Vapourer Moths that cannot fly and do not eat
Many moths have no mouthparts and females with no wings
Although it is commonly thought that moths are flying insects and that they feed on nectar like butterflies, there are many species in which the adults cannot eat at all because they have no mouthparts, and others in which the females have no wings and it is only the males that can fly.
These moths do all their feeding in the caterpillar stage and the food they ate then has to sustain them through their pupal and adult states. Although this may seem very strange to our ways of thinking, it seems to work very well for many species of moth.
The Vapourer Moth is an unusual common moth
A species such as the Vapourer Moth (Orgyia antiqua ) has females that cannot eat and cannot fly and are basically a bag of eggs. They wait on the cocoon, in which their pupa was, for a male to find them and after mating they lay their eggs on the cocoon and die. The males have brown wings and fly about looking for females.
This species is also unusual because it flies by day. The caterpillars are pretty creatures with coloured tufts of fur and hairy bodies and feed on a variety of trees, bushes and other plants.
It is in the caterpillar stage that the insect must build up enough energy reserves from its food to last it in its adult phase. The closely-related Scarce Vapourer (Orgyia gonostigma ) also has females that are unable to fly.
Gypsy Moth and other moths that do not eat
The Gypsy Moth (Lymantria dispar ) has cream-coloured females that have wings but are unable to fly, and brownish winged males that can. In this species, which has often been a pest of fruit trees, the adults are unable to feed.
In the Winter Moth (Operophtera brumata ) the females have stumps of wings but they are totally useless for flying purposes. In this species the females do crawl about but are otherwise similar to the form of the Vapourer Moth and they wait about for the flying males to find them and mate with them. After mating they lay their eggs on fruit trees and die.
Most species in the large Saturniidae silkmoth family are very colourful and some such as the Atlas Moth (Attacus atlas ) are some of the biggest types of moth in the world. Although most silkmoths can fly all species are unable to eat as adults but must feed up as caterpillars. The adults do not even have digestive systems.
The very well-known Silk Moth (Bombyx mori ), which has caterpillars known as silk worms that feed on Mulberry leaves and that are farmed for their silk, has wings but is unable to fly, and the adults only have rudimentary mouthparts and are unable to eat.
The Silk Moth has become dependent on humans even though most of its individuals have a short life and are killed before they even reach adulthood. The Silk Moth has lost all fear of predators and also is unable to fly and would swiftly die out in the wild.
These moth species that are unable to eat or fly and have short lives that appear to only serve the purpose of reproducing their species. Moths that cannot eat usually live less than a week. There are other insect types that are like this with perhaps the Mayfly being the best-known because after a long life as a larva that lives underwater in rivers and streams, when it finally changes into the adult stage it cannot eat and only lives for a day.