The Cecropia Moth
(Hyalophora cecropia, Linnaeus, 1758)

Hyalophora cecropia moth image composited by Bill Oehlke

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Superfamily: Bombycoidea, Latreille, 1802
Family: Saturniidae, Boisduval, [1837] 1834
Subfamily: Saturniinae, Boisduval, [1837] 1834
Tribe: Attacini
Genus: Hyalophora Duncan, 1841


Wind Beneath My Wings
copyright C. Odenkirk
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The cecropia moth (Hyalophora cecropia), North America's largest silkmoth with a wingspan approaching six inches, flies in all Canadian provinces except British Columbia and Newfoundland. In the U.S., there are some highly localized populations reported in Washington and Utah, but generally the moth is absent west of mid-Montana, mid-Wyoming, mid-Colorado, and mid-Texas. To the east, is it very abundant in many states.


Like all Hyalophora species, cecropia is univoltine,i.e., there is only one brood each year. Cecropia moths emerge from mid May until early July in the top half of their range, and tend to emerge from March through May in the more southern regions. Bimodal emergences (emergence peaks that occur at distinct periods) are reported in some areas, particularly the midwest, where approximately twenty percent of livestock emerges in late May or early June. The remainder of the stock begins emerging about two weeks later.


Photo by Dan MacKinnon for Bill Oehlke

Cecropia tend to emerge in mid morning from relatively large cocoons and have little trouble slipping through the loose valves in both the inner and outer cocoons.

The adult moths quickly climb to hang and inflate their wings.


Male cecropia have been marked and are known to have flown over seven miles in search of the wind-born female pheromone scent plume. After the couple separates the following evening, males are on the wing again and some males have successfully fertilized as many as three females. Hybridization occurs with other Hyalophora species where distribution areas overlap. Here in the northeast
H. columbia matings occur just before dawn while cecropia are more likely to begin mating from 1:00 am until 3:30 am. Cecropia mate readily in captivity, even in small cages.

Photo courtesy of Mike Soroka.

The striking coloration of the wings is evident in this mating pair. The female to the left has a heavier body and lacks the well developed antennae of the male.
Most Hyalophora species mate in the early morning hours, just before dawn, and remain coupled until the following evening. Some populations, however, tend to mate shortly after dusk.


Large eggs with reddish brown mottling are deposited in short rows of three to six on host food plants. Black first instar caterpillars eat a portion of their eggshells and tend to be gregarious, lining up side by side on the underside of a leaf. Second instar larvae with yellow/green bodies and black protuberances are also gregarious and progress rapidly. Third, fourth, and fifth instar larvae are similar in their spectacular appearance.

Most caterpillars spend approximately one week in each instar (a growth period ended by a shedding of old skin) except the final one of two weeks where a total length of 4.5 inches is often reached.

Large cocoons are always fastened lengthwise to branches, stems, trunks of the host plant or neighboring locations. Sometimes a leaf wrap is used, but often the caterpillar will fashion its cocoon without the aid of any props. A loose valve is spun at the pointed top of the oblong cocoon and another valve is arranged at the top of a denser, inner cocoon.

Click on caterpillar to see a large image and to access a food plant list.

Click notes to access notes on cecropia.

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