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Word of the Week: Setae

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Welcome to Word of the Week! Stay tuned for a new word each Friday to amp up your nature vocabulary!

Setae [SEE-tee] (plural biology noun): Bristle- or hair-like structures found on the bodies of living organisms, especially invertebrates

This fun word comes from the Latin word “sēta” which means “bristle.”

When the temperatures cool down, the Woolly Bear caterpillars of High Park are on the move and busy searching for a safe place to settle down for the winter!

Woolly Bear caterpillars, also known as Banded Woolly Bears, Fuzzy Bears, or Woolly Worms, are the larval stage of Isabella Tiger Moths. Their appearance is quite recognizable! They have brown setae in their mid-regions and black setae in the front and back of their bodies, giving them an overall adorable fuzzy look. Although they have a super cute vibe, handling these caterpillars is discouraged since their spiny setae can cause skin irritation in some people.

These caterpillars have long been thought of as predictors of the coming winter weather. In fact, much of folklore is centered around reading the proportions and variations of the different coloured setae on their bodies!

On your next Fall visit to High Park, keep a careful eye out for Woolly Bear caterpillars wandering by your feet!

FUN FACT: When picked up or disturbed, Woolly Bear caterpillars will curl themselves up into a tight bristly ball and “play dead.”