August 31, 2012 in Uncategorized
Last year we planted many Pearly Everlasting in the native plant beds along the shoreline at Memorial Park. This year many of them survived the winter, only to have something else happen to them. The plants emerged this spring but were soon completely covered in silk webs and small caterpillars that completely defoliated the plant. This phenomenon looked much like tent caterpillars on a small, wildflower-sized scale. We also found these caterpillars only on Pearly Everlasting – all other plants were left untouched by this caterpillar. To us, this presented a natural-history mystery that begged some answers.
With a bit of research on our part, and a helpful response (link provided below) to an article on the topic, we discovered that the culprit is the spectacularly colored American Painted Lady butterfly, which we’ve noticed in abundance on the site this year. In that response, Janice Stiefel, who raises butterflies in Door County, says, “the larvae favor the perennial pearly everlasting (Anaphalis margaritacea). Some years there are large populations of American painted ladies. During those times, the plants are covered with hundreds of eggs. There would never be enough leaves for all of them, so many larvae die. To help Mother Nature a tad, I used to be able to buy an extra plant or two from the local nurseries, but they don’t carry them anymore. I asked why. The answer was that people don’t like the plants because they get too ‘buggy’”.
We also learned that we are not to worry about the Pearly Everlasting because the plant is known to re-emerge the following year when the butterfly presumably lays eggs on an alternate host. It seemed that it was an excellent year for this butterfly species on our restoration site. However this year’s growth of pearly everlasting did not sustain the population of caterpillars so many of the caterpillars didn’t make it.
Janice’s full response to the article “Simple Act of Kindness” can be found at the Wild Ones web site. Click here to see it