DISTRIBUTION:

Eacles imperialis imperialis are found throughout the eastern half of the United States with greater concentrations in Ohio, southern Pennsylvania and New Jersey, and the Virginias. In Canada there are populations in southern Quebec and Ontario, but in the provinces the species is generally replaced by the smaller subspecies Eacles imperialis pini.

FLIGHT TIMES:

In the northern half of its range the single-brooded adults are on the wing from June to August. In New Jersey imperialis imperialis (males and females) usually came in to lights in July. In the South this species flies from April to October.

ECLOSION:

Adults emerge from underground pupae with most eclosions taking place before sunrise.

SCENTING AND MATING

Photo (female) courtesy of Tony Thomas (copyright)

The slightly larger female begins "calling" after midnight by extending a scent gland from her abdomen. Smaller males fly into the wind to pick up the scent and track the stationary female. Males have more purple on the shoulders and on the outer regions of the forewings.

EGGS LARVAE, PUPAE

Eggs are usually deposited singly or in small groups of 2-5 on a number of coniferous and deciduous trees. Incubation lasts from 12 to 14 days (less with warmth) and the larvae emerge as solitary feeders. Under natural conditions larvae would leave the food plant at pupation time and burrow underground to pupate.

Larvae will pupate without soil if placed in the dark in a warm place. Covered five gallon buckets, lined with paper toweling, make good pupation chambers.

The next four larval images are all copyrighted and are used with permission only from Tony Thomas. The parent of these larvae was a female from The Great Dismal Swamp on the border of West Virginia and North Carolina.

The first or second instar larva to the left will quickly move away from one to four siblings to become a solitary feeder on oak, maple, pine, sycamore, Sweet gum, or sassafras, the favorite foods of this species.

Larvae still do not consume much in the second and third instars, and they have also been reported to feed upon various cherries, sumacs, birches, willows, and ash trees

Third and fourth instar larvae become heavy feeders but seldom do damage to the many evergreens (softwoods) upon which they also feed: cedar, fir, (larch/juniper), and pine. The impressive hairs which become prevalent in the last instars are non-urticating. Some larvae of other species have stinging hairs. In most cases the larvae take the green form shown at the end of this section.

Steven Stone also reports elm, hickory, hornbeam, chestnut, and privet as foodplants for this highly polphagous species. The green larval form pictured below is more typical of this species.

Courtesy of John A. Weidhaas, University of Vermont

The dimorphic wing coloration of this species is especially evident in this gynandromorph which flew in to a black light in Pottersville, New Jersey, in early July of 1962. My father and I got into an argument over whether it was a male or female until he realized and explained what we had captured.

Listed below are the primary and alternate food plants listed in Stephen E. Stone's Foodplants of World Saturniidae. It is hoped that this alphabetical listing followed by the common name of the foodplant will prove useful. The list is not exhaustive. Experimenting with closely related foodplants is worthwhile.

Abies grandis Acer negundo Acer pseudoplatanus Acer rubrum Acer saccharinum Acer saccharum Aesculus hippocastanum...... Alnus serrulata Betula alba Betula papyrifera Betula populifolia Bursera tomentosa Carpinus caroliniana Carya Castanea dentata Castanea pumila Castanea sativa Cedrus Chamaecyparis thyoides Cochlospermum vitifolium..... Cornus Crataegus Diospyros accharinum Fagus grandifolia Fagus sylvatica Gleditsia triacanthos Gossypium herbaceum Juglans cinerea Juniperus communis Juniperus virginiana Koelreuteria paniculata..... Larix laricina Ligustrum Lindera benzoin Liquidambar straciflua Myrica cerifera Ostrya virginiana Picea Pinus banksiana Pinus echinata Pinus griffithii Pinus serotina Pinus strobus Pinus taeda Platanus occidentalis.... Platanus orientalis Prunus serotina Prunus virginiana Quercus coccinea Quercus laevis Quercus macrocarpa Quercus palustris Quercus rubra Rhus glabra Rhus laurina Rosa Robinia Salix Sambucus canadensis Sassafras albidum Taxodium distichum Tilia americana Tilia europaea Tilia heterophylla..... Tsuga canadensis Ulmus alata Ulmus americana Ulmus procera Ulmus rubra Ulmus thomasii Viburnum dentatum

Grand fir Box elder/Manitoba maple Sycamore maple Red maple Silver maple Sugar maple European horsechestnut Hazel alder White birch White/paper birch Gray birch Torchwood American hornbeam Hickory American chestnut Allegheny chinquapin Spanish/Sweet chestnut Cedar Atlantic white cedar Rosa amarillo Dogwood Hawthorn Persimmon American beech European beech Honeylocust Levant cotton Butternut Common juniper Eastern red cedar varnish tree Larch/Juniper/Tamarack Privet Spicebush Sweetgum Southern bayberry/Wax myrtle American hop hornbeam Spruce Jack pine Shortleaf pine Himalayan pine Pond pine Eastern white pine Loblolly pine American plane tree Oriental sycamore Wild black cherry Chokecherry Scarlet oak Turkey oak Bur oak PinOak Northern red oak Smooth sumac Laurel sumac Rose Honeylocust Willow American elderberry Sassafras Bald cypress American basswood Common lime White basswood Eastern hemlock Winged elm American elm English elm Slippery elm Rock elm Southern arrowwood