In past episodes we visited the meadow to see goldenrod and the horde of pollinators and predators (LINK OCT 3, 2005) associated with this beautiful plant. While providing nectar, pollen, and refuge for many insects, goldenrod is also consumed by several hungry herbivores, none of which are more impressive than cryptic caterpillars known as loopers. While photographing the wedge-shaped beetle (LINK Sept 22, 2008) we met a few weeks ago, I spotted what appeared to be a thin strand of plant material suspended from a branch. Closer observation revealed a greatly elongated green caterpillar moving gracefully from blossom to blossom eating florets along the way. As it moved, it was easy to see why this larva belonged to a group of caterpillars commonly known as loopers. Loopers are members of a large family of moths known as geometrids. The name geometrid derives from Latin roots meaning earth measurer. Another common name for geometrid caterpillars is inchworms, and as loopers and inchworms move along, they do appear to measure the earth an inch at a time.
The green caterpillar in this Bug of the Week is likely the blackberry looper, Chlorochlamys chloroleucaria, based on its appearance and the fact that it was observed in Maryland on goldenrod in autumn. In addition to goldenrod, the blackberry looper eats many plants common to meadows and gardens including blackberry, strawberry, yarrow, zinnia, dogbane, and sweet fern. After feeding for several weeks, the larva will move to the ground and form a cocoon to spend the winter as a pupa. With the return of spring and a new bounty of plants to eat, the pupa completes development and a beautiful emerald green moth emerges. The she-moth lays eggs on nutritious plants and with the appearance of young caterpillars, the cycle of life is complete. After enjoying the antics of the blackberry looper, an unusual movement drew my attention to pieces of dried flowers that were just a bit too active to be parts of a plant. Beneath a cloak of withered goldenrod flowers, a camouflaged looper, Synclora sp., performed a herky-jerky waltz among the flowers. This little trickster gathers pieces of vegetation and arranges them on its back much the same way soldiers incorporate leaves and branches into their camouflaged uniforms to hide from the enemy. The spasmodic movement of the looper added to the illusion of a plant part being blown by the wind. Camouflaged loopers eat many types of flowers including ageratum, aster, black-eyed Susan, boneset, daisy, goldenrod, ragweed, raspberry, rose, sage, St. John’s wort, and yarrow. The adult moth of one species is known as the wavy-lined emerald and it is every bit as beautiful as the larva. Visit your nearest goldenrod patch for one last look at these clever herbivores before they take refuge from late autumn’s chill.
The wonderful reference “Caterpillars of Eastern North America” by David Wagner was used as a reference for this Bug of the Week.