Peppered moth
The peppered moth, belonging to the family Geometridae and the genus Biston, is a species found throughout the northern hemisphere. Known for its distinctive coloration, the moth typically has a white or ash-gray body adorned with black markings, which provide effective camouflage against lichen-covered tree trunks. In polluted areas, a darker variant, known as the melanic form, appears to blend into soot-blackened surfaces. The moth's coloring is an example of how certain species adapt to their environments for survival; each moth is born with a specific color pattern that aligns with its habitat.
Measuring approximately 1.5 to 2.5 inches in length, the peppered moth is primarily nocturnal and feeds on tree bark, leaves, and other plant materials. Mating occurs when males detect pheromones released by females, leading to the female laying over 2,000 eggs. The lifecycle involves several stages, including a caterpillar phase and pupation, before emerging as an adult moth. With a lifespan of around eight to nine months, the peppered moth is common in various regions, including Europe, parts of Asia, and North America, and is not considered a threatened species.
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Peppered moth
The peppered moth can be found throughout the northern hemisphere. The peppered moth is named for the black markings which cover its white body. These colors camouflage the moth against lichens on tree trunks. Sometimes this moth is dark brown or black to camouflage itself against dark trees in polluted areas.
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Geometridae
Genus: Biston
Species: Betularia
The peppered moth is a good example of camouflage helping an animal to survive. This species of moth may have one of two different color patterns. The moth is not like a chameleon which changes its colors, but each moth has one color pattern or the other depending on where it is born and lives.
In general, a peppered moth has a pale, white or ash-gray body which is probably around 1 1/2 to 2/1/2 inches (four to 6 1/3 centimeters) long. Dark bands cross its thorax, or mid-body section, and abdomen, or tail section. Its two hind wings are slightly smaller than the forewings, which are up to two inches (five centimeters) from tip to tip. Dark brown or black speckles cover the wings and look as if pepper had been sprinkled over them. These colors and patterns protect the moth from predators, such as birds, since the moth blends with the lichens on the tree trunks. From the small head of the male extend two long, feathery antennae, and the female has two thread-like antennae. The two pairs of wings and three pairs of legs attach to the moth's thorax.
Sometimes the peppered moth's body is completely dark brown or black without any markings. This is called the melanic form of the moth. Colors in animals, plants, and people are the result of colored substances in the cells called pigments. Melanin is the dark-colored pigment which comes to the surface of the skin when people have suntans. Melanin also is the reason for the dark body of the melanic peppered moth. The melanic moth occurs in areas where lots of pollution covers the trunks of trees with soot. The peppered moth camouflages itself from predators on the bark of these trees. The melanic and pale peppered moth are alike except for their colors.
The pale peppered moth inhabits forest and woodland habitats, while the melanic peppered moth lives on trees in or near polluted urban areas. Both are common in Europe and parts of western and central Asia, as well as along the northernmost tip of Africa. They can also be found throughout North America.
Nighttime is when the peppered moth is mainly active. The adult moth lives alone. It is an herbivore, eating mainly tree bark and shrubs but also fruit, nector leaves, flowers, and seeds. The peppered moth flies about looking for a mate since it has only eight to nine months to live. The male moth uses his sensitive antennae to detect the special chemical messages sent by the female. These chemicals are called pheromones and attract the male to the female so the two may mate.
After mating, the female lays her over 2,000 eggs in bead-like strings on the leaves of trees, such as oak or beech. She may lay her eggs anytime during the months of May and June, and the eggs may hatch during June and July. Hatching usually occurs 10 to 14 days after the female lays them. The larvae, or young, are caterpillars. They grow through several stages called instars. In each instar the caterpillar outgrows its body and sheds it so it can grow into a new, larger body. The caterpillar eats the leaves of oak, elm, birch, willow, and plum trees, as well as others. Between September and May each caterpillar rests in the ground inside a brown cocoon. During this time it changes into an adult moth. It is called a pupa, and this process is called pupation. The adult moth emerges in May.
The main predators of the peppered moth include bats and other birds like robins. The life span of the peppered moth is around eight to nine months. They are not a threatened species.
Bibliography
Lemus, Alan. “Peppered Moth Insect Facts - Biston Betularia.” A-Z Animals, 9 July 2022, a-z-animals.com/animals/peppered-moth. Accessed 7 Apr. 2024.
“Peppered Moth.” Butterfly Conservation, butterfly-conservation.org/moths/peppered-moth. Accessed 7 Apr. 2024.