Butterflies: Beautifully Designed!

Before looking at the design in butterflies, it is important to remember that butterflies are small insects with pinhead-sized brains, no bones, no blood, and a minimal nervous system. These facts make many of the things they can do even more astounding and point strongly to God’s design in creation.

Butterflies must also maintain specific body temperatures to function. The black swallowtails (Papilio polyxenes) bask in the sun to raise their temperature, raising and lowering their abdomen depending on temperature. To reduce temperature, they can increase the circulation of hemolymph between their body segments to dissipate heat into the environment!1 Eastern tiger swallowtails (Papilio glaucus) lay eggs on the tips of branches facing the sun, which is very important as larvae exposed to sunlight develop up to 35% faster than those not exposed.2 Monarchs (Danaus plexippus), for which flight is essential to both migration and normal life, shiver to increase body temperature to a level where flight can occur.3 Painted lady butterflies (Vanessa cardui) also exhibit shivering, though there is a wide variation between individuals in its use.4

Designed Defenses

It is well-known that some butterfly species, like the popular monarch butterfly, are noxious to predators due to consuming plants with a foul taste as caterpillars. Other butterflies take advantage of this by mimicking the noxious butterfly. The black swallowtail mimics the blue swallowtail (Battus philenor). Females are better mimics than males in this instance,5 but males only fare worse when predators can see the dorsal surface of the wing. From beneath, protection is the same.6 The related eastern tiger swallowtail likewise exhibits female mimicry of B. philenor.7 The red-spotted admiral (Limenitis arthemis) also imitates B. philenor to varying degrees depending on the population.8

Black Swallowtail male. D. Gordon E. Robertson, CC BY-SA 3.0, via Wikimedia Commons

Eastern Tiger Swallowtail female. Photo by and (c)2007 Derek Ramsey (Ram-Man), GFDL 1.2, via Wikimedia Commons

Many caterpillars are designed to feed on plants with chemical defenses that make them unpalatable to other insects. The most obvious example of this is the monarch, which feeds on noxious milkweed, but there are others. The black swallowtail caterpillars feed on plants with chemicals that produce oxidative stress. As such, they have much higher levels of antioxidants to combat these chemicals than other insects.9 This species also has enzymes that are designed to quickly break down other toxins in the plants they eat.10 A subspecies of the related eastern tiger swallowtail can eat the highly toxic leaves of the Salicaceae family of plants and show good survival rates.11

Some butterflies can modify certain aspects of their behavior or coloration depending on their environment. In the black swallowtail, when the caterpillar forms its pupal stage, it tracks the amount of light it receives and alters the color of its pupa accordingly!12 The zebra swallowtail (Eurytides marcellus) pupa will modify its color to match its environment.13 Texture may also play a role in the coloration.14 The common buckeye (Junonia coenia) changes the color pattern on its wings in response to the seasons, helping it control its body temperature.15 The painted lady modifies the colors of its wings in response to environmental stressors.16 The eyespots on its wings also change in response to both cold and heat shock.17 Despite their tiny brains, cabbage whites (Pieris rapae) can learn to recognize flowers containing nectar and remember them for up to three days, even while learning a second flower!18

Common Buckeye. Rhododendrites, CC BY-SA 4.0, via Wikimedia Commons

Cabbage White male. Ypna, CC BY-SA 3.0, via Wikimedia Commons

Butterfly Migration

Migration is well-known in some butterflies like monarchs, but they are far from the only ones. Painted lady butterflies also mass migrate, using the location of the sun as a compass for navigation.19 The butterflies also somehow know how to take advantage of wind currents to migrate more efficiently.20 Some of these migrations can be nearly 2,500 miles in a single generation21 for a butterfly smaller than a child’s hand! Some populations of the cabbage white butterfly (Pieris rapae) also migrate. They migrate largely with their backs to the sun, sometimes crossing mountain ranges regularly between spring and fall.22

Specialized Plant Preferences

Many butterflies require specialized host plants for their larvae. The obvious one is a monarch butterfly, but there are others. For the caterpillars to survive, mother butterfly must be able to identify the proper place to lay her eggs. Some species do this by tracking substances released by plants called volatiles. The black swallowtail can track the volatiles of its host from the time they first fly, and they get better at identifying the source of the volatiles as they get older.23 Male and female monarch butterflies do something similar, tracking volatiles of milkweed to find places to lay eggs.24 Females of the common buckeye also show preference for particular plants, sensing the presence of iridoid glycoside and preferentially laying their eggs where the highest concentration of it was located.25 Cabbage whites also can track their preferred host plants using their volatiles, showing a preference for a nonoptimal host treated with a host’s volatiles.26

Monarch female

Only the almighty Creator of the universe could make something so beautiful and so brilliantly functional.

As we can see, butterflies have some very unique attributes that enable them to survive and even thrive in our fallen world. Their ability to track and control their body temperatures, mimic poisonous butterflies, modify their colors and behaviors at will, identify host plants by smell, and migrate long distances by relying totally on the position of the sun shouts God’s design. How does a tiny insect, with a brain the size of a pinhead, know how to use the sun as a compass? Something like that is far beyond the power of a human engineer and even further beyond the power of natural processes. Only the almighty Creator of the universe could make something so beautiful and so brilliantly functional.