Moths and butterflies are both members of the insect order Lepidoptera, characterized by scale-covered wings and a complex life cycle. Generally, the answer is no: adult moths do not eat butterflies, as their mouthparts and dietary preferences are not suited for predatory behavior. The vast majority of species rely on plant-based liquids or stored energy.
The Primary Diet of Adult Moths
The adult stage of a moth’s life is primarily focused on reproduction, and their feeding apparatus reflects a specialized, non-predatory diet. Most adult moths possess a coiled, tube-like mouthpart called a proboscis, which functions like a straw to draw up liquids. This structure is highly adapted for sipping substances such as flower nectar, tree sap, or the juices from rotting fruit.
The proboscis lacks the mandibles or chewing parts required to consume solid food, including another insect’s body. Many species of moths also seek out sources of water rich in sodium and minerals, often found in animal droppings or mud puddles. Furthermore, some of the largest moths, such as the Atlas, Luna, and Cecropia moths, do not possess functional mouthparts at all. These species survive entirely on the energy reserves accumulated during their larval stage, existing only for a short period to mate and lay eggs.
Dietary Habits of Moth Larvae
The larval stage, commonly known as the caterpillar, is responsible for the bulk of a moth’s lifetime food consumption and energy storage. Unlike the adult, the caterpillar possesses powerful chewing mouthparts called mandibles, which it uses to process solid food. However, the diet of nearly all moth larvae is strictly herbivorous, meaning they feed on various parts of plants, such as leaves, stems, or roots.
Some moth caterpillars are highly specialized, feeding only on a single species of host plant, while others are generalists that consume a wide variety of vegetation. Even with their chewing mouthparts, typical moth caterpillars are not equipped to hunt and consume the tough, chitinous bodies of butterfly larvae or adults. Less than one percent of all Lepidoptera species are considered carnivorous.
Rare Exceptions: Moths With Predatory Needs
While the vast majority of moths are harmless liquid-feeders or plant-eaters, a few specialized species exhibit predatory or parasitic behaviors. These exceptions are extreme outliers and do not represent a threat to butterflies. An example of an unusual adult is the Calyptra genus of moths, sometimes called vampire moths, which use a specialized, barbed proboscis to pierce the skin of mammals and drink blood for salt and mineral intake.
Among the larvae, some Hawaiian species have evolved to become active predators in their isolated ecosystems. The caterpillar of the “bone collector” moth ambushes prey by covering itself in the remains of dead insects as camouflage. Other Hawaiian moth larvae are ambush predators that wait on leaves, striking passing insects with specialized, modified legs. Though these carnivorous caterpillars exist, their prey consists of smaller insects and soft-bodied arthropods, and there is no evidence to suggest they regularly target or consume butterflies.