They say you should write about what you know, and right now (as I finish up a month-long stint in the Berkshires) what I know is mosquito bites. It seems like every time I’ve slathered myself in hydrocortisone cream another bite pops up somewhere else.
Fall of 2011 was a particularly bad mosquito season in western mass, and I expect this autumn to be even worse. It’s been even hotter than last year, and there’s been plenty of rain. Going through Ecology last fall meant that I spent the better part of the semester covered in itchy welts, and there was no relief until that freak snow storm in October (and thank goodness for that, because winter never really came) killed the last of the swarm.
- Why the biting?
Some (not all) species of mosquitos feed on blood. Even within these species, it’s always the females that bite; They need the proteins found in mammalian blood in order to produce eggs.
- Why the itching?
Mosquito saliva contains proteins that keep the blood from clotting, allowing them to feed. After the mosquito has left, our immune systems respond with antibodies. The reaction causes swelling and itching. You can use antihistamines or hydrocortisone to try to dull your body’s immune response, which will stop the itching, or you can make a paste out of water and meat tenderizer, which will break down the offending proteins.
- Am I going to die?
Probably not. Mosquitos can carry some really nasty diseases like West Nile, but (at least within the United States) most bites are harmless. Anecdotally, I had a doctor tell me last year that “half of the campus probably got West Nile” during that particularly bad season, but only one student I know of had symptoms that got him tested-and even he didn’t suffer the encephalitis that makes West Nile troublesome. Of course, everyone should know the symptoms and be on the lookout for possible infection, especially in young children and the elderly. You can read about how West Nile came to the US in this excerpt from Carl Zimmer’s A Planet of Viruses.
- What works to keep them away?
Repellants work by masking the scents that make us attractive to mosquitos. Carbon Dioxide is a big one, which is why pregnant women (who produce more CO2) tend to get bitten more. Lactic acid, which is produced by hard-working muscles, is another, which is why you’ll probably get bitten if you walk out of the gym on a summer day without taking a shower first. People who have recently consumed alcohol get bitten more as well. Certain blood types, immune systems, and even moods may also produce more attractive scents, but there isn’t any evidence that artificial scents from perfumes make you more visible to mosquitos.
I’m going to make a confession: I use DEET. Stomping around in marshes during high mosquito season makes it sort of a necessity, and the Environmental Protection Agency does claim that it’s safe when used as directed. The Center for Disease Control recommends Oil of Lemon Eucalyptus as well, but keep in mind that essential oils evaporate quickly, meaning you’ll have to reapply all day if you want the same effectiveness as a synthetic spray.
There’s been research on mosquito attractants that says Limburger cheese is as appealing to the bugs as human feet are (probably because of the bacterium they have in common), so I guess you could also throw a chunk of that in whatever direction you don’t want the mosquitos to go in. I’m sort of joking, but hey…whatever works, right?