Egg Gallery

Female Monarch Laying an Egg

This female monarch is laying a single egg on the bottom of a common milkweed (Asclepias syriaca) leaf. She will lay between 300 - 500 eggs on average during her lifetime.

Monarch Egg

Monarch eggs are approximately 1 mm wide by approximately 2 mm long.

Monarch Egg on Milkweed Leaf

Monarchs often lay eggs on the underside of milkweed leaves, which provides protection while they are developing. They can also be found on the tops of leaves, but that exposes them more to the elements as well as predation from above.

Monarch Egg

Monarch eggs are so tiny (1mm X 2 mm) that it can be difficult to see them clearly without a hand lens. The longitudinal lines help differentiate them from other insect eggs, which can be very helpful. They are typically cream-colored to white when laid, and become darker as they get closer to hatching.

Three Day Old Egg

Monarch eggs develop very quickly. They may hatch between 3 and 6 days after being laid. The hotter the temperature, the faster they develop. This three day old egg is already showing signs of the caterpillar inside.

Late Egg - Ready to Hatch

Notice the black spot at the top of the egg shell? That is the head capsule of a monarch caterpillar. When it hatches, it will almost always turn around and eat its shell before starting on milkweed.

Egg Loading on Common Milkweed Leaf

These eggs were laid on the same leaf and very close together. This is called egg loading and is a problem for emerging caterpillars, since they will be faced with competition as soon as they hatch. Females typically lay eggs on separate leaves and plants, but may lay many at once due to lack of suitable milkweed in the area or the need to quickly lay her eggs for another reason. Eggs are often laid on young leaves near the top of the plant and can be found on plants less than 6" tall.

Extreme Egg Loading

This showy milkweed (Asclepias species) leaf had nine eggs on the bottom and two on the top. This is a clear sign of there being a serious lack of milkweed, or maybe not healthy enough milkweed in the area, or the female monarch needed to lay her eggs quickly for another reason.

Monarch Eggs on Common Milkweed Leaf

This photo shows two monarch eggs on the underside of a common milkweed (Asclepias syriaca) leaf. The tiny head capsules are visible, so the caterpillars inside will soon hatch, and begin their journey as a first instar.

Milkweed Droplet

When looking for eggs to report to monarch organizations, sometimes milkweed drops can look a lot like monarch eggs. Note that is it on a vein, which happens often with droplets. The next image is a close-up of the droplet.

Milkweed Droplet Up Close

You can see that the milkweed droplet is more round, and very white. There are no longitudinal lines and it isn't the ovate shape of a monarch egg. If you look at one through a hand lens, you can easily tell the difference. At first glance, however, it can be a little tricky!

Aphids Taking Over a Milkweed Leaf

These oleander aphids (Aphis Nerii) are taking over this common milkweed plant. They won't eat the tiny egg on the right near the end of the leaf, but they will suck the juices from the milkweed leaving it dried out and covered in their sticky waste, called honeydew. Because honeydew attracts ants, and ants are a predator of monarch eggs, this egg has little chance of survival.

Eggs on Top of a Leaf

There are two eggs on this showy milkweed (Asclepias species) leaf. There are a few things wrong with this location. The first is that they are exposed to the elements. They are also easier to see by predators. Since there are two eggs, the caterpillars that hatch will be competing for food, and lastly there was already at least one monarch on the leaf judging by the holes and edges that have already been eaten.

Monarch Egg on a Stem

Monarchs don't always lay their eggs on leaves. They can also lay them on stems, flowers and pods.

Empty Egg Shell

This empty egg shell is a bit unique. Not all first instars eat their shells. A few will move right onto milkweed leaves. This could also be an indication that the caterpillar was eaten before it could eat its shell.

Hatching Slide

Hatching Gallery & Video

Head Capsule Becoming Visible (1 of 9)

Head Capsule Darkening (2 of 9)

Head Capsule Darkening (3 of 9)

Egg Ready to Hatch (4 of 9)

Chewing Egg Shell (5 of 9)

Hatching (6 of 9)

Hatching (7 of 9)

Hatching (8 of 9)

Hatched and Eating Shell (9 of 9)

Video: Monarch Egg Hatching

Monarch eggs are about 1 millimeter in size. When the tiny caterpillar hatches, it is approximately 2 millimeters long, creamy white with few markings. Once they hatch, they will often feed on milkweed hairs and their egg shell.