Monarch Primer & Update: Mid-August 2020

It’s mid-August!

This means that it is time to start tagging monarch butterflies!

The monarch’s life cycle is amazing! Monarchs undergo what is referred to as a complete metamorphosis, or change in form. This is accomplished through four stages.

Stage 1

Stage 1 is an egg. It is a tiny, pale yellow oval, usually found on the underside of the milkweed leaf.

Female monarchs seek milkweed plants to lay their eggs so that when the eggs hatch after only about four days and the caterpillar or larva emerges, it has a ready source of food. When you realize how truly small the larva is when it hatches, it is a good thing the caterpillar does have to go anywhere to reach food. Milkweed is the only food that sustains this species. There must be milkweed for the monarchs to survive!

Stage 2

The caterpillar is the second stage of the life cycle of the monarch. In ten to fourteen days, the teeny tiny caterpillar grows many times over and sheds its shed a total of five times. The molting or shedding of the skin is necessary to accommodate the exponential growth and change in size. It would be like a female human going from a size 0 to 18 in a year! The skin can only stretch so much!  The job of the larva or caterpillar is only to eat, excrete, and growth. Likening it to an eating machine is an understatement! An entire milkweed plant can easily be defoliated by a single monarch caterpillar!

By the end of stage two, the caterpillar is about 2.5 inches long if they’ve eaten heartily. The easily recognizable stripes of black orange and white are bold and stand out on the verdant milkweed leaves. But, as it comes time to get ready for stage 3, the caterpillar roams away from its food source. This is a protective mechanism and finding a safe place to pupate is essential.  You can tell a monarch is getting ready to pupate when it attaches itself to a twig or other such object from which it can hang. There, it hangs upside down in a J shape. After some time, usually close to a day, the caterpillar splits and sheds its skin for the fifth and final time.  He wriggles out of it, twisting and turning to further secure itself to the place will it will complete metamorphosis.

Stage 3

When the skin comes off and falls to the ground, what is left becomes a chrysalis or “hard case.” It is inside the chrysalis that the monarch caterpillar changes into a monarch butterfly. This process is called metamorphosis.

Metamorphosis takes approximately 10 days but can take up to 14 depending on factors like temperature.

In my opinion, the chrysalis is one of the most beautiful things in the natural world.

When the skin comes off the caterpillar it falls to the ground revealing a soft green color. The outer part of the chrysalis hardens to contain what is going to happen inside golden rim forms near the top and several gold “dots” are visible near the bottom of the chrysalis. It is thought these help with camouflage.  Slowly, the cells reorganize and change what was once the caterpillar into a butterfly.  By the end of the pupation (another name for stage three is the pupa stage), the wing pigments or colors are visible through the clear chrysalis. This is one of the last changes to take place. When the wings are visible through the chrysalis, you can count on an eclosure soon. An eclosure is the emergence of the butterfly from the chrysalis.

The butterfly emerging from the chrysalis is an event that happens quickly, but if lucky enough to capture, it is one of the most awe-inspiring things you’ll ever witness.

There are four generations of monarchs a year. Each generation, except for the last, lives for about a month during the breeding season in the mid-west.  The last, being born now is referred to as the Super Generation. This is in reference to the migratory journey that they’ll undertake in the fall. The super generation monarchs fly to the Sierra Madre Mountains of Mexico to overwinter.

For the last six years, I have tagged the monarchs that I raised during the summer. Tagging only takes place for the last generation of monarchs, since theirs is the cohort that migrates. Today, I will tag my first monarch of the season.  It’s always exciting!

My knowledge of the monarch life cycle has grown since 2004 when I first started raising them and providing habitat at home and in school gardens.  It stems from a voracious reading on the subject, a passionate interest in their conservation, and practical experience.  If you are interested in learning more, the websites of Journey North, Monarch Watch, and Monarch Joint Venture are great places to start!