What Is Müllerian Mimicry?

Examples of Müllerian Mimics

Heliconius butterflies.
Heliconius butterflies are examples of Müllerian mimics. Axel Meyer (CC license)

In the insect world, it sometimes takes a little evolutionary teamwork to fend off all those hungry predators. Müllerian mimicry is a defensive strategy employed by a group of insects. If you pay attention, you might even be able to see it in your own backyard.

The Theory of Müllerian Mimicry

In 1861, English naturalist Henry W. Bates (1825-1892) first offered a theory that insects use mimicry to fool predators.

He noticed that some edible insects shared the same coloration as other unpalatable species.

Predators quickly learned to avoid insects with certain color patterns. Bates argued that the mimics gained protection by displaying the same warning colors. This form of mimicry came to be called Batesian mimicry.

Almost 20 years later in 1878, German naturalist Fritz Müller (1821-1897) offered a different example of insects using mimicry. He observed communities of similarly colored insects and all of them were unpalatable to predators.

Müller theorized that all of these insects gained protection by displaying the same warning colors. Should a predator eat one insect with a certain coloration and find it inedible, it would learn to avoid catching any insects with similar coloration.

Müllerian mimicry rings may arise over time. These rings include multiple insect species from different families or orders that share common warning colors.

When a mimicry ring includes many species, the probability of a predator catching one of the mimics increases.

While this may seem disadvantageous, it's actually quite the opposite. The sooner a predator samples one of the unpalatable insects, the sooner it will learn to associate the colors of that insect with a bad experience.

Mimicry occurs in insects as well as amphibians and other animals that are vulnerable to predators. For example, a non-poisonous frog in a tropical climate may mimic the color or patterns of a poisonous species. In this case, the predator does not have just a negative experience with the warning patterns, but a lethal one.

Examples of Müllerian Mimicry

At least a dozen Heliconius (or longwing) butterflies in South America share similar colors and wing patterns. Each member of this longwing mimicry ring benefits because predators learn to avoid the group as a whole.

If you've grown milkweed plants in your garden to attract butterflies, you might have noticed the surprising number of insects that share the same red-orange and black colors. These beetles and true bugs represent another Müllerian mimicry ring. It includes the caterpillar of the milkweed tiger moth, milkweed bugs, and the very popular monarch butterfly.