The Viceroy butterfly (Limenitis archippus) is smaller and yet similar to a Monarch butterfly. The connection to Monarch and other milkweed butterflies from the Danainae subfamily is distant. But, this relationship is Müllerian which means that these species are unpalatable to birds and in this way, they do contribute to the survival of each other. The Mullen phylogenetic study in 2006 showed that Limenitis butterflies began as black and white and they evolved a mimetic species quickly.
The Viceroy butterfly is one of these species and the wing pattern changes may have occurred before the species developed a chemical defense. So, this butterfly may have started as a Batesian, which means that it evolved mimicry to imitate warning signs of harmful species first.
Over time, the Viceroy butterfly mimicry became Mullerian mimicry which means that two or more species developed biological resemblance to spread a dangerous reputation amongst potential predators.
A Viceroy Butterfly Overview:
The Viceroy is a brush-footed butterfly with tiny hairy forelegs that look like little brushes and they are not used for walking. This butterfly has a dark orange coloration with prominent black veins and white spots that edge the wings. The patterns and colors are similar to a Monarch butterfly, but there is no black horizontal stripe across the bottom of the back wings.
The Viceroy caterpillar has an olive-brown and white coloration and it eats the leaves of poplar and willow trees. A Viceroy butterfly eats the nectar of Asteracenae family flowers like asters, thistles, and goldenrod, and it may supplement this with fungi, dung, and carrion.
Viceroy butterflies can be found in most of the U.S., southern Canada, and northern Mexico. Their preferred habitat is meadows, swamps, marshland, and wet areas where poplar and willow trees grow.
What is Mimicry?
Viceroy butterfly mimicry is not unique. This form of protective coloration can be found in other species too. The mimic can increase its survival chances if it visually resembles a harmful species.
Potential predators, such as reptiles, birds, and predatory insects, will become confused between the original and the mimic and avoid hunting them. The model that the mimic resembles may be another butterfly or it could be an entirely different animal species.
This mimicry strategy includes camouflage strategies which are known as Masquerade. A butterfly that uses this strategy can mimic objects, such as tree bark, leaves, lichen, and more.
The Viceroy butterfly uses Mullerian mimicry; they look unpalatable or poisonous like the species they are modeling, but they are toxic in different ways.
Viceroy Butterfly and Its Mimicry
The Viceroy butterfly or Limenitis archippus is a Monarch mimic even though they are not a closely related species. The Viceroy mimicry was initially referred to as the aforementioned Batesiam mimicry. This term is named for Henry Walter Bates who made the discovery that certain species may falsely mimic aposematism in other species.
This was found to be common in many species of butterflies, snakes, and even plants. Biologists use the term Aposematism to refer to colorful pairings of red and orange with black to warn potential predators to avoid them. The predator makes the assumption that those species are either toxic or dangerous to eat.
In the case of Monarch butterflies, they are toxic to invertebrates and any bird or mammal that decides to make a meal of them will be affected. But, recent studies have revealed that Viceroys are also toxic when consumed. They have a different toxicity than Monarch butterflies, which changes their definition from a Batesion to a Mullerian form of mimicry.
Mullerian co-mimicry
Mullerian co-mimicry is when two or more species have similarly evolved appearances with an accompanying toxicity or foul taste if they are consumed. In nature, this multiplies the efficacy of the warning signals, and predators soon get the message that species with Mullerian co-mimicry are unpleasant or even dangerous to eat. This is a clear example of evolutionary adaptation used by Monarchs and Viceroy butterflies to benefit the survival of each other which is fascinating.
Although predators can be fooled by Mullerian co-mimicry, it’s not as easy to fool human biologists that have dedicated themselves to studying these species. Upon closer inspection, a Viceroy butterfly has a thinner black line that extends in an upward curve across the hind wing and a Monarch doesn’t have this feature.
Monarchs tend to be a little larger on average and they have a slightly duller coloration than Viceroys. Viceroys don’t migrate and they breed on willow trees, unlike Monarchs that prefer milkweed. A Viceroy caterpillar can survive colder temperatures as caterpillars and they don’t need to migrate long distances which tends to make their populations more stable.
Difference between Monarch and Black Swallowtail Butterflies
The Mullerian co-mimicry is not restricted to adult butterflies and this self-defense strategy extends to the vulnerable caterpillars too. A good example is the Black Swallowtail butterfly or Papilio polyxenes caterpillars that have a similar appearance to Monarch caterpillars.
The most reliable way to spot the difference between Monarch and Black Swallowtail caterpillars is to look at the front and rear filaments. Monarchs have filaments that resemble antennae and Black Swallowtails don’t have this feature.
Another key difference is that Monarchs have a series of white, black, and yellow stripes on their bodies. Black Swallowtails tend to have a fuller head when they are compared to Monarch caterpillars.
If you have difficulty observing these subtle differences, it’s a good idea to pay closer attention to the host plant to make things easier. Monarch butterfly eggs are only laid on milkweed because it’s the preferred diet of the emerging caterpillars.
Black Swallowtail eggs are laid on carrot, dill, celery, fennel, and parsley plants because the caterpillars have a more varied diet. If you observe a fat green caterpillar on the aforementioned plants it is likely to be a Black Swallowtail.
Viceroy Butterfly-In Conclusion
The mimicry of a Viceroy butterfly and the capability of this species to form hybrid variants by breeding with other North American Limentis are proven survival strategies. Bird predation studies have been carried out with Viceroys and other species with caged birds to test these theories on co-mimicry.
The Viceroy populations were kept in captivity to observe interbreeding within non-mimetic and mimetic Limentis species. They gave biologists the opportunity to observe how mimicry strategies evolved naturally to deter predators. If you’re lucky to see a Monarch and Viceroy in close proximity, the information in this article should help you to tell the difference between them.