Monarch Caterpillars

The tiger-striped monarch caterpillars are among the most beautiful of the caterpillars. Monarch caterpillars often hatch and eat milkweed plants. This is useful for the caterpillar and the butterfly because the toxins from these plants pass to the insect, making them unpleasant to predators such as birds. Even if an ignorant bird tries to eat a monarch caterpillar, its bad taste will deter the bird from eating others.

The caterpillar is only the second stage in the life cycle of the monarch butterfly. It begins as an egg laid on the milkweed plant. The female butterfly will glue the eggs to the plant leaf with her own body secretions to make sure they are safe, then she will leave and stop caring for the eggs or larvae.

When it’s time for the caterpillar to emerge, it will chew a circular cap on the shell of the egg and then lift its body out of the egg. The eggshell will then be eaten, giving you some nutrients before you start eating milkweed.

Like all caterpillars, the monarch caterpillar’s task is to simply eat and eat until it reaches the size where it will be ready to pupate. This is about two inches long and takes about two weeks. Once the caterpillar has reached this size and survived predators and other hazards, it will find a location (usually away from the milkweed) and spin a pad there. It will connect its backside to the pad with hooks and it will hang in a “J” shape for approximately twenty-four hours.

Then the skin of the caterpillar splits down the back and the pupa emerges. It comes loose from the skin which eventually comes off. The pupa then hardens and waits.

Even the pupae of monarch caterpillars are attractive. They are mostly jade green in color and have beautiful gold-looking dots on the top and sides.

During the pupal stage, the body of what was the caterpillar decomposes into something similar to a soup and little by little it transforms into the adult butterfly. This drastic process is known as complete metamorphosis.

Eventually, the pupal case divides and the monarch butterfly comes out fighting. After it emerges, the butterfly rests for a while. Their wings are wrinkled and wet and cannot work right away. The butterfly spends a couple of hours pumping fluid into the wing veins so they can expand and harden properly. The monarch butterfly then flies off to start the process over. The time between the egg and the adult is approximately one month.

Milkweed or butterfly weeds are easy plants to grow in a garden. Growing to about a meter tall, these plants have beautiful clusters of flowers that bloom from June to August and do well in zones 3 through 10 and throughout the United States.

Planting milkweed will bring the beautiful monarch caterpillars into your garden so you can enjoy the entire wonderful life cycle of the butterfly!