Hiking Challenges

Mosquitoes

The exact mechanisms that mosquitoes use to find their victims are not fully understood, but it appears that mosquitoes use a combination of sight, smell, and heat to find someone to bite. During daylight hours a combination of movement and dark-colored clothing may attract mosquitoes that are some distance away. As mosquitoes get closer scientists believe that scent plays a larger role in mosquitoes finding their prey. Two scents given off by hikers known to attract mosquitoes are carbon dioxide and lactic acid. Fragrances from perfumes, soaps, lotions, etc. may also attract mosquitoes. As mosquitoes get very close to their prey it is believed that body temperature and moisture also serve as attractants.

The most effective mosquito repellent currently known is DEET. It works by interfering with the mosquito's chemical receptors. Generally a potency of between 10% and 35% is adequate. For detailed information on how DEET works, how to apply it, and how other repellents compare refer to the excellent article from the Annals of Internal Medicine entitled Mosquitoes and Mosquito Repellents: A Clinician's Guide in the link section below.

West Nile Virus

Beginning by about 2002 or 2003 the mosquito born West Nile Virus has become a serious problem for both people and animals. The health threat is serious enough that the federal Centers for Disease Control and Prevention have devoted some web pages to this problem. This information can be found at CDC - West Nile Virus.

Basically this is a virus that can be transmitted to humans by mosquito bite for which there is no vaccine or easy cure. People in generally good health may recover from the virus on their own, but people over 50 or in any kind of weakened state should take extra precautions to avoid getting bit.

For hikers this means avoiding areas known to have a high incidence of the disease if possible, to wear mosquito proof clothing (long pants and long-sleeved shirts) when mosquitoes are out, and to use mosquito repellent on exposed skin when they are present.

Links to further information on the Internet:

Mosquitoes and Mosquito Repellents: A Clinician's Guide

Ohio State University Fact Sheet on Mosquitoes

National Park Service Information on Mosquitoes

University of Arizona Mosquito Information

For even more information:

Mosquito: A Natural History of Our Most Persistent and Deadly Foe by Andrew Spielman Sc.D., Michael D'Antonio