What Do Caterpillars Eggs Look Like?

Contrary to popular belief, caterpillars don't lay eggs; they actually hatch from butterfly eggs that vary in color and shape and are usually tiny, the size of a pinhead.

Butterfly Egg or a Caterpillar Egg: The Common Misconception

The common misconception about caterpillars is that they lay eggs. Instead, they’re the second stage of a butterfly’s life cycle. Only adult butterflies lay eggs, and their life cycle consists of a total of 4 stages:

• Egg
• Caterpillar (larva)
• Pupa (chrysalis)
• Adult butterfly

How Do Butterflies Lay Eggs?

Butterfly eggs are fertilized when a female butterfly mates with her male counterpart. Depending on the butterfly species, females then lay a single egg or stick egg clusters to the underside of the leaves. Females typically pick the plant by the leaf color and shape, but they can also scratch the leaf surface with their feet and choose it by the odor the plant releases.

Butterflies lay anywhere from a dozen to hundreds of eggs in their adult stage. For example, a female Monarch butterfly lays about 700 eggs in her two to five-week lifespan, while a Black swallowtail butterfly usually lays from 200 to about 400 eggs.

How Long Does It Take for a Caterpillar Egg to Hatch?

The time it takes for eggs to hatch depends on the species of butterflies. For instance, Monarch butterfly eggs hatch within 3 to 8 days, similar to Painted lady eggs – in 3 to 5 days.

Then, the baby caterpillars hatch. As they break through, they may eat the eggshell and move to munch on the host plants later. The larval (caterpillar) stage of butterflies usually goes through several instars and molts until it makes a chrysalis.

What Color Are Butterfly Eggs?

Egg color depends on the butterfly species. They can be green, orange, white, dark brown, red, etcetera.

For example, Pipevine swallowtail eggs are bright orange, while Monarch’s are off-white. Brimstone butterfly eggs are pale-green, and Black swallowtails lay pale yellow eggs.

Where Are Butterfly Eggs Often Found?

Butterfly eggs are typically found on the underside of a leaf of a particular species’ host plant. Moreover, they can be seen on top of the leaves, in tree bark cracks, or in the flowers near the host plant.

The exact plant where the eggs are located depends on the butterfly species. For example, Monarch butterflies’ common host plants are various milkweed species. Silvery checkerspots prefer sunflowers and Great spangled fritillaries like violets. Additionally, these host plants attract the following butterflies:

• Golden Alexander – Black swallowtails
• Asters – Painted ladies, Silvery checkerspots, Pearl crescents
• Purple smoke or False indigo – Eastern tailed-blues
• Goldenrods or Solidago – Sulphurs, American coppers, Monarchs
• Spotted Joe-pye weed – Red admirals, Red-spotted purples

Besides herbaceous plants like these, certain woody plants are known as butterfly magnets. Some of these are:

• Spicebush – Spicebush swallowtails, Eastern tiger swallowtails
• The Flowering dogwood – American snouts, Question marks, Red-spotted purples, Hairstreaks
• Buttonbush – Skippers

You might also see butterfly eggs on tree leaves. Important host trees for butterflies include:

• Oaks – Hairstreaks, Horace’s Duskywings, Mourning cloaks
• Elms – Question marks, Eastern commas, Mourning cloaks, Hackberry emperors, and Tawny emperors