in Thoreau’s Journal:
Under the Salix nigra var. falcata, [black willow] near that handsomest one, which now is full of scythe-shaped leaves, the larger six inches long by seven eighths wide, with remarkably broad lunar leafy appendages or stipules at their base, I found a remarkable moth lying flat on the still water as if asleep (they appear to sleep during the day), as large as the smaller birds. Five and a half inches in alar extent and about three inches long, something like the smaller figure in one position of the wings (with a remarkably narrow lunar-cut tail), of a sea-green color, with four conspicuous spots whitish within, then a red line, then yellowish border below or toward the tail, but brown, brown orange, and black above, toward head; a very robust body, covered with a kind of downy plumage, an inch and a quarter long by five eighths thick.
The sight affected me as tropical, and I suppose it is the northern verge of some species. It suggests into what productions Nature would run if all the year were a July. By night it is active, for, though I thought it dying at first, it made a great noise in its prison, a cigar-box, at night. When the day returns, it apparently drops wherever it may be, even into the water, and dozes till evening again. Is it called the emperor moth? [It’s a luna moth]