Culex
Anopheles
Aedes
Anopheles mosquitoes are members of the Anophelinae subfamily. One genus of the Anophelinae mosquitoes—the genus Anopheles—is notorious for spreading malaria. In all, there are 12 species of Anopheles in North America7.
Both the Aedes genus and the Culex genus are members of the Culicinae subfamily. There are 11 species of medically important Aedes in North America8, and 9 species of medically important Culex.
The Aedes mosquitoes spread yellow fever and Dengue fever.
Culex mosquitoes spread West Nile, a number of types of encephalitis9 and several parasitic diseases.
The good news? Cases of malaria, yellow fever and Dengue fever are mercifully rare in the U.S., and those infected have usually traveled abroad. Other diseases—including West Nile—still remain a serious concern, however.
What’s in a Name?
The word Anopheles (a-NOF-o-leez) comes from the Greek word anōophelōes, which translates to “useless.10”
The word Aedes (AY-deez) also comes from Greek, from the word aōedōes, which translates to “unpleasant.11”
The genus name Culex (CUE-lex) is far less colorful and simply means “gnat” or “fly” in Latin12.
Even Mosquito Researchers Get Annoyed at Mosquitoes
Some mosquito researchers clearly had some pointed (ha?) opinions about mosquitoes. Want proof? The species names they chose say it all; you’ll probably recognize most of these root words, all of which are used in English: vexans14 and inundatus and abominator and excrucians and tormentor and horrida. None of them have positive connotations.
Some biologists literally agree with Anopheles’ scientific name and think that mosquitoes are worthless, even calling for the outright eradication of mosquitoes. They argue that the ecosystem would likely be relatively unaffected13.
Four Phases of Life
Like butterflies, ants and many other insects, mosquitoes go through four general stages of life: they start life as an egg, which hatches into a larva. After feeding, the larva pupates, where it transforms into an adult.
Where Do Mosquitoes Lay Eggs? Pretty Much Everywhere
Female mosquitoes lay their eggs on or near water, or in areas that will soon be exposed to water. As you might expect, that encompasses much of the U.S., and with over 150 species in the country, there’s a great deal of variation among mosquitoes.
Very generally speaking, there are two types of mosquitoes—floodwater mosquitoes and freshwater/stagnant water mosquitoes. These names are informal, and since mosquitoes are quite opportunistic when depositing eggs, some species undoubtedly fit in both categories. Still, these categories are enough to give the layperson an idea of where mosquitoes lay their eggs—and how one can avoid giving mosquitoes places to deposit eggs.
Floodwater mosquitoes
As their name suggests, floodwater mosquitoes (which includes important Aedes species) lay their eggs in areas that are damp or that will be inundated by water, such as salt marshes or riverside forests. The eggs need to be inundated by water before they hatch, but reduction of dissolved oxygen in the water is the most important factor for egg hatching15. When levels drop beyond a certain point, the eggs hatch. This ensures that the larvae will be born into the shallow, food-filled areas where the larvae thrive. These mosquitoes often become a scourge after river flooding or the storm surge of a hurricane.
Freshwater and Stagnant Water Mosquitoes
Some species, like the malaria-bearing Anopheles mosquitoes, only lay eggs on freshwater, whereas the notorious pest Culex pipiens lays eggs16 in stagnant water, everywhere from cesspits and plant pots to hoofprints in cow pastures. The invasive Asian tiger mosquito will deposit eggs nearly anywhere it can—and doesn’t venture far from where it hatches, so if a female of a pest species deposits eggs in the birdbath on your deck rail, you’re certainly on the dinner menu17. Perhaps surprisingly, flowing streams and deep ponds and lakes are often less ideal environments for most mosquito species, as they have less food, too much turbulence and more predators.
How opportunistic are mosquitoes when finding a place to lay their eggs? During a study in the 1930s, a cage holding research mosquitoes and eggs was inadvertently torn open. When the researchers returned and discovered the damage, they noticed that some mosquitoes had escaped, but wild females had entered the cage and laid additional eggs18 !
To make matters more complex, some mosquitoes are often referred to as “container” mosquitoes because they are found in a variety of natural or artificial containers. Mosquitoes found in natural containers are often referred to as “woodland” or “treehole” mosquitoes because they are found in wooded areas, and often deposit eggs near trees—or in cavities within them. When it rains, these holes fill in with water, and the eggs then hatch. There are many types of natural cavities—from rotting stumps to containers as specific as a particular type of pitcher plant. In fact, some mosquito species even lay their eggs in pitcher plants, which serve
