Finding the Little Things

There are a lot of advantages to being vertically challenged. 

The other day we had a group of children out for programs highlighting plants.  They learned how seeds travel, how seeds store food and energy, and the important role(s) of plants in our ecosystems.  They also learned how to identify some of our more “dangerous plants,” how to make whistles from acorn caps, how to make cordage from plant fibers and how to make toy ducks from cattail leaves.  It was a lot of hands-on fun for all involved.

After showing my first group wood nettles and discussing why it is a good plant to avoid, I had my eyes peeled for poison ivy.  It seems I can never find it when I need it.  I thought I had found a PI vine, and was starting to tell the kids how to recognize it (leaflets three, let it be; hairy rope, don’t be a dope), when I noticed that the vine I was looking at, while indeed sporting three leaflets on each leaf, had a couple suspicious leaves with itty bitty fourth leaflets present.  Hm…

Just as I was contemplating (to myself) these “aberrant growths,” the kids started shouting “there’s a caterpillar, there’s a caterpillar!”  I had no idea what they were talking about – I saw no caterpillar!  But sure enough, underneath the leaf, there was a small green caterpillar.  The kids had seen it because their heads were all beneath the leaf – I was too tall and was looking down at the leaf!  

Pandorus sphinx Eumorpha pandorus on Virginia creeper.JPG

And what a magnificent caterpillar it was:  about an inch long, bright green, with brilliant white spots on its flanks and a wisp of a red horn on its back end.  The front end was held rigidly erect – no doubt trying to look big and tough to scare us off.  Well, we ooo-ed and we ahh-ed, photos were taken, and then we moved on.

Back in the office I looked up our mystery larva, and it turns out it was a Pandorus sphinx, Eumorpha pandorus.  It’s a lovely cream and brown moth, perfectly designed to blend in in its woodland surroundings, and reading up on it I discovered that our caterpillar was doing all the trademark things noted for this species:  a) it was on the underside of a leaf, and b) the leaf it was on one of its food preferences, Virginia creeper (Parthenocissus quinquefolia), as was evident by those rogue fourth leaflets.

The white spots on the caterpillar’s sides each surround one of the caterpillar’s spiracles, or breathing holes.  Why it’s to the caterpillar’s advantage to have its spiracles made so obvious is unknown to me, but an interesting question nonetheless.  And the little red tail/horn is only present on the early and middle instars, so we obviously had a youngster.  On the final instar the horn is replaced with a “button,” which looks a lot like an eye.  Perhaps it, too, serves to scare off predators.

Another interesting thing about these caterpillars is that they come in several colors: pink, green, orange, brown, black or cinnamon.  And they can change color for the last instar.  Why?  Are the colors diet related?  Maybe predicated on the habitat they are in?  Luck of the draw?  I have no idea, and I've not found an answer online yet, but it is sure fun to speculate.

Besides rearing up, displaying the tail horn, or hiding under leaves, what can these stunning caterpillars do to protect themselves?  Apparently they use regurgitation to ward off ants and other parasites that might want to prey on them.  We didn't put that to the test.

So today I tip my hat to the second graders who saw a caterpillar I never would have seen because I was too tall (it’s not often I get to say that) and too focused on identifying a plant.  Because they are curious and closer to the ground, kids often see things that we adults miss…and it can almost always be an eye-opening experience.  I encourage everyone to occasionally change your perspective:  get down on the ground and look at things from the level of a chipmunk; climb a tree to see how the landscape looks to a bird perched on high; take a child out and kneel down at her level to experience nature when you are less than three or four feet tall.  Let us know what you discover.