Bzzzz

During NJ’s all-too-short summer I spend quite a lot of time outside in the early hours of evening. This is something I did less frequently as a kid. I liked the warm night summer air back then, to be sure, but didn’t much care for the insect life. That childhood home was in a valley near lots of water; the area is called Brookside for a reason. I presently live only 5 miles (8 km) from there horizontally while the vertical distance is a couple hundred feet (60 meters) higher. The change in elevation makes all the difference when it comes to mosquitos, which prefer the lowlands. Mosquitos might seem a minor complaint, but going inside begins to seem like a very good idea when constantly swatting them while telltale high-pitched buzzes around the ears promise more bites to come. While mosquitos are not entirely absent in my current location, they are rare. Bears are more likely to prompt a decision to go inside than they are, and bears don’t show up very often.

There was a time, however, when even the fairly low bite rate I currently experience would have posed a notable risk. We tend to forget just how much of the US as far north as New England was once infested by malaria, dengue, yellow fever, and other mosquito-borne diseases. During the 1920s, when the US population was a third of its current size, 1,200,000 Americans caught malaria. This was an improvement over the 19^th century rate. (My dad contracted malaria in the 1940s – also tinnitus from the quinine treatment – but that was in India during WW2.) Some progress was made against the disease in the early 20^th century, but efforts were stepped up after WW2 with the National Malaria Eradication Program. According to a CDC website “it consisted primarily of DDT application to the interior surfaces of rural homes or entire premises in counties where malaria was reported to have been prevalent in recent years… It also included drainage, removal of mosquito breeding sites, and spraying (occasionally from aircrafts) of insecticides. Total elimination of transmission was slowly achieved. In 1949, the country was declared free of malaria as a significant public health problem.” Nature rarely lets a handy virus vector such as the mosquito go unutilized however. Zika and West Nile viruses, among others, have secured a limited but stubborn foothold in the US in recent decades.

In his microhistory (a look at history in terms of a single component) Mosquito, author Timothy C. Winegard reminds us that globally the mosquito remains humanity’s deadliest predator, killing an average of 2,000,000 people per year since 2000. More accurately, the diseases they transmit kill people; in addition to those mentioned, these diseases include St. Louis, Japanese, and Equine encephalitides along with chikungunya and Mayaro. By comparison, the average annual toll from homicide (including war) since 2000 is 475,000. Snakes kill 50,000, dogs 25,000, crocodiles 1000, lions 100, and sharks 10. It is common for microhistorians to overstate their cases (the “to a man with a hammer everything looks like a nail” phenomenon), and Winegard is no exception, yet there is no doubt that mosquito borne diseases have had a profound effect on demographics, empires, war, and colonization from ancient times to the present. Winegard’s book is as good a summary as any for the general reader. (The armchair entomologists out there will be harrumphing that there are different species of mosquito that vary in their effects on human health; this is true, and the author covers this point, too.)

Mosquitos that look identical to modern ones existed 150,000,000 years ago – one premise of Jurassic Park that wasn’t fanciful. Humans have been swatting them since the genus Homo split off from the other great apes. People learned early on that swamps where mosquitos were thickest were not just unpleasant but unhealthy. Sumerian tablets 5200 years old describe malarial symptoms and blame the god Nergal, depicted as a mosquito-like being. Egyptian records also describe malaria, calling it swamp fever. Herodotus in the 5^th century BCE describes Egyptian mosquito nets in sleeping quarters. The Indian physician Sushruta in the 6^th century BCE also describes malaria; he squarely blames mosquitos and even distinguishes five species of them: “Their bite is as painful as that of a serpent and causes diseases.” The Romans wrongly thought disease was spread by “bad air” (which is what “malaria” means) but correctly identified swamps and stagnant water as risky. It wasn’t until the late 19^th century that the germ theory of disease finally explained how mosquitos vector diseases, even though the suggestion that they somehow do had been made many times before over millennia.

The mosquito was never in danger of extinction even at the height of the war against it, but nowadays more circumspect use of pesticides and the protection of wetlands are boosting their numbers again. In the 21^st century malaria vaccines have been developed, in part with funding from the Gates Foundation, which committed 2 billion dollars to malaria research. So far they seem to be no more than 39% effective, declining to less than 5% after seven years, but that is at least something. A novel approach to combatting mosquito-borne illnesses is to genetically modify mosquitos to not carry them. If this can be done and enough of them are bred, they will spread the traits through the general mosquito population. Even this can be no more than stop-gap however, since diseases will adapt in turn. What can one say but that if the mosquitos outlived the dinosaurs they are pretty certain to outlive all of us, too.

But not tonight. Tonight will be another warm July night in these parts and I expect to enjoy it sans any high-pitched buzzing. If I hear a growl though, I’m going inside.

Nina Simone – Funkier Than a Mosquito's Tweeter