When I lived in a rural area, I tried to count the many woolly
bear caterpillars I saw each autumn. One
season my tally reached over a hundred before I gave up! Now that I live in a small city, I have yet
to see a single woolly bear. What will I
use to predict the winter – and should I have even used woolly bears in the
first place?
From Bears to Tigers
– Oh My!
Found in North America, the
banded woolly bear caterpillar is the larva of the Isabella tiger moth. We see them "scampering" around in the fall
because they have recently emerged from eggs.
Woolly bears eat plants and prefer low vegetation, which is probably why
I haven't seen them in the city – despite living near a wooded bike path and "forever
wild" area.
Over the winter, they hide under leaves and create their own
protection from the freezing weather; it's called cryoprotectant and it
actually prevents them from freezing!
Glycols are commonly used in preventing ice formation. Similar stuff is also used in food – ever
wonder why your ice cream isn't ice?
In the spring, woolly
bears warm up, eat, pupate, emerge from their cocoons, and turn into Isabelle
tiger moths.
Folklore or Weathermen?
Where I'm from, kids grow up trying to predict the weather
based on the length of the brown middle section of a woolly bear. Folklore says, the longer the mid-section,
the shorter the winter and vice versa.
From 1948
to 1956, American Museum of Natural History insect curator, Dr. C. H.
Curran, studied woolly bears in Bear
Mountain State Park, New York. He found that Woolly bears have 13 band
segments in a black-brown- black pattern.
During this time period, the caterpillars averaged 5.3 to 5.6 segments
of brown bands – more than a third of their body length. The winters during the same period happened
to be milder than average.
According to almost all of the other sources I reviewed,
this theory is untrue. Band length can
vary based upon a number of factors, including but not limited to:
- Age – the black outer bands decrease as the caterpillar
matures
- Color variation – even larvae from the same
clutch can have different brown band length from the start
Still, the woolly bear is important to many people. Take, for example:
- The Woollybear Festival in Vermillion, Ohio, which includes a
costume contest.
- The Woolly Worm Festival in Beattyville, Kentucky
– including a human vs. woolly bear race.
- The Woolly Worm Festival in Banner Elk, North Carolina – the
caterpillar that wins the featured race predicts the upcoming winter.
- Oil
City, Pennsylvania's
"Oil Valley Vick" is hoping to predict the nation's winter just like
Punxatawney Phil predicts springtime.
- Hagerstown,
Maryland holds an annual contest
to find the cutest and cuddliest, as well as the biggest and woolliest
caterpillars.
Resources:
http://en.wikipedia.org/wiki/Pyrrharctia_isabella
http://en.wikipedia.org/wiki/Cryoprotectant
http://www.almanac.com/content/woolly-bear-caterpillars-weather-predictors
http://www.cirrusimage.com/woolly_Bear_Caterpillar.htm
http://www3.islandtelecom.com/~oehlkew/indexarc.htm
http://www.enature.com/fieldguides/detail.asp?recnum=BU0165
http://www.herald-mail.com/?cmd=displaystory&story_id=232155&format=html&autoreload=true
http://blogs.woodtv.com/files/2008/10/terri-woolly-caterpillar.jpg
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Re: Woolly Bears as Winter Indicators - True or False?
