The Amazing Monarch Butterfly Can Be Raised — By You
“The caterpillar does all the work, but the butterfly gets all the publicity.” — George Carlin
There is nothing quite like seeing a monarch butterfly (Danaus plexippus), our best-known and most popular butterfly in North America. Its large size and brilliant orange, black and white colors are distinctive and recognizable.
The monarch butterfly is a monophagous species, which means that during one stage of its life, it relies on a single food source, and for the monarch that is milkweed. Other animals with this characteristic include the panda bear with its reliance on bamboo.
The monarch butterfly and caterpillar are aposematic which means they warn predators of poisonous characteristics with their bright colors. The milkweed, which the caterpillar exclusively feeds on, gives it a poisonous bitter taste and greatly enhances survival from predation.
I have written about the monarch butterfly in a previous Bulletin column and want to share with readers information I received from my friend Bet Zimmerman-Smith on how you can help this important butterfly by raising them from caterpillar stage to adult butterfly.
The monarch goes through four stages of complete metamorphosis from egg to butterfly. The female will lay 250 to 1,000 or more light green eggs on the underside of milkweed leaves. When the eggs hatch, the larva or caterpillar feeds on the milkweed and undergoes five growing periods or “instar.” By the time the caterpillar is fully grown it can be up to 45 millimeters long and 8 mm wide, and has a pattern of white, yellow and black transverse bands. It also has pairs of black tentacles with one pair on the thorax and another on the abdomen.
The fully-grown caterpillar will begin the pupa or chrysalis stage by spinning a silk pad on a horizontal surface and then hang from this pad upside down in the shape of a J.
It will shed its skin, form a green exoskeleton and chrysalis and release enzymes that, literally, digest its body. What is left inside the chrysalis is no longer caterpillar but not yet butterfly, a mostly nutrient-rich goo from which the butterfly will begin to form.
After about two weeks, the adult butterfly emerges to feed on a variety of nectar plants including asters, thistles, coneflowers, goldenrod, lilac and red clover.
My friend Bet and her husband, Patrick Smith, have two patches of about 10 by 15 feet of milkweed plants near their house in Woodstock. They also maintain a 30-acre wildlife habitat property nearby that includes a 3-acre sunny meadow of with hundreds of milkweed plants.
Bet and Patrick have sown milkweed seeds to help increase the available plants for the monarchs. The patches had both swamp and common milkweed with both types having beautiful fragrant flowers. She reports that it is the common milkweed that seems to be preferred by the monarch butterfly for laying eggs.
This year they scoured their milkweed patch for monarch caterpillars and took them with milkweed leaves to raise in their house in a special bug cage. In the bug cage they provided milkweed leaves for the caterpillars, enjoyed watching them eat, transform into a chrysalis, and eventually into an adult butterfly which they released back outdoors. Here are several notes Bet sent me about their experience raising monarch butterflies.
- Bet and Patrick may have seen more monarch caterpillars this year because they let two big patches of milkweed grow – swamp and common milkweed.
- Every day was like an Easter Egg hunt the couple went out to scout for new hatchlings. To find a caterpillar, look on the bottom of milkweed leaves that have been chewed.
- Bet and Patrick had not realized Monarchs go through four generations each year. The first, second and third generation butterflies only live about a month – long enough to lay eggs.
- The last batch, which hatches out starting in August, will migrate all the way to Mexico to overwinter. They are the great-great grandparents of the first generation that comes back north between April and June.
- Bet and Patrick collected about 70 locally grown caterpillars, with 60 that successfully transformed into butterflies. The other 10 either died in the caterpillar stage, failed to develop a chrysalis, failed to hatch (probably due to a virus); or fell right after hatching and ended up with crumped wings. In the wild, only an estimated 5 percent of eggs make it to the butterfly stage.
- When rearing monarchs at home or in the classroom, some losses are to be expected. It is sad to lose any, but it is so much fun to free them!
- It was fascinating to watch the boldly black, white and yellow striped caterpillars munching away, then climbing up to the top of the butterfly habitat, attaching themselves by some silk and forming a “J” shape, and eventually wriggling into a green “sleeping bag” that hardened into a green chrysalis with what looked like a ring of gold leaf around the top. (It is hard to find a chrysalis in the wild, as the caterpillars ready to metamorphose leave the milkweed plant.)
- The butterfly emerges from the chrysalis looking very rumpled and needs to pump up its wings (like pumping air into a bicycle tire) and dry out before flying off.
- Male Monarch butterflies have a black spot on each of their hind wings. The female has thicker black webbing on the wings, and no spots.
If you’re interested in raising monarch butterflies, here are some of Bet’s tips and suggestions for what you will need:
- A source of fresh milkweed leaves. Caterpillars need fresh food every day. They eat a lot, and as a result create a tremendous number of droppings.
- A small “bug cage” is handy if you just want to raise one or two caterpillars and is also useful for bringing the butterflies outside for release.
- Bet liked the critter case or https://tinyurl.com/ya7thob9 or critter barn https://tinyurl.com/y8txvt9y both of which can be found for less than $13, and would make a great gift for large and small humans.
- A bigger butterfly habitat is better if you want to raise more caterpillars, as overcrowding can cause or spread disease. Bet got a pop-up mesh habitat that was about two-feet tall, with a zipper opening and a clear side for viewing. https://tinyurl.com/yap5d2aa. It was less than $11 and had plenty of room for all our caterpillars. Bet liked that she could put a small, sturdy vase in it to keep the daily batch of milkweed leaves fresh.
- Lay down a piece of newspaper (to replace daily, as it will get covered with droppings) in your habitat.
- Put the caterpillar inside (don’t touch them with your fingers) on fresh milkweed (replace daily) and then just watch!
- Some people even collect eggs to hatch, or newborn caterpillars, but Bet and Patrick had better luck with bringing in larger caterpillars.
- Timeline: About four days for eggs to hatch. Baby caterpillar is fully grown in about two weeks (depending on temperatures and food supply). The chrysalis phase lasts about 10 days.
- When the butterflies hatch, do not disturb them for the first four to five hours as they complete their transformation.
- Then release them outdoors near sources of nectar like zinnias, verbena, chives, salvia or butterfly bushes.
There are several on-line resources about monarch butterflies and conservation efforts for this unique and amazing insect. The North American Butterfly Association is a good place to start at this link: http://nababutterfly.com/monarchs-and-milkweeds/
There are also sources on-line for milkweed seed, including American Meadows at: https://www.americanmeadows.com/wildflower-seeds/milkweed-seeds/common-milkweed-seeds
We are fortunate to live in our beautiful region — The Last Green Valley National Heritage Corridor. We are also thankful to dedicated people like Bet Zimmerman-Smith and Patrick Smith for doing their part to help one of our more interesting butterfly species — the amazing monarch.
Bill Reid is the Chief Ranger of The Last Green Valley National Heritage Corridor and has lived in the region for more than 35 years. He can be reached at email@example.com
Sign up for our newsletter