Growing up Monarch – 4

“Growing up Monarch” is an on-going segment in the River Bend blog that follows the lives of several monarch butterflies as they grow from egg, to caterpillar, to chrysalis, to adult. We’ll be updating with photos and fun facts and observations throughout the summer!


Time flies—literally—when you’re caring for butterflies. And those caterpillars who were smaller than pencil tips just a month ago are now full-fledged and flying strong. However, this transformation did not occur over night. When last we checked in, (on Monday, May 12th) all three caterpillars had successfully pupated, and all three were safely relocated to larger enclosures for observation. The chrysalises were also studied with a hand lens to determine their gender. This can be a difficult stage to sex monarchs, and it is also the earliest you can sex them without having to kill and dissect them.


Females can be identified in chrysalis by the line intersecting the upper abdominal segment. (Lower image) Males lack this line. (Upper image) Photo credit: Stephanie Rathsack


After looking closely at our three individuals, it was determined that the first (the largest caterpillar) was female, while the other two remaining chrysalises were male. While this will make little difference in the rearing process, it makes for interesting data and will allow for easier planning of potential breeding.


By the afternoon of Monday the 19th, the two older chrysalises had started to darken—revealing the colorful patterns on the butterfly’s wings. Photo credit: Stephanie Rathsack

It takes approximately ten days for the chrysalises to mature to adult butterflies, and during this time period, very little occurs that is visible to the caretaker. The chrysalis will remain green and entirely stationary during the whole length of the 10-14 days, and only in the last twenty-four hours will a noticeable change begin to take place.

Just before emerging, the chrysalis darkens immensely—becoming so transparent that the butterfly and all details of its anatomy and coloration become visible. Photo credit: Stephanie Rathsack


When the chrysalis darkens, everything becomes a waiting game. It takes less than a minute for a stationary (almost dead looking) chrysalis to emerge s a living breathing butterfly. With such a short window of time to watch for, even short lapses in concentration can cause the viewer to miss the opportunity. And yet, this can take hours. There is no clear indication how long it will take for a butterfly to emerge from her chrysalis. One the red of the wings is visible it could take anywhere between minutes, up to the length of a day. And so being able to witness the “eclosure” is a matter of patience and also of luck. The author spent just over two hours waiting for the second chrysalis to eclose, as the first (the female) had emerged overnight. Rather than staring for the entirety of those two hours, the author did risk moving back and forth between tasks, hoping to luck that the timing would work out. And after several hours in the early afternoon, a telltale, tiny, almost plastic-like “crack” became audible, and that was the only sign needed to know that something amazing was about to take place.


A timelapse of the second butterfly as he emerges from his chrysalis. The entire process takes less than a minute to occur. Photo credit: Stephanie Rathsack


With what can be imagined as great strain, the butterfly pushes his legs and head against the walls f the paper thin chrysalis, which breaks along two lines—creating a piece that may be lifted up, similar to a door. This gives the butterfly an exit through which he can pull himself out by grabbing the chrysalis with his front legs and tugging hard. It’s amazing to see the butterfly come out of the chrysalis, as he still looks very chrysalis-shaped, despite the clear anatomical changes (wings, for example). His abdomen however is still the large bulbous shape of the top end of a chrysalis, and it falls down dramatically heavy once free to do so. Once the abdomen has dropped, it’s only seconds before the wings follow suit and suddenly the entire butterfly is visible—small, shrunken, and damp, but visible. He clings for life upside down to the chrysalis which had once been a part of himself, like a kid on the monkey bars. Hanging in this manner allows hemolymph (the insect alternative to blood) to flow from the abdomen into the wings, this “pumping” them up to their full size. As this occurs, the wings will enlarge and the abdomen will shrink. He also seems to experimentally flick out his proboscis—the new mouthpart with which he will feed with for the rest of his life. It’s much different than the leaf-cutting mouthparts of a caterpillar. Just minutes after emerging, the proboscis is actually split in two, and will fuse together into one apparatus while the monarch hangs. This “zippering” of the two halves is essential as it is their merging that creates the hollow “straw-like” central cavity through which the monarch’s entirely liquid diet will be “slurped”.

The process of drying takes much longer than eclosing, and in fact, for the first twelve hours, a monarch is generally unwilling or unable to fly or feed. But even after a half hour, he begins to look more full-formed, though still remains vulnerable. It’s important that they are not touched or moved during this sensitive time period, as this can damage their development, and a fall at this stage could even prove fatal.


Both the male (left) and female (right)  hanging from their respective chrysalises as seen at 1:22 pm on Tuesday June 20th. The third chrysalis (middle) is not yet ready to emerge, and would not eclose until the next day. Photo credit: Stephanie Rathsack


After being left to their own devices until completely dry, the next step in the rearing process will begin: keeping and caring for adult butterflies. Generally this is an unnecessary step, and amateur or beginner monarch keepers should attempt this with the greatest care.


A monarch clings to his now empty chrysalis with hooked feet. The ring of gold is somewhat dimmed now, which suggests that its metallic coloring was due in part to yellow pigments (still visible on the empty chrysalis) and the concave curves of the butterfly inside (now lacking after the butterfly emerged). Photo credit: Stephanie Rathsack


Adult monarchs are notoriously difficult to maintain, unlike their younger counterparts. They require larger spaces, proper lighting, and appropriate food daily. The first step in caring for them, actually involves a bit of science. The health of the butterflies needs to be determined, as rearing infected monarchs can prove detrimental for the species if allowed to spread the disease. In order to do this, a “Tape test” is administered—which should NOT be attempted without prior experience. It involves taking a piece of clear tape and gently pressing it to the sides of the butterfly’s abdomen—removing some scales in the process. This does not harm the butterfly. The tape is then placed on white paper and observed under a microscope.

The scales on a monarch’s forewing each have a distinct color which makes up the bright pattern which warns of poison. Photo credit: Stephanie Rathsack


To safely handle a monarch, hold all four wings together and pinch gently on the top ridge where the wings are most rigid. Photo credit: Stephanie Rathsack
Scales from a monarch’s abdomen are visible on the piece of clear tape. Photo credit: Stephanie Rathsack



Looking at the scales under a microscope to determine the health of the monarch butterfly. Photo credit: Stephanie Rathsack


When viewing the scales under the microscope, what you’re searching for are small spores from the obligate protozoan parasite Ophryocystis elektroscirrha which uses both the monarch and the queen butterfly as hosts. Infection from this protist can cause deformity in large amounts and even prevent the monarch from emerging from its chrysalis.



The spores of OE are very small in comparison to the butterfly’s scales.
Photo credit:


The third chrysalis emerged on the afternoon of the 20th. Photo credit: Stephanie Rathsack



After testing, it was found that all three of River Bend’s monarchs were healthy and free of parasites and were placed in a large free-flying enclosure where they will feed actively every day and also begin courtship before laying eggs and starting the life cycle all over again.


The female and one of the males perform pre-mating courtship behaviors. Photo credit: Stephanie Rathsack


Want to learn more?


Stop by our interpretive center any day during the week to talk to a naturalist and see the monarchs for yourself! The building hours are as follows:

Wed-Fri 8:00-4:30

Sat 9:00-4:30

Sun 9:00-2:00


Interested in getting more involved?


River Bend will be offering MLMP trainings to teach interested members of the community to become certified MLMP volunteers! Monitor at home or at River Bend, and help save this amazing insect from extinction.

Register online to attend the training scheduled for July 29th from 1:00-4:00pm.

For more information, see our website at:


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