Of Cabbages and...Cabbage Whites

In a recent post, fellow blogger Jim W. reminded us that even though the Cabbage White butterfly is so common a sight that we usually don’t give it a second thought or look, it is yet a marvelous creature. (Give the pictures a click.)

This morning, as I once again made tracks to the milkweed patch, I was given a special visual treat. Not far from the milkweeds is a large stand of another fascinating plant, the Indian Hemp, a relative of the dogbanes. This morning, that stand was alive with scores—perhaps hundreds—of Cabbage Whites, fluttering from flower to flower and plant to plant, producing a spectacular glittering light show. These butterflies may be common, but this morning they put on a decidedly uncommon display.

Other than being common, what else is there to know about Cabbage Whites? First, they’re not native. They were stowaways on freighters from Europe in the 1860s, landing in Quebec. From there they have become ubiquitous throughout North America—everywhere except the extremely cold north.

Second, as their name suggests, they—that is their larvae—eat cabbage leaves, as well as the leaves of most other members of the cabbage family, that is, the Crucifers (or Brassicas.) That means they are not popular with farmers and gardeners who try to grow those plants for fun and profit.

That’s the way it is with aliens, as we mentioned before in our post on Garlic Mustard. A species introduced into a new area devoid of its natural enemies will exploit the situation and grow out of control, to the detriment of native species and the environment in general. It happens every time. Just look at the Celery Farm Natural Area. As you walk along its paths you will see mostly aliens, at least at the understory level—Japanese Knotweed, Japanese Barberry, Tartarian and Japanese Honeysuckles, Multiflora Rose—and of course, the infamous Garlic Mustard. Not that some of those species aren’t attractive and even beneficial as wildlife food and shelter, but they have certainly crowded out or done other nasty things to many of our native plants.

One success story in battling the invaders has been the introduction of tiny Gallerucella beetles to munch on the leaves of Purple Loosestrife. That biological control has virtually saved the Celery Farm from ecological disaster.

Now let’s see. Garlic Mustard is a member of the same family as cabbage. So why aren’t those Cabbage White caterpillars munching on their leaves? Could it be chemical warfare? More research needed.

In the meantime, let’s at least enjoy the magnificence of insect engineering and beauty—and even a light show like the one I witnessed—as examples of God’s creative handiwork and His power in sustaining His fallen, sin-cursed cosmos. After all, at least in the setting of the Celery Farm, the fluttering Cabbage Whites and their leaf-munching larvae are one of our lesser concerns. (Unless someone more expert in the field knows better—let me know.)