Butterflies, members of the superfamily of species known as “Papilonoidea,” are small, flying insects. An old group of insects, there are butterfly fossils that date back to the Paleocene period, some 56 million years ago.
The typical moth goes through a four-stage life cycle, part of which is the much-romanticized metamorphosis from caterpillar to butterfly. They are like moths and are known for their large variation of colors and patterns. Some butterflies even make use of camouflage and mimicry of their surroundings to conceal themselves from predators.
They sometimes fall victim to a range of small animals that consider them a food source, but what do butterflies eat? Let’s explore the interesting diet of these majestic creatures.
Butterfly Eating Patterns (What Do Butterflies Eat?)
The first thing to note is that due to their unique life cycle, butterflies have a different diet when they are in their caterpillar stage and their adult stage.
As caterpillars, they are herbivores. They consume plant matter to support their growth into their adult butterfly stage. They have powerful jaws and mouths that enable them to chomp down on leaves from many kinds of plants.
This includes herbaceous plants (known commonly as forbs). This category of plant life refers to any low-growing plants that bear seeds to propagate (basically, anything that isn’t grass or a tree). Caterpillars, for their part, like to feast on violets, clovers, dandelions, nettles, sunflowers, burdock, and other varieties of wild plants. In a garden, they will go for favorites like spinach, cabbage, and similar kinds of greens and garden herbs.
Their diet is not limited to these kinds of plants, though. Though they prefer broad-leafed plants, they will also go after grains and grasses. They may choose to consume wild grass or go for the leaves of grains like corn and barley.
Caterpillars prefer sticking close to the ground in many cases, but in situations where they must, say if food is scarce or they are born somewhere without plentiful pastures, they will take to the trees. Here, they go for tree leaves. They prefer things like maple, elm, birch, and the like. Only in the direst circumstances will most caterpillar species go for fruit trees and “landscaping plants,” but if they must do it to survive, they will.
This overview, of course, is a generalization, and some particulars of caterpillar diets will vary from species to species. Viceroy caterpillars, for instance, will go for some fruit tree varieties, particularly apple and cherry. Mourning Cloak caterpillars, on the other hand, will stick to elm, poplar, and willows for their diet. You can find a more complete listing of the variation between caterpillar species here.
Note that these caterpillars prefer their “host plants” as they need these to obtain the proper nutrients to thrive. In some cases, caterpillars won’t eat if they don’t have access to their preferred plants, and that the plants they normally much on might even vary from region to region.
For the time that they are in their caterpillar form, most butterflies must eat as much as they can to induce their metamorphosis. Sometimes this might be a few short months, and in other cases, the caterpillar phase can last for years. Their diet may also confer additional benefits while they are in their caterpillar stage.
For example, Monarch caterpillars like to eat milkweed. In addition to tasting awful, milkweed contains a toxin that the caterpillars can use to protect themselves. Many predators will avoid Monarch caterpillars because ingesting them will cause a whole range of negative effects. Wooly Bear caterpillars employ a similar method, absorbing the chemicals from the leaves they eat to make themselves taste bad and thus unappealing to potential predators.
Caterpillars do need water to survive but don’t imbibe it the way humans would. Instead, they rely on the leaves they eat, absorbing the water from those.
Curiously, there are a few species of caterpillar that are predatory. Instead of ingesting leaves, these caterpillars, like the Apefly caterpillar, will hunt down scale insects. Others, like the Moth Butterfly caterpillar, will go after ant larvae.
Though many caterpillars are known as notoriously picky eaters, only able to survive on their host plants, there are certain cases in which unconventional food sources can sustain them. This article notes several cases where pumpkins and cucumbers were used to nourish caterpillars with great success. There’s just one caveat:
These alternatives have been utilized by many people in the past. They only seem to work for fifth instar larvae that are less than four days from pupating. Many of the larvae will not make these transitions successfully.”
In other words, it can work, but only at a particular stage in the caterpillar’s life, and even then, not always the way you might intend.
Once the process of metamorphosis is complete, the caterpillar changes into a beautiful butterfly. With this change in appearance comes a change in their anatomy, and by extension, their diet. As butterflies, they no longer “eat” in the traditional sense. Instead, they take to absorbing their nutrients in liquid form. Using their long mouth-tube, called a proboscis, the suck the liquids from plants, flowers, and other food sources.
Chief among these sources is the nectar from flowers. It is not uncommon to see groups of butterflies amassing in fields of flowers to feast one their moist innards. Flowers aren’t the only source of food for these insects, though. Butterflies can also gain nutrients from tree sap, pollen, fruit, feces, and sweat.
This is the reason that butterflies may sometimes land on people, to absorb the sodium contained in their bodily excretions. Getting enough salt is of importance, as sodium, along with a few other choice minerals, are vital to their reproductive cycle.
An interesting fact is that butterflies use their feet to sense and taste. They can use this ability to land upon flowers and other potential food sources and determine if they are worthwhile.
Creating A Butterfly Habitat
If you would like to attract butterflies to your property or raise some of your own, you’re going to need a garden with the appropriate host plants. The listing we mentioned earlier is a good place to start, but you might need some more detailed information to track down the right plants for a specific species. If this is the case, you can refer to this database of Lepidopteran host plants, which allows you to search by family, genus, and species.
You might also try growing different species of fruit or installing butterfly feeders nearby. You can find some that mimic the appearance of a flower to make them more appealing to the butterfly and fill them with a mixture of sugar and water to feed any butterflies that may come around in search of food.
In addition to food, you might also try including a few things in your butterfly garden that can make life easier for them. Butterfly boxes don’t really work, but you could try including some dark-colored rocks for them to rest on and absorb heat. Additionally, your whole garden should be in an area that is sunny and warm, as butterflies need to maintain their body temperature of 80-100 degrees for optimal functioning.
You should also take care to avoid some of the things that can kill butterflies in their caterpillar stage. The biggest offender is pesticide. Avoid purchasing any plants for your garden that have been treated with pesticides, and always check with the nursery you buy from in advance if they have used pesticides on any of the plants.
Even flea and tick medication used on pets can be a danger. If you have dogs are cats you treat with stuff like Frontline, keep them out of the garden. Don’t handle plants in your garden after you’ve given your pet an application of these medicines. Wash your hands first.
If you want to raise caterpillars on your own and release them into the wild once the metamorphose, you can use a small tank to house them. Make sure there are a few air holes in the top, and paper lining the bottom so you can clean up the frass and molted exoskeletons they leave behind easily. Feed them daily with leaves from their preferred host plant, then watch them flourish.
Butterflies are beautiful insects that, while short lived, are a delight to view because of their brilliant color schemes. Butterflies have a four-stage life cycle. They start as eggs, progress to caterpillars, grow larger, enter a cocoon for a period, then emerge in their final form. Their diet changes as the progress from a caterpillar to a butterfly.
As caterpillars, they will feast upon the leaves of various plant species. These can vary based on the specific butterfly type, but will normally include the leaves from trees like maples, flowers such as violets, and several kinds of wild grains. As butterflies, they no longer require a diet of leaves and instead switch to liquid nutrition from plant nectar, tree sap, and human sweat.
Butterflies make a great addition to home gardens. If you’d like to learn more about these insects, you can start by getting yourself acquainted with more of their habits, courtesy of this article from the San Diego Zoo, or by checking out The Butterfly Website, a large collection of information on everything butterfly.