Antheraea polyphemus

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Polyphemus moth
Antheraea polyphemus, adult
Antheraea polyphemus, adult
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Saturniidae
Genus: Antheraea
Species: A. polyphemus
Binomial name
Antheraea polyphemus
Cramer, 1776

The Polyphemus moth (Antheraea polyphemus) is a member of the Saturniidae family, or giant silk moths. It is a tan colored moth, with an average wingspan of 6 inches (15 cm). The most notable feature of the moth is its large, purplish eyespots on its two hindwings. The eye spots are where it gets its name – from the Greek myth of the Cyclops Polyphemus. The caterpillar of the Polyphemus moth can eat 86,000 times its weight at emergence in a little less than two months.

Contents

[edit] Life cycle

The life cycle of the moth is much like that of any other saturniidae species. It lays flat, light brown eggs on the leaves of a number of host plants, including:

When the eggs hatch small yellow caterpillars emerge. As the caterpillars age, they molt 5 times. Each instar is slightly different, but on their sixth and final instar they become a bright green color with silver spots on their side. They feed heavily on their host plant and can grow up to 3-4 inches long. They then spin cocoons of brown silk, usually wrapped in leaves of the host plant. There are generally two broods throughout the United States, one that hatches in early spring and one that hatches in late summer. The moths eclose and then must pump their wings with fluid (hemolymph) to extend them. The females emit pheromones, which the male can detect through its large, plumose antennae. Males can fly for miles in order to reach a female. After the moths mate, the female spends the majority of the remainder of her life laying eggs, while the male may mate several more times. Adults of this family of moths have vestigial mouths, meaning their mouth parts have been reduced. Because of this, they do not eat and only live as adults for less than one week.

[edit] Sexual dimorphism

Differentiating between sexes of this species is very easy. The most obvious difference is the plumose antennae. Males will have a very bushy antenna while females will have a moderately less bushy antenna. Another difference is that the females will be slightly larger in the abdomen due to carrying eggs. There is a surprising amount of variation within this species. Color patterns can range from a reddish-cinnamon to a dark brown but are almost always a shade of brown.

[edit] Pictures

Polyphemus eggs

1st instar caterpillar. Reared on Post Oak.

1st instar caterpillar. Reared on Post Oak.

Polyphemus caterpillar

Polyphemus moth adult female

Polyphemus moth adult male

Polyphemus moth adult variation

Polyphemus moth adult female

Polyphemus moth adults mating

[edit] Threats

Pests of the moths have become a huge problem. Parasitic insects such as some species of wasps and flies lay their eggs in or on the young caterpillars. The eggs then hatch into larvae which consume the insides of the caterpillars. Once the caterpillars pupate, the larvae themselves pupate, killing the polyphemus pupa. Squirrels have also been known to consume the pupae of polyphemus moths, decreasing the population greatly. Pruning of trees and leaving outdoor lights on at night can also be detrimental to the polyphemus moths. Polyphemus moths are located from coast to coast in the US and are found throughout most of Canada.

[edit] Response to Threats

The Polyphemus Moth uses defence mechanisms, like many other animals do, in order to protect themselves from potential predators. One of the most distinctive defence mechanism, the Polyphemus Moth often uses distraction patterns - which serve to confuse, or simply distract, predators. This method of protection involves the Polyphemus' infamous large eyespots, located on its hindwings. It is these purplish circular eyespots in which the Polyphemus obtained its name (in Greek, Polyphemus represents the mythical figure, Cyclops). Eyespots are also startle patterns, a subform of distraction patterns, used for camouflage via some form of deceptive and blending coloration. Most startle patterns are brightly colored areas on the outer body of animals who are already camouflaged to begin with. Another example of the use of startle patterns is the gray tree frog, with its bright yellow leggings. When it leaps, a flash of bright yellow appears on its hindlegs, usually startling the predator away from its prey. It is strongly believed that the use of distraction patterns is a form of mimicry, meant to misdirect predators by markings on the moths' wings.

[edit] External links

[edit] References

Brands, S. J.. Antheraea polyphemus. Systema Naturae 2000. Retrieved on September 30, 2005.