Moths of the Limberlost: A Book About Limberlost Cabin

by Gene Stratton-Porter

The Cecropia is a moth whose acquaintance nature-loving city people can cultivate. In December of 1906, on a tree, maple I think, near No. 2230 North Delaware Street, Indianapolis, I found four cocoons of this moth, and on the next tree, save one, another. Then I began watching, and in the coming days I counted them by the hundred through the city. Several bushels of these cocoons could have been clipped in Indianapolis alone, and there is no reason why any other city that has maple, elm, catalpa, and other shade trees would not have as many; so that any one who would like can find them easily.

Cecropia cocoons bewilder a beginner by their difference in shape. You cannot determine the sex of the moth by the size of the cocoon. In the case of the twins, the cocoon of the female was the larger; but I have known male and female alike to emerge from large or small. You are fairly sure of selecting a pair if you depend upon weight. The females are heavier than the males, because they emerge with quantities of eggs ready to deposit as soon as they have mated. If any one wants to winter a pair of moths, they are reasonably sure of doing so by selecting the heaviest and lightest cocoons they can find.

In the selection of cocoons, hold them to the ear, and with a quick motion reverse them end for end. If there is a dull, solid thump, the moth is alive, and will emerge all right. If this thump is lacking, and there is a rattle like a small seed shaking in a dry pod, it means that the caterpillar has gone into the cocoon with one of the tiny parasites that infest these worms, clinging to it, and the pupa has been eaten by the parasite.

In fall and late summer are the best times to find cocoons, as birds tear open many of them in winter; and when weatherbeaten they fade, and do not show the exquisite shadings of silk of those newly spun. When fresh, the colours range from almost white through lightest tans and browns to a genuine red, and there is a silvery effect that is lovely on some of the large, baggy ones, hidden under bridges. Out of doors the moths emerge in middle May or June, but they are earlier in the heat of a house. They are the largest of any species, and exquisitely coloured, the shades being strongest on the upper side of the wings. They differ greatly in size, most males having an average wing sweep of five inches, and a female that emerged in my conservatory from a cocoon that I wintered with particular care had a spread of seven inches, the widest of which I have heard; six and three quarters is a large female. The moth, on appearing, seems all head and abdomen, the wings hanging limp and wet from the shoulders. It at once creeps around until a place where it can hang with the wings down is found, and soon there begins a sort of pumping motion of the body. I imagine this is to start circulation, to exercise parts, and force blood into the wings. They begin to expand, to dry, to take on colour with amazing rapidity, and as soon as they are full size and crisp, the moth commences raising and lowering them slowly, as in flight. If a male, he emerges near ten in the forenoon, and flies at dusk in search of a mate.

As the females are very heavy with eggs, they usually remain where they are. After mating they begin almost at once to deposit their eggs, and do not take flight until they have finished. The eggs are round, having a flat top that becomes slightly depressed as they dry. They are of pearl colour, with a touch of brown, changing to greyish as the tiny caterpillars develop. Their outline can be traced through the shell on which they make their first meal when they emerge. Female Cecropas average about three hundred and fifty eggs each, that they sometimes place singly, and again string in rows, or in captivity pile in heaps. In freedom they deposit the eggs mostly on leaves, sometimes the under, sometimes the upper, sides or dot them on bark, boards or walls. The percentage of loss of eggs and the young is large, for they are nowhere numerous enough to become a pest, as they certainly would if three hundred caterpillars survived to each female moth. The young feed on apple, willow, maple, box-elder, or wild cherry leaves; and grow through a series of feeding periods and moults, during which they rest for a few days, cast the skin and intestinal lining and then feed for another period.

After the females have finished depositing their eggs, they cling to branches, vines or walls a few days, fly aimlessly at night and then pass out without ever having taken food.

Cecropia has several 'Cousins,' Promethea, Angulifera, Gloveri, and Cynthia, that vary slightly in marking and more in colour. All are smaller than Cecropia. The male of Promethea is the darkest moth of the Limberlost. The male of Angulifera is a brownish grey, the female reddish, with warm tan colours on her wing borders. She is very beautiful. The markings on the wings of both are not half-moon shaped, as Cecropia and Gloveri, but are oblong, and largest at the point next the apex of the wing.

Gloveri could not be told from Cecropiain half-tone reproduction by any save a scientist, so similar are the markings, but in colour they are vastly different, and more beautiful. The only living Gloveri I ever secured was almost done with life, and she was so badly battered I could not think of making a picture of her. The wings are a lovely red wine colour, with warm tan borders, and the crescents are white, with a line of tan and then of black. The abdomen is white striped with wine and black.

Cynthia has pale olive green shadings on both male and female. These are imported moths brought here about 1861 in the hope that they would prove valuable in silk culture. They occur mostly where the ailanthus grows.

My heart goes out to Cecropia because it is such a noble, birdlike, big fellow, and since it has decided to be rare with me no longer, all that is necessary is to pick it up, either in caterpillar, cocoon, or moth, at any season of the year, in almost any location. The Cecropia moth resembles the robin among birds; not alone because he is grey with red markings, but also he haunts the same localities. The robin is the bird of the eaves, the back door, the yard and orchard. Cecropia is the moth. My doorstep is not the only one they grace; my friends have found them in like places. Cecropia cocoons are attached to fences, chicken-coops, barns, houses, and all through the orchards of old country places, so that their emergence at bloom time adds to May and June one more beauty, and frequently I speak of them as the Robin Moth.