Wonders of the woolly bear caterpillar

Most mornings I have to wake my 13-year-old son, but recently I was reminded of a specific and special morning when I walked into his room six or seven years ago. He was fast asleep, but he had a very silly grin on his face. As I watched, he began to giggle then slap one hand with the other.

He eventually laughed himself awake. Startled to see me, he simply said “flying woolly bears.” Apparently he was dreaming about woolly bears with wings. It made sense as his pet stuffed animal of the month at that point was a woolly bear.

Not too long ago, I thought about that happy memory, which made me realize that I hadn’t seen a single “woolly bear” caterpillar since last year.

More often than not, it is the children that will find and bring indoors this very noticeable caterpillar. I think this is a perfect opportunity to teach kids something about nature, especially in the cooler months when the caterpillar is found curled up in a garage or outdoor crevice as it will quickly come back to “life” if put in sunlight or gentle heat.

Though cute and quite an interesting specimen, unfortunately for gardeners, the woolly bear feeds on many plants including grasses, clover and dandelions. But the good news is that it eats very little in the fall because it has completed its growth cycle.

The insect itself is quite variable in appearance. Sometimes five of the front segments appear black, four of the middle reddish brown and three of the hind segments are black. In others, only four front segments are black, six are reddish and two are black at the end of the body. There are still other variations, so that each individual will tell its own story of color.

There are really 13 segments in this particular caterpillar, not counting the head, but the last two are so joined that the children will probably count only twelve. There is a regular number of tubercles (knob-like bumps) on each side of each segment and from each of these arises a small rosette of hairs. However, these bumps are packed so closely together that children may not be able to see them. While the body may appear as if it’s covered with evenly clipped fur, there are usually a few longer hairs on the rear segment.

There is a pair of true legs on each of the three front segments, called the

thorax (remember, insects always have six legs), and there are four pairs of prolegs, or false legs, that disappear later in the woolly’s life. All of the segments behind the front three belong to a body segment called the abdomen and the prolegs are on the third, fourth, fifth and sixth abdominal segments.

The true legs of this caterpillar have little claws and are as shining as if encased in patent leather, but the prolegs and other appendages on the sides are merely elongations of the insect’s sides that help it hold on to leaves.

The yellow spot on either side of the first segment is a spiracle. This is an opening leading into the air tubes within the body around which the blood flows and is thus purified.

The woolly bear’s head is polished black. Its antennae are two tiny, yellow projections which can easily be seen with the naked eye.

The woolly’s eyes are too small for real sight and because of this it cannot see very far and is thus obligated to “feel” its way wherever it goes. It does this by stretching out the front end of the body and reaching in every direction to observe if there is anything to cling to in the neighborhood.

When you try to seize the woolly bear, it balls up and the hairs are so elastic that it takes great difficulty to handle it. These hairs are a protection from the attacks of birds which are not fond of bristly food. Also, when the caterpillar is safely rolled up, the bird sees only a little bundle of bristles and is likely to leave well enough alone.

Children may be tempted to want to keep one of these creatures as a pet and this can be accommodated only if the caterpillar is kept in a small box outdoors as keeping it indoors in a warm room will be fatal to the woolly and a poor lesson for the children.

Normally the woolly bear does not make its cocoon until April or May. It finds a secluded spot in the fall where it curls up in safety for the winter nap.

When the warm weather comes in the spring, it makes a cocoon by spinning silk about itself. In this silk are woven the hairs, which it sheds easily and the cocoon seems to be made of felt. At this point it’s amazing that such a large caterpillar can spin about itself and squeeze into such a small cocoon. Inside the cocoon is a tiny pupa in which is condensed all that was essential of the caterpillar.

The issuing of the moth from the cocoon—a dramatic representation of metamorphosis—is an interesting lesson for the end of May. The size of the moth that comes from the cocoon seems quite miraculous compared with the size of the caterpillar that went into it.

The moth’s color is dull, grayish, tawny yellow with a few black dots on the wings and sometimes the hind wings are tinted with dull orange. On the middle of the back of the moth’s body there is a row of six black dots and on each side of the body is a similar row. The legs are reddish above tipped with black. The antennae are small and inconspicuous and the moth flies only at night.

The mother moth seeks some plant that will be suitable as food for the soon-to-be little caterpillars and she lays her eggs. This is when they become pests to us gardeners, but still a necessary segment in the circle of life.

There’s an age-old myth says that the larger the dark section of the woolly bear, the longer and harder the winter. But larger than what? And what do all of the stripes on the woolly bear really mean?

Try this one. Count the number of colored segments on the woolly’s body and add six. Subtract six from the resulting number and use this number to count weeks on a calendar. Move forward the appropriate number of weeks and you’ll be within a day of the first day of winter.

Of course this formula is predicated on your finding a woolly bear on November 10, otherwise all bets are off. Keep growing.

Andrew Messinger has been a professional horticulturist for more than 30 years. He divides his time between homes and gardens in Southampton, Westchester and the Catskills. E-mail him at: Andrew@hamptongardener.com. The Hampton Gardener is a registered trademark.