Tuesday, July 26, 2011

Raising caterpillars.

Earlier this week, my boy was out tending his garden and he came running in to show me the tiny caterpillar he had found.

This interesting little guy was only about 1/4" long. i'm quite amazed that my boy was able to spot it. He said it was just hanging out in the grass, near some Queen Anne's lace. We checked all around the Queen Anne's Lace but found no other caterpillars.

The caterpillar is a Black Swallowtail. This is the first instar. The instars are the stages between shedding skin. It will shed it's skin several times as it grows larger. Host plants for the Black swallowtail caterpillars are Queen Anne's lace, carrot, parsley, fennel and dill. We planted all of these this year, in hopes of attracting the Black swallowtails.

We moved our caterpillar to the carrots growing in the kids garden, where he would be a bit more protected. We were gone over the weekend, and missed getting pictures of the second instar. Here it is in the third instar, it is about 1" long. We will leave him to feed on the carrots until he is full grown and then we'll bring it inside so that we can watch it pupate and transform into a chrysalis.

While weeding the tomatoes, i noticed some rather large piles of bug poo on the leaves and around the base of one of my plants. i looked all over the plant and found the culprit.

This is a huge tomato hornworm. They are considered garden pests, because one caterpillar can do some serious damage to tomato plants. They eat non-stop and will consume not only the foliage but the green tomatoes as well. They are very easy to control. You just pick them off and move them away from your garden. In the past i have just thrown them to the chickens, who tend to follow me around when ever i am in the garden.

This time however, Sage freaked out and wanted to keep it as a pet. :)

It really is rather cool looking. i love the eye spots all along it's body. This guy is huge, he is around 4" long. Which means he is almost ready to pupate.

Unlike monarchs and swallowtails, the tomato horn worms pupate underground. So when we set up a habitat for him, we placed about 2 inches of soil in the bottom of our container. i planted a small tomato plant in the soil so it had something to munch on. We had lots of tomatoes coming up in our compost, so we won't miss this one. If you don't have any extra plants, you can just give him a few leaves or branches from your tomato plant. Replacing them as necessary.

Our hornworm spent the day munching on this tomato plant. We snapped the lid on the container overnight so he didn't wander away, but is the morning there was no sign of him. So we are assuming it has buried itself in the soil and pupated. In two weeks time, it should emerge as a 5 spotted Hawk Moth. If the caterpillar pupates at the end of summer, early fall it will overwinter in the ground.

We've been checking the milkweed near us, looking for monarch eggs but haven't found any yet. We just spotted our first monarch butterfly last week. So we should be seeing them soon. The county mowers have already come by and cut down about 75% of the milkweed that was growing near the road. It always makes me sad to see this. Milkweed is the only plant that monarch caterpillars will eat, so without it there will be no Monarch butterflies.

You can find a lot of good info on raising different butterflies and moths at this website.
When raising caterpillars it is very important to know what type of caterpillar you have, and what types of host plants the caterpillar will eat. Most caterpillars will only eat very specific host plants, and will die if not provided the correct foods.

Raising caterpillars is always fascinating and educational. It's something we enjoy every summer.

For those wondering, i'll be picking the winner of the ecomom giveaway later today!!! :)


  1. What a fun project! You've inspired me. I think next yr we'll try to plant some specific things and see what kind of caterpillars we can find.

  2. I found a whole bunch of these on a bronze fennell yesterday! Thanks for posting this, you helped me identify what type of butterfly they will be!!