Friday, October 16, 2009

Woolly Bears


I did a little online research on Woolly Bears last week after I found so many at SCWMA. I’m sure many of you are familiar with the little black banded fuzzy caterpillars that have the reputation for telling the coming winters weather. While that is fun to speculate, what I found was far more interesting to me. It seems the Woolly Bear caterpillar (Pyrrharctia isabella) larva form of the Isabella Tiger Moth can make its own antifreeze called "cryoprotectants" and chemicals to keep their body fluids from freezing. Wood frogs do this but I had no idea that this caterpillar can do that as well. I haven’t found much about how that happens other than that it does. Currently the ones we are seeing are racing to find a good place to hide for the winter, such as under bark, in crevices and in wood piles.


The other neat thing I learned from an article by Ker Than, in the March 13, 2009 National Geographic News, is it “the first clear demonstration of self-medication among insects”. Elizabeth Bernays of the University of Arizona and other members of her team have discovered that “in the spring, parasitic flies lay their eggs inside woolly bears. When the fly larvae hatch, they feed on the innards of their hosts before exploding out of their abdomens. But when infected caterpillars eat leaves from Senecio genus such as ragwort, the animals get bellies full of drugs called alkaloids.” They don’t know if the alkaloids kill the eggs directly or just boost the woolly bears’ immune system. I thought that was an amazing little unknown fact.


Most of us know them as the fuzzy things that curl up in a ball when we pick them up. They don’t hurt most people but there have been occasion of people who are allergic to the hairs. I wonder if the same people are allergic to wool. Just a thought. I could go on and on about their life history but I just wanted to bring those two unique facts to your attention. They have antifreeze in the winter and can self medicate; both useful abilities.


See more interesting critters at Camera Critter.

14 comments:

Wanda said...

Those are interesting facts new to me Cheryl...which I am going to pass on to my grandchildren.

storyteller said...

Hmmm ... I didn't know these things so I appreciate the info ... LOVE these photos! Mine's up too ;--)
Hugs and blessings,

Crafty Gardener said...

I recently did a post about the wooly bear caterpillar also. It was fascinating to discover facts about them.

Oskar said...

Those look very cute an cuddly. Thank you for stopping by my blog and leaving me such a nice comment about my eyeshine.

Adrienne in Ohio said...

Very interesting post, Cheryl! I always look forward to seeing these critters in the fall. My nephew had one all curled up in his hand last week. It made me smile and remember my own childhood.

eileeninmd said...

I've been seeing the woolly bears.Thanks for the woolly bear facts some is new to me. Thansk for sharing your critter.

Santa and Minnie said...

I don't know if we have them wooly bears here in Malaysia since we have hot weather here all year round.

Last week, I did a post on a caterpillar that we found here but I couldn't find any info on that little guy on the net. Thought you could help enlighten us.

Please take a look at that little guy at http://santa-ms.blogspot.com/2009/10/creepy-crawly.html

Thanks
- Diana

Woodswalker said...

Isn't nature amazing? I didn't know about that self-medicating strategy. I had heard about the antifreeze-for-blood strategies in a number of creatures, including the Mourning Cloak butterfly that winters over as an adult. This strategy allows their bodily fluids to supercool without forming crystals that would destroy their cell walls. One thing, though: if they get bumped or jarred, they instantly freeze. So they have to find very snug quiet spots to spend the winter.

Teena in Toronto said...

Nice shots!

I played too :)

Samson said...

Interesting facts, its all new to me so thanks for sharing... thanks for your comments on my blog, have a great weekend :)

Joy said...

They are really some of the most curious creatures!

magiceye said...

so interesting!
amazing nature!

kate said...

WOW! more cool facts learned from your site! keep them coming! I LOVE it! -kate

Carolyn Ford said...

These are colorful little critters with a bigger story than I imagined! Thank you for the new info! Great post!