Monarch Butterfly Eggs: What They Look Like & More

It’s hard to overlook the brilliant orange and black wings of a monarch butterfly as it moves through a garden of flowers. It’s also hard to believe that the life cycle of this incredibly colorful butterfly starts with a tiny egg. Continue reading to learn what monarch butterfly eggs look like, where they are laid, when they hatch, and more!

Where Are They Found?

Monarch butterflies lay their eggs on milkweed plants. They can be found on the undersides of leaves, stems, and even on the plant’s main stalk. These beautiful butterflies have a reason for laying their eggs on milkweed plants. When the larva, or monarch caterpillar, emerges from its egg, it starts to eat the milkweed plant right away. Milkweed plants provide nourishment to a monarch caterpillar so it can prepare for the pupal stage.

What Do Monarch Butterfly Eggs Look Like?

One way to identify the eggs is by their color. This butterfly’s eggs are off-white or white. They have an oval shape and are about one millimeter in size. A magnifying glass is an excellent tool if you want to take a close look at the appearance of a butterfly egg. A closer inspection of a monarch butterfly egg reveals vertical ridges running over its surface.

Their small size means you have to be looking carefully for these eggs on milkweed plants. They are normally found on the underside of leaves. This gives them some protection from passing birds and other predators. Not surprisingly, the appearance of butterfly eggs differs among the various types of butterflies. While monarch butterfly eggs are off-white and oval-shaped, the eggs of a Brimstone butterfly are pale green with a pointed end. Furthermore, the eggs of a small copper butterfly are white/gray with a surface resembling a golf ball.

Monarch butterfly eggs are laid in the spring and summer seasons. The process starts when a female butterfly lands on the leaf of a milkweed plant. She curves her abdomen toward the underside of the leaf and releases the egg onto the leaf’s surface. The egg is covered in a sticky substance, so it adheres to the leaf. A female flies from leaf to leaf, laying a single egg on each one. One female monarch butterfly can lay between 300 and 500 eggs. After attaching one egg to a leaf or stem, the female moves on to look for the next place to lay an egg. The larva inside the egg must develop and hatch on its own.

Monarch Butterfly Eggs vs. Aphids

Some people confuse aphids with monarch butterfly eggs. Why? Because they are both found on milkweed plants. In terms of size, both monarch butterfly eggs and aphids are about the same length. However, some basic differences between them can help with identification.

One of the most fundamental differences is found in their appearance. Aphids are brilliant yellow, whereas monarch butterfly eggs are off-white or white.

Aphids gather in large clusters right next to one another. There may be dozens of aphids in one cluster. Alternatively, monarch butterflies lay just a single egg on the underside of a leaf or a stem. As a note, some types of butterflies do lay clusters of eggs.

The larva inside a monarch butterfly egg doesn’t move around. However, it can take on a darker color as it nears hatching time. Alternatively, you’ll notice an aphid has six black legs. So, if you see something moving around on legs, you know it’s not a monarch butterfly egg.

How Long Do They Incubate?

Monarch butterflies have a short incubation period of three to five days before they hatch. In fact, their time in the egg is the shortest stage in their entire life cycle, with the resulting larva stage lasting two to three weeks after the egg hatches, the pupal (chrysalis) stage lasting five to 15 days, and the butterfly (reproductive) stage lasting two to five weeks in the first generation and several months in the second generation.

How Many Eggs Survive?

Typically, a single adult butterfly or moth can lay around 300 to 500 eggs. However, the vast majority, which is about 98%, do not survive to reach adulthood.

Throughout their pre-adult stages — from being laid as eggs, hatching, growing, and pupating, to maturing in chrysalis or pupa — these insects experience significant losses in their populations.

In captivity, Monarch survival rates tend to be considerably higher compared to the wild, where a combination of predators and other factors leads to loss. It is actually a fairly simple task to keep eggs alive.

A few quick morning spritzes of water will help keep the eggs hydrated and can also remove any potential disease spores. When using sealed food containers, which retain more moisture, only mist the leaves if they appear to be drying out.

What Eats Monarch Butterfly Eggs?

Butterfly eggs are vulnerable to birds, lizards, amphibians, and other animals that can eat them. Though monarch butterfly eggs are small and hidden on the undersides of leaves, they are still at risk of being eaten. The black-headed grosbeak is a well-known predator of monarch butterflies and their eggs.

Pesticides used in a garden may kill the larvae inside butterfly eggs before they get the chance to hatch.