Butterflies: Effects and Physics
So …..I have a huge fear of butterflies and moths. Long story short, as a kid I was at a butterfly conservatory as I was standing so still looking at the chrysalids, that a bunch of Owl Butterflies started landing on me. All I saw were these massive eyes descending down on me…..It was traumatic.
So of course, telling my ex-partner about this story caused them to have a good chuckle, and so they dragged me into a butterfly exhibit at a science center. I figured the best way to get over my fear and his inflicted trauma was to write an article about it. So yes, I genuinely did enjoy researching this article, but overall did not enjoy the google search part. Thanks Andy…
All About Butterflies
Butterflies are insects. Their scientific family has a longer than average name. They fit into the macrolepidopteran clade Rhopalocera family, from the order Lepidoptera. A very fancy way of saying they are related to moths. Butterflies have existed for a long period of time. Fossils of them can be found dating back to 56 million years ago.
They are insects that have a four stage life cycle. They undergo a complete metamorphosis in order to reproduce. Their young emerge from eggs, which then produce caterpillars. These caterpillars then form a chrysalis in which they become a butterfly. Some butterflies can life for years, others only a few months.
Most butterflies are polymorphic. This means they use camouflage to avoid predators. They also have several other interesting characteristics. Some species will travel great distances to lay their eggs, such as the Monarch butterfly. Others are more prone to parasites. While all species are hunted by other insects and invertebrates.
Butterflies are most prone to parasites in their early developmental stages. While they can die from them in later stages as well, their growth is mostly affected by diseases and environmental factors. Because of this only a few eggs per butterfly ever reach full maturity. Braconid wasps will often attack these creatures and lay their eggs inside the insect. Then the wasp larva will slowly eat the butterfly from the inside out.
The earliest butterflies existed around 200 million years ago in the Triassic-Jurassic boundary. They evolved from moths, which are the older species of the two. The oldest butterfly is Protocoeliades kristenseni from the Palaeocene age in Denmark. It is thought that this species originated in the mid-Cretaceous period. The oldest American butterfly is Eocene Prodryas persephone. Which is around 34 million years old.
Quite a few butterflies are endangered. The largest butterfly in the world, the Queen Alexandra’s Birdwing is one of them. It is also one of only three protected insects that are illegal to trade internationally.
Even though these creatures seem to die from everything life can throw at them, it doesn’t mean they are completely useless. They have many defense mechanisms.
Various plants butterflies eat have chemical defenses. These insects have evolved to consume these toxins with no negative effects. This in turn led to the development of bright colors on the wings of these creatures. Some species have even adopted the colors of bird species in order not to be eaten. Other butterflies such as the oakleaf butterfly and autumn leaf resemble leaves and other foliage. A common tactic for caterpillars is to freeze and act like a stick in order to avoid being eaten.
The Lycaenidae is a bug that has evolved a bit differently from other insects. It has a false head for predators to attack. This head has false eyespots and false antennae. Other species have eyespots on the wings to deflect attacks and to attract mates.
Male butterflies will patrol or fly over an area where other butterflies are active or perch on tall plants in order to find a mate. A lot of these methods are not very effective over large areas.
Many tropical butterflies change colors depending on if it is a dry or wet season. If it is a dry season, the colors of the creatures will become camouflage oriented, as vegetation is more scarce. In the wet seasons, butterflies create more dark colors to absorb solar radiation.
Butterflies are cold blooded, and cannot regulate their own body temperature. As a result their body temperature changes with their surroundings. If they get too cold, they must warm up their muscles before resume flight. Their perfect range of heat is between 60-108 degrees Fahrenheit.
Butterflies are the most recognizable insects in any human language. There are about 17,500 species of these creatures around the world.
Butterfly and Moth Characteristics
So what makes butterflies and moths different?
Both of these creatures are the only group of insects with scales covering their wings. They both have the ability to coil up their proboscis. Both of their larvae are called caterpillars. They both belong to the group called Lepidoptera.
Butterflies are more closely associated with plants than moths. They help cross pollinate plants, and spread plant material. They feed on the nectar from flowers, as well as rotting fruit. Most butterfly caterpillars eat plants as well. Butterflies also tend to migrate, while moths don’t. Their vision is great for short distances, which makes them great at avoiding obstacles. Butterflies also have complex mating behaviors. They also have six different family groups: Hesperiidae, Lycaenidae, Nymphalidae, Papilionidae, Pieridae, and Riodinidae.
The main differences between moths and butterflies is as follows:
- Butterflies as clubbed antennae, while moths as furry or feathery ones.
- Butterflies are active during the daytime. Moths are active during the night.
- Butterflies rest with their wings held above their body. Moths rest with their wings spread out flat.
- Butterflies are often more brightly colored than moths.
The wings of these creatures are very delicate. Since they are made up of thousands of tiny scales, if one of them becomes damaged, the butterfly might not be able to fly. Underneath these scales are very thin layers of a material called chitin. This is the same substance that makes up your hair and fingernails. These chitin layers serve different purposes per butterfly.
The scales on the wings help insulate the insect as it flies, and increase airflow over the wings. They also help the creature soak up heat and dry out faster. Tiny changes in scale thickness can overall affect the body temperature of a butterfly.
Adult Lepidoptera insects usually have upper and lower membranes on their wings. Which are connected by tiny fibers and hollow ribs. These ribs are not veins. They can contain nerve fibers and tracheae along with blood vessels. The wings are controlled by rapid muscular contraction and expansion of the thorax.
The wing scales on these creatures are also translucent. However they get their color from the way they are configured across the butterfly. This inturn makes them reflect blue light. There can be up to two or more layers of scales scattered across the wings, and are stacked through microscopic arches and columns. When light hits these layers, the majority of light hits the upper layer, while the rest of the light is reflected inward.
It is important for the insects to display their colors as they need to display their warning colors to other predators.
Butterflies are translucent creatures. They often carry translucency through their wings, and this gives them several advantages.
It is rare to see on land creatures with this trait, and butterflies are one of only a few that exhibit it. A few studies suggest that translucency helps to hide them from predators and signal them not to eat them.
Nipam Patel, director of the Marine Biological Laboratory (MBL) has completed a several year study on this effect in butterflies, and reached some interesting conclusions. He and his various teams studied how this effect evolved over time, and how it benefits the biology of the creatures as a whole.
They noticed it as a main self defense mechanism that assisted in developing the warning colorations across the wings. They also noticed that butterflies share patterns between species. Some butterfly species are toxic, and this trait helps non toxic species blend in and confuse predators.
There is something called mimicry rings in the wings of these insects. These rings can overlap with translucent areas of the butterfly. Mimicry rings help showcase the butterfly’s color. They also found that butterfly wings do not have any glare coating, so on bright sunny days you can look right through them and see the mimicry rings. They hypothesize that the translucent makes the colors more visible when the creature is in direct view of predators. As well as more camouflage when the creature is in the shadows.
Their conclusions on how butterfly species evolved transparent wings was also a bit interesting. When comparing 123 Lepidoptera species together, they concluded that each species has evolved transparency independently.
There also have been studies on individual species of butterflies. Particularly the Monarch. The Monarch butterfly is a well known insect in North America. They are endangered, and so understanding their threats is very important. Monarchs migrate through each season in North America, and through this migration, we lose more and more monarchs per year.
Scientists have identified 5 major potential threats to the Monarch Butterfly through use of observational, experimental, and simulation models. The first main threat is change in suitable abiotic environmental conditions. The second is deforestation. Next, exposure to contaminants and bacteria. Finally, species specific pathogens and parasitism.
Insects overall are on the decline. Due to global warming, invasive species have invaded areas they shouldn’t have, and thrived on insect populations. Forestry has disappeared, and over all the Earth has heated up.The more insect populations disappear, the more of an extinction downstream effect will happen.
Conservation management of insects is equally important as other land animals. The more we study insects, the better we can understand which parts of their habitats are at risk.
The Monarch Butterfly for example, has certain areas along its migration route that are more dangerous than others. The areas in Mexico that it travels to during the winter are at higher risk than areas in Northern America. This is mainly due to rainforest deforestation. This means fewer and fewer monarchs make it back each year.
Butterflies are also declining all throughout Europe as well. In the United Kingdom 8% of the insect species have become extinct since 1976. Meanwhile in the Netherlands, 20% of insect species have become extinct. For Europe there is something called The Red List which currently helps catalog endangered species. As of 2010, Butterflies made up 38 of the 482 European species on the list. The decline of these animals in Europe is directly linked to climate change, chemical pollution and habitat loss.
Butterflies are important to us as they are one of the few insects that humans are not repulsed by. So commonly they are used by scientists to help explain how important insect species are to the international ecosystem. The overall decline in insects in recent years will mean disaster for every single animal on Earth. So any tool we can use to get that point across is important. Even if it's another animal.
Butterflies also react quickly to any change in their environment. So their disappearance is often the first warning sign to something larger. Currently, there are many studies happening across Europe to monitor these creatures per year and species. These studies have been ongoing for many decades.
One of the most studied butterflies in Indonesia has been the milkweed butterfly. These creatures are unusual as they tend to feed off of caterpillars from other butterflies, and drink them alive. These butterflies have tiny claws that they use to tear at their prey. Then they wait for the liquid to come out of the creature before consuming it. In turn, the caterpillars try to contort their bodies into a protective shape. However, this mostly never works. The species feeding off of them mostly is looking for the juices the caterpillar has consumed from plants. As often the plants consumed by caterpillars helps them produce pheromones to attract females. By consuming a caterpillar, a butterfly can double its pheromone amount. Studies documenting this have been published in the journal Ecology.
Most Milkweed butterflies are found in Asia. But four species of them live in North America. One being the Monarch butterfly. The Monarchs are not as aggressive as their counterparts. However, they will scratch at milkweed plants to try and digest the sap.
Butterflies have evolved in many different ways since they first appeared millions of years ago. One trait their ancestors had was that they did not feed on plants. After studying 70 fossils of wings and scales in Germany, scientists were able to analyze more details of ancient Lepidoptera, and reach these conclusions. The fossils they studied were over 200 million years old, and are some of the oldest evidence of insects on Earth. They found that a lot of the fossils shared traits with Moths rather than today's Butterflies. It is estimated that the first ever flowers started growing around 140 million years ago, Butterflies had to cope with other food sources for around 60 million years. The researchers estimated that these creatures fed off gymnosperms instead. These are large flowerless, seed producing plants. These gymnosperms contained sugary droplets that would give these insects energy.
These researchers also hypothesized that lepidopterans evolved to have sucking proboscis instead of teeth. Their idea is that The late Triassic was extremely hot, and in turn lepidopterans may have developed proboscis instead of mouths to control moisture loss.