In their primal phase, moths possess chewing organs that they use to chew just about anything in their proximity. This includes hair, fur, furniture, paper dust, and materials composed of oil and wool.
Apart from the resplendence of butterflies, moths and butterflies are quite similar in their appearance. Both possess two wings, a pair of antennae, and are known to feed on nectar. Scientists claim that butterflies essentially evolved from moths, yet they classify these insects separately in the order Lepidoptera, which translates to “scaly wings”.
However, unlike butterflies, moths are known to be nocturnal insects, which denies them the use of vision to locate food. Moths also have larger antennae than butterflies, which are devoid of knobs. The larger antennae give moths excellent olfactory senses, enabling them to feed on flowers that bloom at night. These flowers radiate an intense smell that is effortlessly picked up by wandering moths.
Unfortunately, moths have acquired a nefarious reputation for ripping holes in our beloved sweaters. That being said, adult moths found reposing on fabrics are highly misunderstood creatures; they are not eating your favorite winter wrap. It’s the larvae of the moth, also called caterpillars, which are the culprits. In fact, some species of adult moths lack the apparatus to chew food at all—they don’t have mouthparts to feed on anything!
Yet, if adult moths seldom eat anything, how do larvae grow into sepia-winged adults? What do they eat?
What do larvae eat?
After a larva spurts into existence, it has only two indispensable aims: to gain weight in order to proceed into the next phase of their life cycle, and throughout its youth, to avoid being killed by a predator.
Gravid adult moth lay several eggs in the vicinity of a host plant. Upon hatching from the egg, the first thing larva begins to eat is the egg shell from which it was born. It then forays into eating host plant leaves. For instance, a Cherry Dagger Moth only feeds on cherry trees, and the Common Oak Moth only feeds on, as you might have guessed, oak trees. Larvae are such voracious eaters that after their birth they keep eating for 5-7 days and continue getting bigger in size. It grows so fast that their skin cannot keep up with its growth, so they shed their skins many times during this phase. This shedding is technically called molting. If several larvae breed unabated, their incessant eating can even cause the death of the host plant.
The diet of the larvae is not limited to just plants or nectar, which are the foods with which they are most often associated. Larval moths are known to be ravenous feeders. In their primal phase, they possess chewing organs that they use to chew just about anything in their proximity. This includes paper dust, hair, fur, furniture, and materials near oil and wool. The contempt we feel for adults is misdirected, as it is actually baby moths—the caterpillars—which are gluttonous eaters.
Do moths eat clothes?
Moths are often called textile pests, but as mentioned, it’s not the moths who eat clothes, but rather the larvae or caterpillars. Besides the usual plants and leaves, larvae are very fond of fibers in clothes. Two species, the case-making clothes moth (Tinea pellionella) and the webbing clothes moth (Tineola biselliell) are famous fabric eaters. Both of these species are known to eat natural cloth fibers found in clothes, curtains, carpets, bedsheet, and upholstery. They can devour wool, cotton, silk, cashmere and lint.
An adult female moth generally lays a few dozen eggs in its lifetime. And if she lays on fabric like fur or cashmere, they are generally attached with a special type of adhesive to hold them to the fabric. These eggs are too small to be seen with the naked eye. Hence, it’s almost impossible to identify a caterpillar infestation until the hatched larvae eat enough to cause holes in the fabric—and by then it might be too late!
To avoid a moth infestation, one of the best remedies is sunbathing and brushing the fabric regularly. Another option is to use mothballs made of a chemical called paradichlorobenzene. Paradichlorobenzene is toxic for larvae and their eggs, as it suffocates the moth and larvae. Vacuuming can also be another alternative to keep larvae infestations in check.
What do pupa eat?
Between the larval and the adult stage is the pupal stage. The pupal stage is also called chrysalis. To avoid being devoured by a predator, the pupa is designed to protect itself by means of camouflage or through its solidity. Otherwise, the moth can undergo its pupal stage by remaining underground. In this stage, moths remain still and do not eat. They simply put to use all the food it chewed up during the larval stage to prepare itself for the next phase of life. Depending on the species, chrysalis may last from a few weeks to a few years!
What do adult moths eat?
There exist at least 150,000 species of moths in the world, including the Giant Moth, Sphinx Moth, and Owlet Moth. After the larvae have accomplished their primary survival tasks, they progress into the pupal stage and finally bloom into the final stage of their ephemeral lives.
A moth’s only aim throughout its adult life is to find a mate and procreate to facilitate the continuation of its species. An adult moth, therefore, does not require as much nourishment as a larval moth.
Feeding through a proboscis
The chewing apparatus is transmuted into a tube-like apparatus called a proboscis. Similar to butterflies, this tube provides a moth with a fluid-pumping mechanism to suck on a flower’s nectar, which then flows into their digestive tract and is excreted through its anus. Adult moths need this nectar fluid to power its wings for flight.
Other than nectar, they also suck on honeydew, juices of decaying fruit, tree sap, and manure liquids, animal droppings or feces. Adult moths generally display a propensity to feed on food that is rich in sodium or minerals that enhance its virility; they are consumed to gain energy for reproductive purposes through such a diet. This is why moths often land on people’s shoulders in the park to lick sodium-rich sweat.
Can moths bite humans?
No, moths do not bite humans because they lose their biting power during chrysalis. As they progress into a full-sized moth, they survive by sucking in liquid juices rich in sodium, sugar and other minerals. However, their feces and cocoons can be harmful. If they become mixed with edible items, such as on the underside of a leaf, it can lead to contamination. Taking in this contaminated food can make us ill. Furthermore, many people experience allergic reactions upon wearing clothes that were previously infested by moths.
Interestingly, some adults do not feed at all! They simply bank on the energy they accrued as a young moth while foraging through the surrounding vegetation. This stored energy is utilized later for flying and reproducing!