After about nine days (typical of females) or ten days (typical of males), the butterfly emerges. Before this happens, the chrysalis darkens significantly. Tiny orange wings begin to show through the sides. The first signs of darkening happen on the morning of the eighth or ninth day (the day before the butterfly will emerge). The darkness first begins to appear where the legs extend between the wings and on the butterfly's back.
By afternoon, significant wing colors have begun to appear; at this stage, one can already determine the butterfly's gender. In the female (below, left), the black areas of the wing develop before the orange areas, and the black veins between orange sections appear nearly as wide as the orange sections themselves. In contrast, the male (below, right) develops its orange areas before the black areas (or at the same time), and the black veins appear significantly smaller than the orange sections of the wing.
Over a period of several hours (normally overnight), the whole chrysalis (except for the wings) turns black as the butterfly's skin forms. When its development is completed, typically in early- to mid-morning, the chrysalis's transparent skin cracks in the area of the head and legs. The butterfly pushes it open and drops its abdomen down, still clinging with its legs to the empty shell.
When the butterfly first emerges from the chrysalis, it has stubby little wings and a plump body. Fluid from the body is pumped into the wings, expanding them to full size (photo at top of page) in a few minutes. After the wings have fully expanded, the butterfly discharges waste products that have built up during its dormant period; if you raise them indoors, you'll want to protect the surface below the darkened chrysalis by laying a flattened plastic bag directly under the chrysalis, and you may also want to place a piece of paper towel over the plastic to absorb the liquid. A couple of hours later the wings are dry enough for the butterfly to take its first flight, usually a short one to the nearest tree. As a fully grown adult, it is now ready to mate and to spawn a new generation.
Rarely, a butterfly's leg muscles fail to develop properly. Unable to push its way out of the chrysalis, the butterfly remains trapped inside. Later in the day, you may notice it becoming discolored from having discharged reddish-brown waste products inside the chrysalis. Even if you peel away the transparent shell, the butterfly's wings will never expand; everything has to happen exactly on schedule, or it won't happen at all.
Though you may grow impatient waiting for a butterfly to emerge, you should never disturb it inside the chrysalis. Let it emerge on its own time. If you try to rush the process, its wings will not expand.
Download and watch some amazing videos of the butterfly emerging and expanding its wings. These videos are nearly 9 MB and 11 MB, respectively. If you're on a dial-up connection, you may wait a long time for them to download. These videos are Copyright (C)2003 by Clay Ruth. You have my permission to use them in an educational or home environment at no charge. Distribution for profit is expressly forbidden. If you do not agree to these terms, don't download the videos.
There are typically three generations in the United States and two in Canada. By August you can find Monarchs in all stages of development. The last adults emerge in early September, just in time to join the great migration southward for the winter. They overwinter in Mexico and the Caribbean. Only the summer's last generation will survive long enough to return northward in the springtime.
Monarch page | Eggs | Caterpillar | Chrysalis | Clay's Home Page