Often confused with butterflies, moths are winged, mostly nocturnal insects that undergo complete metamorphosis. While DNA analysis suggests that butterflies may have evolved from moths, scientists classify these two kinds of insects separately within the order Lepidoptera. About 165,000 species of moths exist in the world, ranging in size from micromoths to giant silk moths, sphinx moths, and owlet moths. When observing moths, you’re more likely to see larvae (caterpillars) feeding than adults. In fact, some species don’t even have functioning mouthparts in adulthood. In this article, we will talk about what moths eat in different stages.
What do moths larval eat?
After hatching from the egg, a moth caterpillar has only two tasks: to gain enough weight to reach the next stage in its life cycle, and to avoid being devoured by a predator in the process. The caterpillar’s camouflage usually takes care of the second task, but what about the first? Some moths lay their eggs on or near the host plant. For instance, the Pine Sphinx feeds only on pine trees, the Cherry Dagger Moth only on cherry trees, and the Common Oak Moth only on oak trees. By contrast, other species will feed on a variety of trees and plants (oak, willow, cherry, poplar, birch, apple, alder, dandelions, and clover are common hosts), though they may still have a preference for certain ones. They may also eat lichens, organic fabrics, and decaying plant material. Inadequate food supplies will lead some caterpillars to cannibalize each other or to prey on soft-bodied insects, such as aphids. As with any animal, the environment dictates feeding behavior.
A caterpillar’s anatomy facilitates continual feeding. It usually has a cleft upper lip to grab food, and has hooks (or crochets) on its prolegs to stay attached to stems and leaves. As the caterpillar grows, it has to molt, or shed its skin, to make room for the extra mass. Most species go through about five larval stages (called instars). When the caterpillar reaches its maximum size, it will become a pupa. Some moth species pupate in a silken cocoon formed by a curled leaf or in a fibrous one hanging from a branch, while others do so in a hardened case on the ground or in an underground chamber.
What do adult moths eat?
Since adult moths are solely concerned with finding a mate and, if female, laying eggs, they don’t require as much nourishment as they did in their larval form. Adults that are able to feed possess a tube-like tongue called a proboscis and, like butterflies, will engage in “mud-puddling,” where they land near liquids, pumping the fluid through their digestive tract and releasing it from their anus. They generally prefer nectar and other juices such as honeydew (a sugary secretion from aphids), juices of decaying fruit, tree sap, and manure liquids. They are attracted to substances that contain sodium and other minerals, which are important for reproduction. Owlet moths in particular will drink tears, blood, and sweat from birds and mammals.
Non-feeding adults, such as Luna Moths, Io Moths, and Atlas Moths, rely on larval consumption to provide them with the energy necessary for flying.