How do insects survive in a frigid climate?

Have you ever wondered about other animals and life forms on our planet? How about insects like the one pictured above?

Of course you have. If you live in a frigid climate such as I do (Canada), then survival for many species of life, takes on new meaning. There are some remarkable ways in which life forms survive the harsh winters in Canada.

I learned how insects survive our winters when I took a course in entomology at the University of Alberta here in Edmonton. Our professor, Dr. Hemming, fascinated all of us when he told us that some insects actually make what scientists consider to be an "antifreeze" in their bodies,so their blood and critical aspects of their body do not freeze solid in the cold winters of Canada.

Why am I telling you this? Because when browsing the online edition of the  New York Times today, I came upon and article entitled "When Built-In Antifreeze Beats a Winter Coat", which you can read by clicking on the following link:

http://www.nytimes.com/2010/01/19/science/19creatures.html?ref=science

In this article, Sean B. Carroll, a molecular biologist and geneticist, who has authored a book entitled, " “Remarkable Creatures: Epic Adventures in the Search for the Origin of Species.” states:

"The threat to life at low temperatures is not really cold, but ice. With cells and bodies composed mostly of water, ice is potentially lethal because its formation disrupts the balance between the fluids outside and inside of cells, which leads to their shrinkage and irreversible damage to tissues."

"Insects have therefore evolved all sorts of ways to avoid freezing. One strategy is to escape winter altogether. Butterflies like the monarch migrate south. A great solution, but this is a relatively rare capability. Most insects remain in their local habitat and must find some other way to avoid freezing. They evade the ice by crawling into holes or burrows below the snow cover and frost line, or, as some insect larvae do, by overwintering on the bottoms of lakes and ponds that do not completely freeze."


"But many insects, and other animals, defend themselves against direct exposure to subfreezing temperatures through biochemical ingenuity, by producing antifreeze."

"The first animal antifreezes were identified several decades ago in the blood plasma of Antarctic fish by Arthur DeVries, now at the University of Illinois, and his colleagues.

"The ocean around Antarctica is very cold, about 29 degrees Fahrenheit. It is salty enough to stay liquid several degrees below the freezing temperature of fresh water. The abundant ice particles floating in these waters are a hazard to fish because, if ingested, they can initiate ice formation in the gut and then — bang, you have frozen fish sticks. Unless something prevents the ice crystals from growing.That is what the fish antifreeze proteins do. The tissues and bloodstream of about 120 species of fish belonging to the Notothenioidei family are full of antifreeze. These proteins have an unusual repeating structure that allows them to bind to ice crystals and to lower the minimum temperature at which the crystals can grow to about 28 degrees. That is just a bit below the minimum temperature of the Southern Ocean and about two full degrees lower than the freezing point of fish plasma that does not have antifreeze. This small margin of protection has had profound consequences. Antifreeze-bearing fish now dominate Antarctic waters."

"But insect innovation goes beyond antifreeze. Biologists have discovered another strategy for coping with extreme cold: some bugs just tolerate freezing."

In the most northern climates, like the interior of Alaska, midwinter temperatures fall as low as minus 60 degrees Fahrenheit, and snow cover and subzero temperatures can last until May. At these extreme temperatures, most insects are bugsicles. The Alaskan Upis beetle, for example, freezes at around minus 19 degrees. But, remarkably, it can survive exposure to temperatures as low as about minus 100 degrees.
To tolerate freezing, it is crucial that insects minimize the damage that freezing (and thawing) would normally cause.
Insects have evolved a variety of cryoprotective substances. As winter approaches, many freeze-tolerant insects produce high concentrations of glycerol and other kinds of alcohol molecules. These substances don’t prevent freezing, but they slow ice formation and allow the fluids surrounding cells to freeze in a more controlled manner while the contents of the cells remain unfrozen.
For maximum protection, some Arctic insects use a combination of such cryoprotectants and antifreezes to control ice formation, to protect cells and to prevent refreezing as they thaw.

To read the remainder of this article please click on the following link:

http://www.nytimes.com/2010/01/19/science/19creatures.html?ref=science

Time for another question, Can you name the largest land animal in Antarctica?
You can learn the answer to this question by clicking on the following link:

http://ezinearticles.com/?Belgica-Antarctica-The-Insect-That-Uses-Antifreeze-to-Survive-Antarctica&id=1749180


You can learn more about how insects survive harsh winter climates by reading the information provided at the following websites:

http://insects.about.com/od/adaptations/p/wintersurvival.htm

http://www.coopext.colostate.edu/4dmg/Pests/winter.htm

http://northernwoodlands.org/outside_story/article/how-insects-survive-the-cold-of-winter/

http://www.amentsoc.org/insects/fact-files/overwintering.html

http://www.physorg.com/news178391046.html



http://ezinearticles.com/?Belgica-Antarctica-The-Insect-That-Uses-Antifreeze-to-Survive-Antarctica&id=1749180

http://www.sciencecentric.com/news/article.php?q=07053102

http://www.taiga.net/yourYukon/col336.html

Here are two interesting videos which show how some insects survive harsh winters:

Mantids overwinter as eggs in foam cases.

Photo: © Whitney Cranshaw, Colorado State University, Bugwood.org