Spring is Calling and I Think of Caterpillars

By Linda Ray

Snowberry clearwing caterpillar

Springtime is coming and the overwintering pupa of the order Lepidoptera, hidden in soil, plant, and leaf mulch break out as mature adults to eat and reproduce. These moths and butterflies seek out their specific host plants where they lay their eggs. The order Lepidoptera, which includes moths and butterflies, is the second largest group of the class Insecta and go through the four stages of complete metamorphosis (holometabolous); egg, caterpillar, pupa, and adult. This life cycle can happen several times in a growing season.

About two to three days after butterflies and moths have laid their eggs, a tiny caterpillar is born. It is already on its host plant and starts eating voraciously. During this stage (which lasts six to twelve days), the caterpillars will grow so rapidly that they will shed their exoskeletons up to five times (called instars) before settling into their pupa stage.  

When you see caterpillars in your garden, stop and take a good long look. They walk on their six true legs (and usually five sets of prolegs). They are all manner of color with stripes, spots, furry hair, horns, tails, and hair pencils. Some have doe eyes that make them look impossibly endearing. Caterpillars climb, curl, shake, hold their bodies in impossible ways, and defend themselves. Some even jump. Most importantly, they are a vital part of local food webs by contributing both energy in the form of food and as the prepubescent form of some of nature’s best pollinators. To help identify a caterpillar you discover, the website Discover Life can be helpful. 

American dagger moth

Caterpillars are the primary food that feeds baby birds as well as some amphibians, rodents, bats, and foxes among others. Their exoskeletons are soft, they are nutritious being full of plant fat and protein. They are large insect forms making it a worthwhile pursuit for parent birds who need to feed their babies hundreds of times per day.  Ninety-six percent of terrestrial birds rear their young on insects and caterpillars without which they may not be able to breed. 

The Habitat For All (HFA) garden is a pollinator garden with many plants specifically chosen to attract moths and butterflies. When you are visiting HFA this summer, look for the handwritten signs that describe which plants attract certain moths or butterflies. The website Native Plant Finder ranks plant species by their ability to host caterpillars and so assists in identifying plants for that purpose. 

In our own backyards, choosing host plants and allowing native wild flowers to flourish almost always attracts a variety of all pollinators.  An overgrown landscape that has an understory with a varied layering of plants and brush, decaying logs, and leaf mulch (for safe pupation sites) promotes diversity and life. Gardeners can have the butterflies and moths they love and contribute to the health of our food web which is the web of life. 

Many caterpillars have hosts plants they prefer

Sources:

Entomology for the Naturalist. Clemson Cooperative Extension 

Tallamy, Douglas W., 2019, Nature’s Best Hope: A New Approach to Conservation That Starts in Your Yard. Portland, Oregon: Tinder Press

McGavin, George C., 2002, Insects: Spiders and Other Terrestrial Arthropods. New York, New York: Dorling Kindersley Limited