Here’s how to deal with this problem when you’re observing.
This female mosquito is about to gorge itself on human blood.
Credit: JJ Harrison/WikiMedia Commons
While mosquitoes will attack whoever is handiest, they prefer adults to children, women to men, and pregnant women most. (They find ovulating women more attractive than those menstruating.) Movement attracts mosquitoes, so swatting at them is a good way to get them swarming around you. Contrary to popular belief, colors of clothing are not important to mosquitoes because the other attractions are so much stronger.
These insects don’t like the heat of the day, so solar observers tend to be safe from them. They’re most active around dawn and dusk. They hunt by using odor receptors on their antennas to “smell” for carbon dioxide, which all observers breathe out, and perspiration, which can happen for a variety of reasons, like when we’re having trouble making a critical observation.
How to deal with these bugs
Lotions containing citronella (0.05 percent or 0.1 percent) are used to repel mosquitoes. More effective is a lotion or spray containing DEET, the acronym for N, N-diethyl-meta-toluamide. Use products with no more than 34 percent DEET (10 percent for children age 2 or older) because higher concentrations can cause serious toxic reactions. Never use DEET on children under 2, pregnant women, or on children’s clothing or bedding.
While most people apply repellent only to exposed skin, experts suggest treating clothing as well. Most fabrics are only 1 millimeter thick, if that, but a mosquito’s proboscis (its elongated sucking mouthpart) is 2 millimeters long and can easily penetrate clothing, especially clothing that clings to the skin.
DEET won’t keep a mosquito from approaching, but it can stop her (all mosquitoes that suck blood are female) from biting by jamming the cells in the insect’s antennas that are sensitive to lactic acid.
For home control, so-called “bug zappers,” which attract insects with UV light, is the most popular and least effective. In a recent study by the University of Delaware, only 31 of 13,789 (0.2%) insects trapped were female mosquitoes or biting gnats. Another study found that zappers could spread bacteria and viruses up to six feet away. Bottom line: Don’t waste your money on any electronic method that says it will control mosquitoes.
For control around your backyard observatory, mosquito coils (a type of incense), citronella candles, and citronella oil lamps do a reasonable job of keeping mosquitoes away for several hours. Make certain that you are not in direct view of the light these items emit.
