By Dan Zarlenga, Missouri Department of Conservation
Photo caption: Mosquito larvae, known as “wigglers”, hang at the water’s surface. Photo by Jim Rathert, Missouri Department of Conservation.
As you enjoy the outdoors during the warm months of August, sooner or later you’ll likely experience an encounter with a pesky mosquito. On what might seem an unrelated topic, have you ever wondered how the founders of the settlement that would become St. Louis chose this spot? The answer is at least partly in the insistent whine of that mosquito.
Missouri is home to about 50 different species of mosquitoes, all of which are members of the fly family. Most people know from personal experience that these insects feed on blood. Only female mosquitos require a blood meal though, from which they derive necessary protein to fuel their reproductive duties. Males feed mostly on flower nectar and aid in the process of pollination.
Females use the proteins from blood to develop anywhere from 100 to 400 eggs. The mother mosquito then looks for standing water into which to deposit those eggs. In just a few days, larvae called “wigglers”, emerge. For a week these worm-like wigglers hang near the water’s surface and breathe air through tubes in their abdomens. If threatened, they wiggle deeper into the water. After pupating for two or three days, the mosquitos transform into adults and mate. From there the females are off to find blood. The insect’s entire life cycle is just a few weeks.
Mosquitos do have the potential to carry diseases; in some parts of the world this includes viruses that bring West Nile, Zika, yellow fever, and dengue fever. Mosquitoes can also transmit parasites that cause malaria. This made the lowly insect a tiny tyrant that dictated human settlement.
The still waters of swamps and marshes provide ideal habitat for species of mosquitos that can harbor malaria. Historically however, people were not aware of this connection. They blamed the swamps themselves for causing malaria, because of septic air. In fact, the disease gets its name from the Latin mal aria, or “bad air”.
When establishing frontier settlements, pioneers throughout Missouri, and the country, went out of their way to avoid “malaria swamps”. The presence of these swamps held great influence as to the locations where people ultimately choose to settle.
For example, the town of Ste. Genievieve was originally built in the fertile Mississippi River floodplain. After the flood of 1785, it was moved two miles farther inland and uphill, to avoid the swampy and disease-prone conditions of the river bottom.
Even the founders of St. Louis itself were compelled to unwittingly pay deference to the humble mosquito. French and Spanish settlers chose to establish their settlements on the high river bluffs, which they saw as having better air. The settlers avoided the swampy lowlands along the water. These places are associated with an atmosphere of sickness and fevers. It was where the mosquitos ruled, the clandestine carriers.
Next time you feel the irritating bite of a mosquito, it’s probably not much comfort to know it’s only a mother gathering resources she needs to raise her young. But it might be fascinating to realize that you’re swatting at a tiny but historically-significant creature. An insect that influenced the founding of cities.