Grit Blogs > A Lakeside View

Where Oh Where Have My Caterpillars Gone?

By Cindy Murphy


Tags: butterflies, catterpillars,

Each morning, before anyone else is up, I sit on my front porch with my coffee, and watch my yard wake up. Sometimes, sloshing hot coffee, I stroll, taking stock of what’s happening in my gardens.

Look who I found on the swamp milkweed toward the end of July! A monarch butterfly caterpillar; I named him Clyde. Clyde the Caterpillar. What? Naming an insect is strange? But monarchs hold a special place in the annals of my childhood memories.

Clyde

Which came first the monarch or the caterpillar? I can’t remember, but two different monarch encounters left a lasting impression, one involving a caterpillar, and the other the butterflies they become. One summer my brother and I found a monarch caterpillar on a milkweed in the field at the end of the street, and brought it home. My dad built a screen cover to put on an old aquarium, and we kept the caterpillar (I don’t remember its name, but I’m sure it had one), in there along with some milkweed leaves and stalks, and watched it turn into a chrysalis. It hung there, attached to the screen, until the beautiful butterfly emerged before we released it back in the field.

The other childhood memory is of a special place. We were camping up north in September, and my parents took us somewhere other campers mentioned was a sight to behold - a field high on a bluff overlooking Lake Michigan, with a single tree. That tree was covered in monarch butterflies – hundreds, perhaps thousands of them, and even more fluttering through the field. Word was they were gathered there, readying themselves to make the flight south. Just imagining seeing that many butterflies gathered in one place is amazing. Being in the center of the gathering was magical.

Clyde was the first caterpillar I’ve seen on the swamp milkweed, and I’ve waited for him for nearly three years. He’s one of the reasons I planted the milkweed; they are a host plant for monarchs. In their caterpillar state, monarchs eat only milkweed leaves. Like Lori wrote in “Of Parsley and Caterpillars”, I was thrilled with my caterpillar’s arrival. My excitement was short lived however; the following morning, when I went out to wish Clyde a good morning, he was missing!!! He was there just the evening before…and it’s not a large garden; I checked everywhere without any luck.

Oh, where, oh where, did little Clyde go? Maybe a bird ... gasp ... don’t even think it, Cindy. I thought monarchs tasted bad and therefore birds left them alone ... but maybe that’s only in their metamorphed form and doesn't apply to caterpillars.

For days, I search and searched for Clyde ... and found Claudette. She was smaller than Clyde, but just as pretty. I found her a couple mornings later while drinking a cup of coffee, and combing the milkweed again for Clyde. Not that any caterpillar could replace Clyde, but I was happy Claudette came to visit, and I then settled to my spot on the porch to finish my coffee and watch the birds.

Oh, look - there's the little house wren; the busy little bird that darts all over the yard, and hops throughout my gardens. Right now he's in the front garden ... where Clyde was! And Claudette is ... er ... was; I passed by the milkweed on the way to my car less than an hour later, and Claudette was gone too! For weeks afterward, my husband called the little bird The Wren Reaper, and teased me that the monarchs fluttering around the garden were Clyde and Claudette reincarnated. Toward the end, though I found no chrysalis to indicate either of them made it past their caterpillar form, he could have been right. Monarchs have fairly short life cycles, and it was possible they turned into butterflies by that time.

From egg to butterfly, the life span of a monarch is about six to eight weeks. The time spent inside an egg is about 4 days; as a caterpillar it lives for about two weeks before changing into a chrysalis. After ten days inside the chrysalis, it emerges to live as an adult butterfly for approximately two to six more weeks. There are four to five generations of monarchs repeating this life-cycle each summer, but the last generation lives about six to eight months. This is the generation that makes the long migration to hibernation sites in Southern California and Mexico. In February and March they begin to re-awaken, and after mating and laying the eggs of the next generation, they finally die.

Monarchs aren’t an endangered species, but this amazing migration is. Their over-wintering habitats are being lost as more and more land is cleared. During the summer months, food supplies are threatened as herbicides are used on the milkweeds that the caterpillars eat, and some of the other plants that the butterflies use as nectar sources. Insecticides used on mosquitoes and other insects are also killing both monarch caterpillars and butterflies.

If it weren’t for another batch of monarch caterpillars I found, I would have gone on blaming the wren for the disappearance of Clyde and Claudette. In one of the hoop houses at the nursery where we keep perennial re-stock, grew a common milkweed. Though it was rooted between the houses, it escaped the mowers by growing up under the shade cloth, its stalks reaching nearly three feet above the potted perennials surrounding it. A couple of weeks ago, I noticed the familiar white, black and yellow stripes on its leaves, and found not one or two, but five monarch caterpillars on the plant, and another crawling outside of the house, on the shade cloth. I didn’t have my camera, but brought it the following day ... only to discover there were no caterpillars to capture on film. Every last one of them was gone! Frass and chewed leaves were the only evidence that they’d been there.

I decided some investigative work needed to be done, and set out on the Information Super Highway to see if I could determine what was eating my caterpillars. It was just as I had thought: monarchs taste bad. The milkweed the caterpillars eat and store in their bodies even as adult butterflies, contains a toxin. This defense mechanism works so well, that birds that have attempted munching monarch caterpillars and butterflies rarely try the same dish twice. In one study, birds that previously ate monarchs got physically ill and vomited upon even seeing another monarch. So it was doubtful the wren ate both Clyde and Claudette, or that the caterpillars at work were eaten by birds.

There are other predators though, that aren’t bothered by the milkweed toxin. Spiders, wasps, and some other insects, will eat the caterpillars, but this too seemed unlikely to me. There were just too many caterpillars that disappeared in too short a time for me to believe that insects were the culprits.

Cats? They’re a common denominator at home and at work. A big orange one walks down the sidewalk past my house each morning, returning home after a night out on the town, and just recently we noticed a stray at the nursery, prowling the children’s garden…which is close to the hoop houses. Does “erpillar” mean “free food” in feline? Is a caterpillar an advertisement for a feline open buffet? There were no signs of a struggle; no broken stems, disturbed mulch or kitty footprints in my garden, and no overturned pots in the hoop house. I suppose I’ll never know where my caterpillars went.

But this past Sunday, I found this little guy on the same hoop-house milkweed. He’s extra-special – a part of the last generation of the season, and one of those that’ll migrate in a few weeks. I hope he makes it; I hope he’s still around to give it a try.

Hoop House Caterpillar