As you head back up the hill, make sure to stop by the Education Building patio to see the Silk Moths! We raise 2-4 species of moths each year, primarily Cecropia, Promethea, and Polyphemus moths, some of the largest on the continent. The silk cocoons on the bottom of the cages are spun by the fully-grown caterpillars during late summer in tree canopies, where they overwinter. From late May to mid July, the adult moths emerge, mate, and deposit eggs on their preferred host plants. You might have spotted the mesh bags protecting the growing caterpillars around the garden from predators. These moths will rarely cause visible damage to their host plants; their population density is low enough to escape notice.
These beautiful moths illustrate the ecological necessity of native plants— caterpillars have a specific, sometimes narrow range of plants they have evolved to digest. Due to pesticide use and habitat loss, many Lepidopterans (butterflies and moths) are in decline. While gardeners are starting to understand the importance of incorporating flowering plants attractive to bees, caterpillar host plants are frequently overlooked. Planting popular tree hosts like black cherry, maple, and hickory will increase visitation from declining moths and our native birds that rely on them for food.