A Students Guide to Butterflies
Module 5: Defense Mechanisms
Throughout the four distinct phases of their lives, butterflies exhibit many peciluar and unusual characteristics in the form of: colors, appendages, camoflouge, etc. Why is this? Much of the answer lies in the fact that butterflies are essentially food to the many hungry animals and insects which are known as predators. There is little that would not want to eat a butterfly in one stage or another, and the following is an abbreviated list of some of these predotors: ants, spiders, wasps, parasitic wasps, parasitic flies, birds, rats, toads, lizards, praying mantis, snakes, and monkeys.
Through years and years of evolution and adaption, butterflies have developed many means to protect themselves from these predators. Below we will talk about a few different defense mechanisms in the stages of the butterfly life cylce.
There are numerous examples of camoflouge used by butterflies in all different stages of their life cycle. This camoflouge helps them blend in with their surroundings and elude this long list of predators. In the egg stage of the butterfly, we can see this trait very well in the eggs of the Blue Morpho (Morpho spp.), which blend themselves very well with the color of its host plants in the family Leguminosae.
In the small picture here to the right we can see the small eggs of the Morpho laid singly on the host plants. These eggs are nearly transparent, and after a rain, when there are raindrops on the surface of the leaves, these eggs are incredibly hard to distinguish and pick out from the raindrops.
In the larva and pupa stages of butterflies we can see numerous examples of how different butterflies use certain colors and patterns on their exoskeleton or chrysalis to deter or fend off predators. In some species, these traits come in the form of colors which blend themselves in within the branches of their hostplant, while others actually appear like a whole different organism which a predator would not dare to mess with, such as a snake. Here on the left we can see an example of how a Morpho pupa is appearing much like an unripe fruit as it hangs from its host plant.
Toxic Butterflies and their Mimics
Bad tasting butterflies are colorful as adults and have toxins in their bodies that make the predator sick. The predator once having suffered the consequences of consuming such a butterfly will easily remember the bright color of the wings. It will know from that time on to avoid that color pattern. Although one butterfly will be killed from such an encounter, many more will live.
Good tasting butterflies are butterflies that, when eaten, are agreeable with the consumer and most defend themselves accordingly. There are two ways to do it. To be good tasting and bright is dangerous for an appetizing butterfly. Therefore the good tasting species camouflage themselves by using dull colors which blend into their surroundings well.
Mimicry is another effective defense. It is used by brightly colored species that are also good tasting. Their bright color patterns have evolved to appear like those of the poisonous butterflies. One example is the orange and black colored Viceroy which is strikingly similar to the poisonous Monarch. A predator that's experienced a monarch would never again venture consuming another orange and black specimen.
This information is provided by Evan Fitzgerald, who was an intern at The Butterfly Farm in 1999. Evan graduated from the University of New Hampshire with a Bachelor's Degree in Environmental Science in May 1998. Evan can be reached at: firstname.lastname@example.org.
[To Return to the Index of Modules]