making friends with late-summer caterpillars

hickory tussock moth caterpillar on canna
ALL TOO OFTEN GARDENERS ARE REVOLTED by the sight of a caterpillar, their immediate instinct to kill, kill, kill these seemingly voracious eaters. But how many besides the tomato hornworm or gypsy moth or Eastern tent caterpillar, for instance, do you really know by name, or can you identify by their favored diet? I’m making friends with some moths-in-the-making who are visiting me right now, happy to share a portion of the fading summer garden with some hairy little beasts in the name of a science lesson. Rather than rush to squish, how about asking who they are?

Lately I have a lot of little fuzzy black and white creatures eating the leaves of my cannas (above), which is what got me started wondering who’s who. Turns out that’s the larval form of a hickory tussock moth, I think, whose usual diet is ash, elm, oak, hickory, maple, willow, and other trees.

Though he looks velvety, look but don’t touch, apparently: The long “lashes” of the hickory tussock moth, Lophocampa caryae, are hollow tubes connected to poison glands, and can give susceptible people a stinging nettle-like rash or other reaction. The rest of the bristles, or setae, may also be irritating.

This extensive University of Wisconsin-Milwaukee article offers a full portrait of the life of the hickory tussock moth, which apparently will spend the winter in a silk cocoon under tree bark or on the ground, then eventually works its way gradually next year to moth-hood.

virginian tiger moth
He’s the cousin of two other recent arrivals: a small yellowish-tan caterpillar that I think might be the Virginian tiger moth, Spilosoma virginica (above), which apparently feeds on both herbaceous and woody plants. I found this guy in my house, actually, on a piece of garden gear I’d brought inside, and relocated him to the canna leaf.  He had apparently been parasitized by some wasp or other—you can see the one egg on his rear right side that didn’t fall off when I moved him back outdoors.

nest-with-woolly-bear
Both are cousins of the familiar woolly bear or wooly worm; all three are in the taxonomic tribe Arctiini (the tiger moths). Since they’re not deforesting the entire region or anything, I’m just letting them be–and eat. We just don’t understand enough about all of nature’s tiniest creatures to go blindly rampaging against them, do we?

At this time of year, many of us start to notice the woolly bear, or Isabella tiger moth, Pyrrharctia isabella (above)—looking to see how much black versus rusty banding circles its fat, fuzzy body to try to predict the coming winter. More brown=milder; more black=more fierce, or so the idea goes. As a forecasting tool, it probably doesn’t hold up to strict science by any means, as you can read about on the Farmer’s Almanac site or Bug Guide [dot net], my hands-down favorite online resource for identifying insects, spiders and their relatives of the U.S. and Canada.

Me? I’m forecasting an early onset to winter based on equally folkloric notions, like the fact that three species of feeder birds who usually don’t bother with me again until fall properly sets in—the chickadees, nuthatches and titmice—are already hanging around looking for a meal the last week.

All efforts to ask them what’s up were met with the usual chatter, but nothing I could decode.

20 comments
August 25, 2011

comments

  1. says

    I raise caterpillars; they can be fascinating to watch! I have to bring inside any that I want to see through the whole process – we have a very aggressive Wasp Patrol, which eats all the ones on the plants they can reach.

    • says

      Hi, Michael. Fascinating! As mentioned, one was planning to shack up with me here until I discovered him and set him free. Not sure I want too many of them in the house…. :)

  2. Ginger Goolsby says

    Very interesting post and I thoroughly enjoyed it – pictures are great. Yes, we have had a few days in East Tennessee that have made me think that Fall is just around the corner here also.

  3. says

    Great post. I almost got too squish happy this year when at first I thought a black swallowtail caterpillar was a tomato hornworm as he was hanging out on my tomatoes. I put him over to snack with the carrots….they tasted awful this year anyways.

    Oh and I never like the sound of early onset of winter….hope that only means early onset of Spring next year.

    • says

      I had very few monarchs here as well this year, Honey. Last year monarchs were placed on the World Wildlife Fund’s “watchlist” of top 10 species needing a close eye kept on them because of pressures on habitat and other factors. More about them and their plight (with good links to other sites) is also here.

  4. gretchen says

    very cute but be careful! about 30 years ago, there was an infestation in the houston, texas area of something that looked very much like the hickory tussock moth caterpillar. our then 18 month old daughter reached out and touched it. within seconds she was screaming in pain and within minutes her entire arm had swollen. we gave her anithistamines and iced her arm and she recovered. several people ended up in the hospital and one unfortunate utility worker came in contact with several of the caterpillars and died from the allergic reaction. who knew that something that looked so ‘petable’ could be so dangerous? we certainly didn’t!

  5. Deborah says

    I’ve seen several of the tussock moth catepillars this past 6 weeks or so, starting with a small swarm of them on a twig of my pinxter azalea. I confess I followed a take-no-hostages approach. I didn’t know what they were until in a pruning class in early August, they were identified as such by the co-op extension teacher. He also said to be careful about touching any catepillar that has a few long hairs sticking up, because they may be barbs that contain a poison that stings. I know my chickens wouldn’t eat the ones from my azalea, so I guess they knew more than me about the danger.

  6. Rita Mortenson says

    I love caterpillars. I raise them into butterflies or moths and release them. Only about 1 out of 100 make it to adults in nature, so I like to give them a little boost. But mostly, It’s just so much fun. The tussock moths have some of the cutest ‘pllars! It’s easy enough to raise Black Swallowtail butterflies from the eggs on dill, fennel or parsley; Monarchs lay their eggs on plants in the milkweed family. Oh, and the amazing little caterpillars that make their way on the thorny thistles become beautiful Painted Ladies. Willows feed the Monarch lookalike, the Viceroy; and we’ve raised Red Admirals from eggs found on Snapdragons. Each butterfly or moth has its specific food plant, and with the internet it’s easy for match each winged creature with the plant where you will find its eggs. I started so long ago that I had to use a book! ^__^

  7. Kim Irene says

    About two weeks ago while weeding, I unknowingly, touched a hairy caterpillar. I only knew that because suddenly my fingers were afire with that stinging, nettle like feeling. I looked down and there he was but was different that those you have pictured here. I let him be and went inside and washed my hands. It soon went away but was quite painful for those few minutes.

    I am enjoying your current book, Margaret. I think we may have the same white, enamel trash bin from the MSL now defunct store. You are inspiring for many reasons so keep it up !

  8. Alison Ash says

    Margaret: I was very happy to see your photo of the black and white caterpillar. I have been watching them the last couple of weeks in my garden in Berkshire County. I was afraid they were “late” and would freeze when it gets cold, so I was relieved to learn from your post that they will overwinter in a cocoon. I looked at one up really close and noticed that their markings give the appearance that they have a “face” with two eyes on the front. In reference to Andre’s drawing, we had swarms of (I guess) bumblebees all over a big stand of lavender every single day for weeks. They would come as soon as the sun was up high enough to warm the yard and would leave only at the end of the day. I loved to sit on a step near the lavender and just watch them for long periods. So industrious . . . so cute. I learn a lot from your website . . . thanks. Alison

    • says

      Hi, Alison. I want to take more time to really investigate all the creatures here rather than just react negatively, so these were fascinating to learn about. Say hello to yours from their cousins over here at my place. ;)

  9. Sharon says

    I, too, have been forecasting an early winter.

    I have been judging by the breath of cold I feel on the breeze even when the days are 80 degrees here in Central NJ. Some Canada geese were already winging it south as early as last week. My ornamental cherry has a few leaves turning, another tree down the block is already half red.

    Grey titmice have been hanging around for a while, in fact, I don’t recall that they ever left.

  10. Jacquelyn says

    Here in southern RI, I spent this lovely post hurricane Irene early evening watching among other bird activity, the chick-a-dees, and titmice go back and forth from feeder, to waiting station, to birdbaths, to shrubs for about 2 hours!

  11. Debra Patterson says

    How true! I saw several strange caterpillars in the gadren and my first instinct was to “smoosh away” and then I remembered reading about similar looking carterpillars last year. I rushed in the house and found photographs in the article I has read on the Monarch butterly caterpillar. Strange how quickly my attitude changed!

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