The answer to whether moths consume flowers depends entirely on the moth’s life stage. Adult moths generally lack the physical structures required to chew and ingest solid plant material. It is the larval form, the caterpillar, that is equipped to eat flowers and other plant parts, often causing noticeable damage in gardens. This biological distinction in diet is a result of the insect’s complete metamorphosis.
How Adult Moths Interact with Flowers
Adult moths primarily interact with flowers to obtain energy for flight and reproduction, not for structural consumption. These insects feed on liquid nectar, which they access using a specialized mouthpart called a proboscis.
The proboscis is a long, flexible tube that remains coiled beneath the head when not in use. When feeding, the moth unrolls this proboscis, inserting it deep into the flower’s corolla to siphon the sugary fluid. This action is more akin to drinking through a straw than eating.
The adult moth’s diet is entirely liquid, consisting of flower nectar, tree sap, or liquids from decaying fruit. This feeding behavior makes many moths important pollinators, a process known as phalaenophily, especially for plants that bloom at night.
Hawk moths, also known as sphinx moths, are a prominent example, often hovering in front of flowers similar to hummingbirds. As they feed, pollen inadvertently clings to their bodies and is carried to the next blossom, facilitating the plant’s reproduction.
The Larval Stage: When Moths Really Eat Flowers
The true flower-eaters in the moth life cycle are the larvae, commonly known as caterpillars. Unlike the adult’s siphoning proboscis, the caterpillar possesses powerful, hardened chewing mouthparts called mandibles. These mandibles allow the larva to consume dense plant tissues, including leaves, stems, buds, and the petals and ovaries of flowers.
This larval stage is dedicated almost entirely to feeding and growth, requiring a massive intake of solid plant matter to fuel the moth’s transformation. Certain species are agricultural pests because of their diet. For example, the tomato hornworm, the larva of a sphinx moth, is known to devour leaves and sometimes flowers of nightshade family plants.
Other common garden pests are also moth larvae, such as cutworms, which are known to sever young plant stems and buds at the soil line, or budworms, which bore directly into flower buds and new growth. The damage from caterpillars is distinct, often presenting as irregular holes chewed through petals or entire blossoms completely defoliated.
Identifying Moth-Friendly Flowers
Gardeners can specifically attract adult moths by planting flowers that have co-evolved to appeal to their unique sensory requirements. Because many pollinating moths are nocturnal, they rely on scent and color to locate their food source in low light. The flowers that attract them possess distinct characteristics that reflect these needs.
Moth-pollinated flowers are typically pale or white, making them highly visible against a dark background by reflecting moonlight. They release a powerful, sweet fragrance, particularly as dusk approaches, to guide the moths to the nectar source. Examples of these plants include Nicotiana (Flowering Tobacco) and evening primrose (Oenothera).
These blossoms often have a deep, narrow corolla, which perfectly accommodates the adult moth’s long proboscis while protecting the nectar from less specialized insects. Planting a collection of these night-blooming, heavily scented flowers can create a “moon garden,” providing a functional food source for these pollinators.