Tiger swallowtail caterpillars are the larval stage of the beautiful tiger swallowtail butterfly. You might be wondering if these caterpillars are poisonous. The simple answer is no, tiger swallowtail caterpillars are not poisonous. However, they do have defense mechanisms to ward off predators.
One of the ways they protect themselves is by resembling bird droppings. This clever camouflage allows them to avoid becoming a meal for hungry predators. Additionally, when threatened, they can rear up and display a brightly colored, forked gland called the osmeterium. The osmeterium releases a foul-smelling chemical, deterring potential attackers.
Now that you know tiger swallowtail caterpillars aren’t poisonous, you can appreciate their unique adaptations and their contribution to the life cycle of the stunning tiger swallowtail butterfly.
Identifying the Tiger Swallowtail Caterpillar
The tiger swallowtail caterpillar can be easily identified by its distinct appearance. It is predominantly black and yellow, making it quite distinguishable from other caterpillars. Here are some features to help you recognize it:
- Black body with yellow markings
- Size varies, but it can grow up to 2 inches in length
When observing a tiger swallowtail caterpillar, you may notice its bright and contrasting colors. These caterpillars sport a combination of black and yellow stripes, which help them blend into their surroundings and avoid predators.
Keep in mind that the size of a tiger swallowtail caterpillar will vary as it grows. The younger ones may be smaller, but when fully grown, they can reach up to 2 inches in length. The distinct appearance of the tiger swallowtail caterpillar makes it easy for you to spot and appreciate its unique beauty.
Behavior and Defense Mechanisms
The tiger swallowtail caterpillar is known for its unique behavior and defense mechanisms. When you observe these creatures, you might notice how they often rely on their appearance as a primary mode of defense.
The caterpillar’s body features false eyes and colorful markings that make it look more intimidating to potential predators. In particular, these markings often resemble the eyes of a larger animal, deterring predators who might otherwise see the caterpillar as an easy meal.
Another defense mechanism employed by the tiger swallowtail caterpillar is its ability to produce a foul odor from specialized glands called osmeterium. When threatened, the caterpillar will extend these glands and release the unpleasant smell, repelling potential predators and keeping itself safe. You can learn more about this defense mechanism in this video about the black swallowtail caterpillar’s defense mechanism.
Here are a few key features of the tiger swallowtail caterpillar’s defense mechanisms:
- False eyes for intimidation
- Colorful markings that mimic larger animals
- Osmeterium glands that release a foul odor
These defense mechanisms, coupled with the caterpillar’s behavior of staying hidden and feeding on a variety of host plants, make the tiger swallowtail caterpillar a fascinating subject, illustrating the incredible adaptability of nature. Remember to always appreciate these tiny creatures from a distance, as their mechanisms are meant to help them survive in the wild.
Habitat and Distribution
The tiger swallowtail caterpillar can be found in various habitats across North America. You’ll mostly find them in the United States, Canada, and even parts of Mexico. They are quite adaptable, making their homes in regions such as woodlands, mountains, and wetlands.
For example, in woodlands, you may find these caterpillars on trees like aspens, birches, and willows, as mentioned on the Field Station website. They have a preference for host plants within the carrot family, which offer abundant food sources.
Comparing tiger swallowtail caterpillars to other species, they are quite flexible in their habitat preferences. In mountainous regions, you might see them at higher elevations where their host plants thrive. Wetlands also provide suitable habitats, thanks to an abundance of trees and vegetation.
To summarize the key habitats and distribution for the tiger swallowtail caterpillar:
- Habitat: Woodlands, mountains, and wetlands
- Range: United States, Canada, and parts of Mexico
- Host plants: Aspens, birches, willows, and plants in the carrot family
Remember to consider these factors when exploring North America and keep an eye out for these fascinating creatures in their natural environments.
Life Cycle of the Tiger Swallowtail Caterpillar
Tiger Swallowtail caterpillars go through an incredible transformation during their life cycle. Let’s take a brief look at each stage of their development:
Eggs: Female Tiger Swallowtails start by laying their eggs on the host plant, typically on the underside of leaves. These tiny, spherical eggs are pale green and will hatch in about 4-10 days.
Larva: Upon hatching, the caterpillars begin feeding on the leaves of their host plant. As they grow and molt, their appearance changes. Younger caterpillars resemble bird droppings, while older ones have green or brown bodies with blue eyespots. The caterpillar stage lasts for about 3-4 weeks. During this time, they feed voraciously to store enough energy for the next stage.
Pupa: Once they have reached their full size, the caterpillars form a chrysalis, entering the pupal stage. The chrysalis is typically brown or green, helping it blend in with the surrounding foliage. This stage lasts about 10-20 days, during which the caterpillar undergoes a remarkable transformation.
Adult Butterfly: Finally, the adult Tiger Swallowtail butterfly emerges from the chrysalis. These magnificent butterflies have broad, colorful wings with a wingspan of 3-6 inches. You can distinguish males from females by the wing coloration: males have yellow wings with black stripes, whereas females have either yellow or a dark blue-green, almost black, coloration.
The life cycle of the Tiger Swallowtail caterpillar generally occurs in the spring and fall. It’s important to remember that while the caterpillars can cause minor damage to host plants, they are not poisonous or harmful to humans. Enjoy observing these creatures as they grow and transform into beautiful butterflies!
Diet and Host Plants
The diet of tiger swallowtail caterpillars mainly consists of leaves from various host plants. Some examples include cherry, cottonwood, aspen, and willow trees. As caterpillars, they predominantly feed on leaves, but as adult butterflies, they shift their diet to nectar from flowers.
When it comes to host plants, tiger swallowtails are known for their versatility. Some common host plants they eat from are:
While feeding on leaves, tiger swallowtail caterpillars may also occasionally ingest small amounts of nearby vegetation, such as grass. However, it is important to note that these caterpillars are not harmful to the plants per se.
In adult form, tiger swallowtails feed on nectar from flowers in addition to the leaves they already consume. This varied diet allows them to thrive in different environments and adapt to changes in their habitat.
Remember to be cautious around tiger swallowtail caterpillars, as some people may mistakenly assume they are poisonous due to their bright color patterns. However, rest assured that they are harmless to humans and livestock. By understanding their diet and host plants, you can appreciate these beautiful creatures even more.
Interaction with Other Species
Tiger swallowtail caterpillars interact with several species in their ecosystem, which affects their survival rate and growth. Let’s take a brief look at these interactions.
Predators: Birds are the main predators of tiger swallowtail caterpillars1. Many birds, such as warblers and chickadees, feed on caterpillars as an important source of nutrition. Additionally, some snake species also prey on caterpillars, but these instances are relatively rare.
Ants: Ants can be both beneficial and harmful to tiger swallowtail caterpillars. In some cases, ants protect caterpillars from predators like birds2. However, ants may also attack tiger swallowtail caterpillars if they are seen as a source of food.
Here’s a table comparing the roles of some of the species in the tiger swallowtail caterpillar’s life:
|Birds||Predators||Warblers feeding on caterpillars|
|Ants||Protectors/Attackers||Ants protecting or attacking caterpillars|
|Snakes||Rare Predators||Snakes occasionally preying on caterpillars|
Pests: While it’s true that tiger swallowtail caterpillars can potentially defoliate host plants, they are not typically considered major pests.
In conclusion, your awareness of these interactions can help you better understand the complex relationships within the ecosystem that influence the life of the tiger swallowtail caterpillar.
- Eastern Tiger Swallowtail – US Forest Service
- Caterpillar and Moth Bites – StatPearls – NCBI Bookshelf
Potential Harm to Humans
Tiger swallowtail caterpillars might seem harmless to you, but it’s crucial to remember that they can pose certain risks. Specifically, these caterpillars don’t have a venomous sting like some other species; however, they do possess toxins in their bodies.
As a result, if you accidentally touch or handle a tiger swallowtail caterpillar, you might experience skin irritation. Generally, symptoms include itching and redness. To help alleviate the discomfort, make sure to wash the affected area with soap and water immediately.
While tiger swallowtail caterpillars are not considered dangerous, it’s always a good idea to be cautious when encountering them. To avoid any potential harm, make sure you admire these fascinating creatures from a safe distance.
Conserving the Tiger Swallowtail Caterpillar
Tiger Swallowtail caterpillars are essential to the lifecycles of various swallowtail butterfly species, such as the Eastern Tiger Swallowtail, Pipevine Swallowtail, Black Swallowtail, Spicebush Swallowtail, and Western Tiger Swallowtail. This section will guide you on how to conserve the caterpillars and support their role in sustaining butterfly populations.
In order to conserve Tiger Swallowtails, follow these steps:
- Plant host plants: Swallowtails caterpillars need specific plants to feed on. Your garden can include trees like aspens, birches, and willows which are known as food plants for the Canadian Swallowtail.
- Avoid pesticides: Limit the use of harmful chemicals in your garden. These substances may threaten the survival of swallowtail caterpillars and other beneficial insects.
- Create a diverse habitat: Including a variety of flowering plants and trees in your garden can attract different species of butterflies and boost biodiversity.
Tiger Swallowtails differ from other species like the Monarch Butterfly. Here’s a comparison table:
|Feature||Tiger Swallowtails||Monarch Butterfly|
|Host Plants||Aspens, Birches, Willows||Milkweed|
|Caterpillar Appearance||Bright green or brown||Black, yellow, and white stripes|
By maintaining a butterfly-friendly garden for Tiger Swallowtail caterpillars, you contribute to the conservation of these magnificent creatures and help maintain their vibrancy and importance within the ecosystem.
Myths and Misconceptions
Contrary to popular belief, tiger swallowtail caterpillars are not poisonous. While there are other species of caterpillars that are venomous, such as the pipevine swallowtail caterpillar, saddleback caterpillar, and io moth caterpillar, the tiger swallowtail caterpillar is harmless to humans and animals. Let’s look at some of the common myths and misconceptions surrounding these fascinating creatures.
One myth is that birds avoid eating tiger swallowtail caterpillars due to their bright colors and patterns. While it’s true that certain colors in nature tend to indicate poison or danger, this doesn’t apply to all organisms. Tiger swallowtail caterpillars have unique features, like false eyes and bird dropping-like patterns, which help them blend into their environment and discourage predators like birds. But these adaptations are all about camouflage and deterrence, not toxicity.
|Caterpillar Type||Poisonous to Humans?||Features|
|Tiger Swallowtail Caterpillar||No||False eyes, bird dropping-like patterns|
|Pipevine Swallowtail Caterpillar||Yes||Bright colors, dark markings|
|Saddleback Caterpillar||Yes||Stinging spines, bright colors|
|Io Moth Caterpillar||Yes||Stinging spines, bright colors|
Remember that not all bright and flashy caterpillars are dangerous. When you encounter a tiger swallowtail caterpillar, appreciate its fascinating characteristics, but know they won’t harm you or your loved ones. Remember to always exercise caution around unfamiliar creatures, and if you’re unsure, it’s best to keep a safe distance.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Tiger Swallowtail Caterpillar
Wed, Oct 8, 2008 at 6:21 PM
Today, I found this caterpillar on my driveway underneath a Hickory tree. It is about 1 1/2 inches long, light brown, purple dots and two, yellow, “eye-like” dots on its body behind its head. When I carefully picked it up, I must have startled it and a strange yellow, forked tongue(?) came to its defense along with a strange odor. I’ve seen many insect defense mechanisms but none quite like this. Anyway, I live in Sussex County, New Jersey (northwest) and have never seen a caterpillar like this. Looking at your photos it appears to be a swallowtail of some type. Can you identify for sure? Thanks!
Northwest NJ, Sussex County
This is most likely an Eastern Tiger Swallowtail Caterpillar, but you are also within the range of the Canadian Tiger Swallowtail. This typically green caterpillar changes color to brown or occasionally orange just before pupation. The scent gland you mentioned is characteristic of the swallowtails and is known as the osmetrium.
Letter 2 – Tiger Swallowtail Caterpillar
Location: Sudbury, Ontario, Canada
September 29, 2010 5:24 am
Can you please identify this ”bug”? I noticed this guy on my fathers deck about a 5 weeks ago. He is about as big as your thumb, and was waving his ”head” about when first noticed.
This is the Caterpillar of a Tiger Swallowtail, though we cannot say for certain if it is a Canadian Tiger Swallowtail, Papilio canadensis, which is well documented on BugGuide, or the Eastern Tiger Swallowtail, Papilio glaucus, also depicted on BugGuide, as the ranges of the two species overlap and they look quite similar. Both species have green caterpillars that turn orange or brown and leave the trees where they have been feeding as they prepare to pupate.
Letter 3 – Tiger Swallowtail Caterpillar
found a sweet bug
Location: western pennsylvania
March 16, 2012 10:28 pm
I found this little fella while camping. Looks awesome. I was suprised at my phones picture quality. This could be a common insect but I have never seen anything like it. I sorta examined it with a small stick and it had antenna like objects that protruded from the head at my stick. Left a pungent odor on the stick. I like the markings that look like eyes even though that’s not the head.
We understand your weather is unseasonably warm, but we still suspect this prepupal Tiger Swallowtail Caterpillar is not a recent sighting. The antennae you describe is a scent organ called an osmeterium.
Letter 4 – Tiger Swallowtail Caterpillar
what type of caterpillar
December 27, 2010 7:22 pm
We saw this caterpillar hiking in Vermont this fall and we are wondering what it is and what it will look like as a butterfly or moth.
Signature: interested in amesbury
Your caterpillar is one of the Tiger Swallowtails. There are several species with ranges that overlap in Vermont, including the Eastern Tiger Swallowtail and the Canadian Tiger Swallowtail. It is very difficult to tell the species apart. The caterpillars of both species turn from green to brown or sometime orange just prior to pupation. You can see a photo of an adult Tiger Swallowtail in our archive.
Letter 5 – Tiger Swallowtail Caterpillar
I found this on my deck. Can you tell me what it is? I have attached a couple of pictures.
It is the caterpillar of a Tiger Swallowtail, Papilio glaucus. This is a large, graceful yellow and black striped butterfly. The caterpillar is fond of wild cherry and other trees. Those false eyes are meant to scare hungry birds into thinking the benign caterpillar is a ferocious snake.
Letter 6 – Tiger Swallowtail Caterpillar
a beautifully colored grub
Well, we found this is a heating duct at Flathead Lake, Montana. Can you identify this “grub”? Thanks
Beautiful Tiger Swallowtail Caterpillar image. Your photo shows the Osmeterium. The Osmeterium is a Y-shaped gland located behind the head of some caterpillars which can be pushed out to emit a chemical disagreeable to potential predators. Your caterpillar will eventually metamorphose into a large beautiful black and yellow striped butterfly. The Tiger Swallowtail is the official state insect of Virginia and Georgia. The official butterfly of South Carolina and the state mascot and official butterfly of Alabama.
Letter 7 – Tiger Swallowtail Caterpillar
snail type bug
July 12, 2009
Can you tell us what this is? Is it a worm; snail; what???
Union county bug finder
Union County, PA
Dear bug finder,
You have found the caterpillar of a Tiger Swallowtail, Papilio glaucus. BugGuide has an image of this typically green caterpillar with the same coloration as yours, and there is a comment that judging by the color, it is ready to pupate. BugGuide also indicates: “Caterpillars feed on Sweet Bay (Magnolia virginiana), Black Cherry (Prunus serotina), Swamp Bay(Persea palustris) and Tuliptree (Liriodendron tulipifera). Adults take nectar from a variety of flowers.” The adult butterfly is typically a large showing yellow tailed butterfly with black stripes, though there are some dark females.
Letter 8 – Tiger Swallowtail Caterpillar
Caterpillar with “eyes.”
June 27, 2010
From what I’ve found on your site, I think this caterpillar may be related to the Tersa Sphinx Moth. However, the one that I found didn’t have a horn. Is it a different species in the same family? It was found crawling on a wall in Shreveport, Louisiana on May 28th, 2010.
There are many caterpillars that have protective coloration that includes eyespots. This is not a Sphinx Caterpillar, but rather a Swallowtail Butterfly Caterpillar, most likely the Eastern Tiger Swallowtail which is pictured on BugGuide.
Letter 9 – Tiger Swallowtail Caterpillar
Location: Southern Lancaster County, PA
July 28, 2011 10:22 pm
We took this photo on a camping trip in the river hills of southern Lancaster County, Pennsylvania In mid July this year. We were close to a tree line and it was walking on the ground. It was so strange. I never saw a bug like this before… I was wondering if you can identify it??
This is the caterpillar of a Tiger Swallowtail, and its orange osmetrium, a scent organ, is just beginning to emerge.
Letter 10 – Tiger Swallowtail Caterpillar
Subject: What’s this Bug?
Location: Torbay, Newfoundland, Canada
October 4, 2012 8:29 pm
I grew up in Newfoundland, as has my entire family….. none of us has ever seen this bug before. It’s about 4” long and literally reared up at me when I touched it! The forked prong came out of it’s mouth at that time. Weird!
This is a pre-pupal Tiger Swallowtail Caterpillar, and considering your location, it is most likely a Canadian Tiger Swallowtail, Papilio canadensis. The “forked prong” you described and photographed is a defense organ known as an osmeterium. The Osmeterium releases an odor that some predators find offensive and it might also give the caterpillar the appearance of a snake that may discourage getting eaten by a bird.
Letter 11 – Tiger Swallowtail Caterpillar
Subject: slug bug
Location: Montclair NJ
January 22, 2014 1:13 pm
Hi – This bug was spotted in the suburbs of Montclair, NJ on a grassy curb.
July 19, 2012
Can you help identify it …?
Signature: A Borns
Dear A Borns,
This is the caterpillar of an Eastern Tiger Swallowtail or a closely related species. The beetle on the right is some species of Scarab.
Letter 12 – Tiger Swallowtail Caterpillar
Location: Vernon, BC
September 13, 2014 4:43 pm
My boys and I found a Catterpillar. We can’t find what kind it is.
Early September in Vernon, BC Canada.
This is one of the Tiger Swallowtail Caterpillars, and based on your location, our best guesses are either a Pale Tiger Swallowtail Caterpillar (see image on BugGuide) or a Western Tiger Swallowtail (see Bugguide for image). The orange coloration indicates that this individual is nearing the time to metamorphose into a chrysalis.
Letter 13 – Tiger Swallowtail Caterpillar
Subject: Some sort of catterpillar?
Location: Central New York
September 21, 2014 10:31 pm
Summertime in central new york. No idea what this bug is
Signature: Mac F
Dear Mac F,
This is the caterpillar of a Tiger Swallowtail. Recent taxonomy has resulted in the classification of several different species based on the range, and several different species, including the Eastern Tiger Swallowtail and the Canadian Tiger Swallowtail have ranges that overlap in your vicinity.
Letter 14 – Tiger Swallowtail Caterpillar
Subject: Large caterpillar
Location: Natural Bridge, VA
June 10, 2015 4:23 pm
Hi – saw this guy crossing our path today. Any idea what it is? Thanks in anticipation.