A little caterpillar anatomy

By DAY 7, the little guys aren't so little anymore...

Day 7.JPGGeorge day 7.JPG

Now that we can see some details on these guys, let's learn a little about what we're looking at.


Painted lady caterpillars have three pair of true legs, located closest to the mandible. The remaining five pair are called pro-legs or false legs. Although these 'false legs' are functional and important for the caterpillar for feeding, they get the diss because they are lost during metamorphosis. The butterfly emerges with only three pair of legs.

Each caterpillar has six pair of ocelli, or eyes. Even with all these eyes, their vision is very poor. The structure of the ocelli suggests that caterpillars can not see images, only degrees light and dark. These caterpillars also have chemical detectors for taste and antennae for smell.

The spinneret is the opening of the silk gland, which produces the silk disc to which the chrysalis will attach. The spiracles are pretty cool. More on those later.

A few interesting caterpillar facts:
* Unlike most growing organisms, the number of cells composing the caterpillar body does not increase as the caterpillar grows from newly hatched larva to large caterpillar ready to pupate.

* This is especially impressive when you realize a caterpillar grows to approximately 27,000 times its size from hatchling to pupa. This would be equivalent to a 9 pound human baby growing to 243,000 pounds as an adult. Talk about an obesity crisis!

* Caterpillars have upwards of 4,000 muscles. This doesn't necessarily impress until you remember humans only have 640.

* This terror-inducing rug on a branch is called a woolly slug. It's the most poisonous caterpillar in the United States.


"I'm too sexy for my hair."

That's it for now, but let's check back in on the crew...
day 8.jpg

Looks like someone is ready!

More time-lapse coolness:

More like this

Since we last checked in, all 5 of our caterpillars made their transformation to chrysalis! Unfortunately, one of the Georges settled in too close to the side of the container. As he began to pupate, the forming chrysalis touched the plastic side, which must have been enough to cause a small tear…
The transformation from caterpillar to butterfly or moth is one of the most beguiling in the animal world. Both larva and adult are just stages in the life of a single animal, but are nonetheless completely separated in appearance, habitat and behaviour. The imagery associated with such change is…
Younger offspring: (brandishing a decorated and labeled paper plate) You're going to blog about this on Friday. Dr. Free-Ride: I am? Younger offspring: Yes! It has to do with science, and I made it. Dr. Free-Ride: (pretending to think it over) Well, I don't know ... Younger offspring: And this way…
When you lose your job, you find yourself taking on new hobbies and projects. Some of them are productive. Some are fun. And some just satisfy the kid in you. So, say hello to my painted lady caterpillars! These cuties will be spending the next three weeks of their lives with me before being…