It seems like the gypsy moth caterpillars are finally going away, of course changing into gypsy moths. We have sold more products this year to get rid of gypsy moths and their caterpillars than the last ten years combined, but that pales in comparison to the amount of product that we sell every year  for caterpillars to eat. 

 So every week is a new discovery around my house. This week while mowing the yard I made a new discovery on some milkweed that I didn’t plant, but that has grown right in the middle of a firepit in our backyard. With the weather so warm it is not like we are going to use the firepit any time soon so I left the milkweed alone and this week I found a Monarch caterpillar making a home in it. The monarch caterpillar is easily recognized by its vertical stripes of black, white, and yellow. 

Eggs are laid in spring by the Monarch butterfly singly on any of a number of milkweed (Asclepias) species found throughout the monarch’s range, and the caterpillars feed exclusively on these plants. Monarchs only lay one egg per plant so that the caterpillar will not have competition for food as it grows. We have three milkweeds that grow well in our area: Asclepias syriaca - common milkweed, Asclepias Incarnata - swamp milkweed and Asclepias Tuberosa - butterfly weed. We sell out every year of the swamp milkweed and butterfly weed that we carry in our garden center as butterfly gardening has become almost as popular as putting out a birdfeeder. 

Milkweeds produce acrid milky juices that contain toxic compounds called cardenolides, which are stored in the caterpillar’s body and make the larva and its subsequent stages distasteful to predators. After several molts, the caterpillar attains a length of almost two inches long. The fully grown caterpillar usually leaves its milkweed plant to pupate elsewhere as a pale green, golden-spotted chrysalis. After ten to fourteen days the chrysalis becomes transparent, and the metamorphosed butterfly’s dark body is visible. The adult emerges upside down and spend several hours drying its wings before being able to fly. 

Eastern Tiger Swallowtails are another butterfly that is in abundance in our area. They are similar in size to the monarch with yellow and black wings instead of the orange and black of the monarchs. Swallowtails are seen more often than Monarchs simply because they reproduce quicker than monarchs. Swallowtails will lay multiple eggs on any number of trees, their favorites are ash, birch, wild cherry, tulip tree, sweet bay magnolia and willow. 

Luna Moths, the large green moths seen in the Lunesta commercials, are also very popular, but rarely seen mostly because the trees that they like to lay eggs on are not widely grown. Lunas like walnut, hickory and persimmon the most, but will also use birch and sumac when the others are not present. Luna moth caterpillars are large green caterpillars with yellow spots. They are much more camouflaged compared to the monarch caterpillar as the luna caterpillar doesn’t eat milkweed with the toxic compounds. 

The last caterpillar that I will mention is one that everyone starts to look for in September and that is the Woolly Bear caterpillar. Folklore says the amount of black on the woolly caterpillar is supposedly linked to the severity of the upcoming winter. According to the legend, the longer the woolly bear’s black bands, the more severe the winter will be: longer, colder and snowier. On the flip side, the wider the middle brown band is, the milder the upcoming winter will be. So when you start to see woolly bears this fall you’ll see how bad this winter will be.