The caterpillars eat the leaves of apples, cherries, oak, maple, grape, willow and more. According to Wikipedia , a caterpillar consumes 86, times its original weight in leaves during the two months between hatching and pupation.
Their cocoon incorporates a leaf of their host tree, sometimes attached solidly to a twig, and sometimes dangling and eventually falling to the ground to rest in the leaf litter. Squirrels can be serious predators of Polyphemus caterpillars. Promethia moths Callosamia promethea are found in woodlands from the Atlantic to the Great Plains. The caterpillars bear a family resemblance to Cecropias but lack the row of paired, plain yellow knobs and also eat lilac and forest trees like ash, cherry, basswood, birch and maple, although populations may become food specialists, regionally.
Adult male and female Promethea moths exhibit strong sexual dimorphism — the male is dark brown and the female is reddish and can be mistaken for a small Cecropia. What an improbable moth! What an improbable moth for our less-than-tropical landscape! Go figure. The bizarre reddish caterpillar in the netting is the normally-chartreuse caterpillar of the exquisite Luna Moth. It was captured halfway between the hickory tree whose leaves it probably nibbled they like birch, alder, and sumac, too , and a thicket where it intended to pupate.
Some caterpillars undergo a color change when they have finished eating and are about to pupate; this one had a death-grip on the netting and was minutes away from pupating. Godzilla's fearsome foe? Yeesh, I guess I am getting old. A giant silk moth around here is about the size of the palm of your hand. The biggest moth in the world is the size of two hands. But compared to most butterflies and moths, the silk moths are giants!
They are also some of the most spectacular insects you will ever see. No, that's not an ancient incantation, that's the holy grail of Manitoba's silk moths, the big 4!
There's the Polyphemus moth Antheraea polyphemus , the Luna Actias luna , the Columbia silk moth Hyalophora columbia and the Cecropia Hyalophora cecropia. Of these, the former two are very common and wide-spread throughout forested parts of southern and central Manitoba, while the latter two are found mainly in the southern part of the province and are down-right uncommon.
All are greatly prized by lepidopterists for their size and great beauty. If there's anybody up north who knows how far up the Luna and Polyphemus can be found, please let us know! The distribution of these two moths is not well known! Giant silk moths Family: Saturniidae, Subfamily: Saturniinae, with 10 species in Canada and the United States draw their collective name from the fine silk they use to spin their cocoons which serve as protection for the pupal stage in their life cycle.
The commercial "silkworm" moth Bombyx mori is from a different family Bombycidae. A "real" silk moth. The life cycle of a giant silk moth is pretty simple: hatch, eat, grow, pupate, emerge, mate, lay eggs, die; all in the span of one year. In late spring and early summer adult silk moths emerge from the cocoons where they have spent winter.
In southern Manitoba the main emergence is usually sometime from mid-May to mid-June, later as you venture further north. Further south, in the central and southern United States, silk moths may squeeze two life cycles into one year. There is usually one period, several days to one week, within the late spring when most of the adults will emerge, though there will always be early-birds and stragglers.
This synchrony is important in ensuring that males and females can find each other for mating. The first real warm spell of the year, when temperatures reach into the 20's C and nights stay warm for several days can trigger the main moth emergence.
Adults emerge from their cocoons in daytime, usually around mid-morning. This means they have the warmth of the day to inflate and dry their wings in preparation for the evening's flight. When darkness falls the moths begin their sole function: reproduction. Adult silk moths have no working mouth parts.
They do not feed or drink and will only live for one to two weeks after emerging from their cocoons. Male moths seek out the females by scent.
Females emit strong pheromones chemical scents that trigger behaviours and wait for the males to find them. The plumelike antennae are usually larger in males than in females. Females attract males by releasing pheromones chemical substances whose odors attract males of the species. Males are highly sensitive to pheromones and can be drawn to a female from several miles away.
Females generally release pheromones at specific times during the day or night depending on the species and are usually released for short periods of time 2—3 hours for most species.
Pheromones are used by many other moths and butterflies, but its role with saturniid moths is especially well documented. Whether these are deposited singly or in groups depends on the species. Some saturniid species such as the luna and cecropia moths pupate inside silken cocoons, while others such as the royal moth work their way into the soil and pupate there. Luna moths form a cocoon in leaf litter on the ground, and cecropias form cocoons attached to a twig by silk, while polyphemus moths use silk to wrap a leaf around a cocoon that falls to the ground in autumn.
All Missouri saturniid species overwinter in the pupal stage. The cecropia, for example, has only one brood, but because adult moths emerge at different times between April and June, you may see them throughout that period. People who collect butterflies and moths consider these breathtakingly beautiful moths some of their prized specimens. The large caterpillars in this group can be spectacular as well. An example is the hickory horned devil, which is the larva of the royal walnut moth — it has two names, one for the enormous caterpillar and one for the adult moth.
The family name, Saturniidae, is from the genus name Saturnia. That name references the Roman goddess Juno Hera was her Greek name ; the wife of Jupiter Zeus , she was the queen of the gods. Because she was the daughter of the god Saturn Cronus , she was also called Saturnia. The scientist who first described the genus Saturnia and bestowed the name was the German botanist and entomologist Franz Paula von Schrank. In the early s when he worked, higher education in western universities always included plenty of Latin and Greek history, language, and culture.
Schrank, by the way, was also a Roman Catholic priest. The caterpillars of some saturniid moths are infamous tree pests. The rosy maple moth, for example, periodically has outbreaks that can sometimes completely defoliate soft maple trees.
Generally, and over the long term, these caterpillars do not cause serious harm to their tree hosts. Moths, in all stages of life, are food for many kinds of predators. The forewings of many saturniids provide them camouflage against the leaves and trunks they commonly perch on. The hindwings of several such as the polyphemus and io have large, conspicuous eyespots, which the moth, when disturbed, will reveal by sliding its forewings sideways.
The sudden, startling sight of owl-like eyes may make a predator hesitate long enough for the moth to fly away to safety. The stinging or irritating hairs or spines on the caterpillars of many species is a reminder that these large, juicy larvae would otherwise be choice morsels for many kinds of predators.
Doubtless many predators — owls, perhaps, and snakes — are unfazed by the noxious hairs and spines. There are several other defense mechanisms among members of this family. The caterpillars of some make clicking noises and vomit to deter predators. The tails on the hindwings of luna moths apparently disrupt the sonar that hunting bats use to locate the moths.
Populations of our native saturniid moths are shrinking as an unanticipated result of fly and wasp parasites intentionally introduced to North America to prey on nonnative, invasive gypsy moths. Unfortunately, those parasitoids also attack several of our native saturniids, including cecropia, luna, and promethea moths, reducing their populations in New England and elsewhere.
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