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Black Swallowtail Caterpillars


I was feeling bad about my front flower garden. It’s a mess of weeds, especially on the end where I expanded the bed around the random dirt mound that’s been there since we moved in. I try to pull the tall, obvious ones from time to time just so it doesn’t look quite so messy. I was pulling out hand fulls of ironweed when I saw something that stopped me in my tracks.

Black Swallowtail Caterpillars in the Garden

The Queen Anne’s lace was decorated with vibrant, practically neon caterpillars. I counted 5 but I’m sure there were more I didn’t see. I went back this morning to show my husband and this little guy had finished up that entire flower head and was on to another in less than 18 hours!


The caterpillars are striped in black and lime green with lemon yellow dots. If you mess with them they expel an orange v-shaped organ called the osmeterium from their forehead area.

Hidden in Plain Sight - Black Swallowtail Caterpillars

The caterpillars are surprisingly hard to see for being so obvious. How many do you see in the picture above? I’ve circled them in the same picture at the bottom, scroll down to see if you found them all!

Queen Anne's Lace - Favored food for Black Swallowtail Caterpillars

They feed on carrot family plants. Our first summer here I found a few on a random dill plant that was growing in the back yard. Black swallowtail caterpillars have serious appetites an could do some serious damage if they found their way into your carrots or dill but if you find them don’t squash them!  Carefully transfer them to some Queen Anne’s Lace and you’ll both be happy.

Black Swallowtail Butterfly

The caterpillars over winter in the chrysalis stage and emerge in the spring. There are several generations a year depending on location, weather and host plants. The adults feed on the flowers of red clover, thistle and milkweed. For more information check out: Butterflies and Moths of North America

Hiding in Plain Sight - Black Swallowtail Caterpillars

Did you find them all?