Black Swallowtail vs Tiger Swallowtail: Decoding the Differences

Black swallowtails and tiger swallowtails are two beautiful species of butterflies that are known for their vibrant colors and distinct patterns. Both are large and impressive insects commonly found in fields, meadows, and sunny backyards. As with most species, males and females have slight variations in size and appearance. For instance, female black swallowtails can have a wingspan of 3¼ to 4¼ inches and often showcase more color variations than the males.

While both species share some similarities, they also have unique features that distinguish them from one another. Black swallowtails have yellow, blue, orange, and red colors on their wings, whereas tiger swallowtails have a more yellow-based pattern. Moreover, black swallowtails have yellow spots on their bodies, whereas tiger swallowtails have a yellow streak along each side of the thorax and abdomen. Understanding these differences not only aids in their identification but also helps us appreciate the diversity of the natural world.

Black Swallowtail vs Tiger Swallowtail: Overview

Characteristics of Black Swallowtail

The Black Swallowtail (Papilio polyxenes) is a butterfly species found in various open areas such as fields, meadows, parks, wetlands, prairies, and sunny backyards. Some key features include:

  • Adult females tend to be larger than males, with wingspans of 3¼ to 4¼ inches.
  • Wings are mainly black with yellow, blue, orange, and red markings.
  • Males have more noticeable yellow markings and less blue on their wings than females. Reference

Characteristics of Tiger Swallowtail

Comparatively, the Tiger Swallowtail is another species of swallowtail butterfly with its own unique traits:

Comparison Table

Feature Black Swallowtail Tiger Swallowtail
Size Females have a wingspan of 3¼ to 4¼ inches. Larger than Black Swallowtails.
Markings Black with yellow, blue, orange, and red. Yellow with black stripes resembling a tiger.
Habitat Fields, meadows, parks, wetlands, prairies. Forest edges, rivers, and wooded areas.

In summary, both Black Swallowtail and Tiger Swallowtail butterflies are types of swallowtail butterflies with distinct characteristics. While they share similarities in habitat preferences, they have different color markings and sizes.

Appearance and Identification

Wingspan and Size

  • Black Swallowtail: Wingspan 2½ – 3½ inches (6.7 – 8.9 cm)
  • Tiger Swallowtail: Larger, typically wingspan around 4 inches

Black Swallowtails and Tiger Swallowtails are large butterflies with noticeable differences in size and markings.

Color Patterns and Markings

Black Swallowtail

  • Predominantly black with colorful markings
  • Yellow round spots on the body
  • Males have a band of bright yellow spots across upperside wings
  • Females have less yellow and may lack the heavy yellow band1

Tiger Swallowtail

  • Comes in two morphs: yellow and black
  • Yellow morph has black stripes, resembling a tiger’s pattern
  • Black morph has less prominent markings, but still has yellow streaks on each side of the thorax and abdomen2

Sexual Dimorphism

In both Black and Tiger Swallowtails, females are generally larger than males:

Black Swallowtail Tiger Swallowtail
Males Smaller; more yellow on wings; bright yellow spots on upperside wings3 Smaller; yellow morph with black stripes or black morph
Females Larger; less yellow; blue wash above tails4 Larger; black morph with less prominent markings; still have yellow streaks5

Distribution and Habitat

Range in North America

  • Black Swallowtail: Found in open areas across North America, including the United States, Canada, and Mexico.
  • Eastern Tiger Swallowtail: Common in the eastern parts of the United States and present east of the Mississippi River. Also found in several Mexican states.
  • Western Tiger Swallowtail: Primarily distributed in the western parts of the United States and Canada.
  • Canadian Tiger Swallowtail: Widespread in Canada and the northern United States.

Habitat Preferences

Black swallowtails and tiger swallowtails share some habitat preferences:

  • Open Areas: Both species are found in open areas such as fields, meadows, parks, wetlands, and prairies.
  • Sunny Backyards: Home gardens that get ample sunlight attract both black and tiger swallowtails.
  • Forest Edges: Tiger swallowtails, especially eastern and western species, prefer habitats near forest edges.
Black Swallowtail Eastern Tiger Swallowtail Western Tiger Swallowtail Canadian Tiger Swallowtail
North America United States, United States, United States, United States,
Canada, Mexico Canada, Mexico Canada Canada
Habitats – Open areas – Open areas – Open areas – Open areas
– Sunny backyards – Sunny backyards – Sunny backyards – Sunny backyards
– Forest edges – Forest edges – Forest edges+

Note: “+” indicates it’s more common for Canadian Tiger Swallowtail compared to other species.

In summary, black swallowtails and tiger swallowtails have overlapping ranges in North America, with habitat preferences that include open areas, sunny backyards, and forest edges. Each species has slightly different distribution patterns throughout the United States, Canada, and Mexico.

Life Cycle and Reproduction

Eggs and Caterpillars

Both Black swallowtail and Tiger swallowtail butterflies lay their eggs on host plants. Black swallowtail eggs are yellow and spherical, while Tiger swallowtail eggs are green. The caterpillars of both species go through various instar stages as they grow.

  • Black swallowtail caterpillars:

    • Green with black bands on each segment containing yellow-orange spots
    • Host plants include parsley, dill, and fennel
  • Tiger swallowtail caterpillars:

    • Green, camouflaged to resemble bird droppings in early instars
    • Older instars become green with two large, black and yellow false eyes
    • Host plants include wild cherry, tulip tree, and birch

Pupa and Chrysalis

As they transition to adulthood, both species form chrysalises. Black swallowtail chrysalises can be brown with dark striations or green. Tiger swallowtail chrysalises are typically brown or green, with some individuals blending into tree bark.

Adult Butterflies

Adult Black and Tiger swallowtail butterflies show sexual dimorphism.

  • Black swallowtail adults:

    • Males have more yellow and less blue on the wings
    • Females are larger, with a wingspan of 3¼ to 4¼ inches
  • Tiger swallowtail adults:

    • Males have bold yellow and black striped wings
    • Females come in two forms, yellow or black morphs, displaying different color patterns

Seasonal Broods

Black swallowtail butterflies have 3 or more generations per year, with eggs laid singly on host leaves or flowers. Male Black swallowtails often appear in late April and early May.

Tiger swallowtail butterflies have two to three broods per year. First brood adults emerge in the spring, followed by subsequent broods in the summer and sometimes fall.

Comparison table:

Feature Black Swallowtail Tiger Swallowtail
Egg color Yellow Green
Caterpillar appearance Green with black bands and yellow-orange spots Green, bird dropping-like (early instars), green with false eyes (older instars)
Chrysalis color Brown with dark striations or green Brown or green
Adult dimorphism Males have more yellow, females larger Males have yellow-black stripes, females have yellow or black morphs
Seasonal broods 3 or more per year 2 to 3 per year

Feeding and Host Plants

Caterpillar Host Plants

Black swallowtails and tiger swallowtails have different preferences when it comes to their caterpillar host plants.

Black Swallowtail Caterpillars:

  • Common host plants include wild cherry, anise, and parsley
  • Also known as “Parsley Swallowtail” due to the association with parsley

Tiger Swallowtail Caterpillars:

  • Common host plants are tulip trees, aspens, poplars, wild black cherry, ash, and willow
  • Eastern Tiger Swallowtails prefer spicebush, cottonwood, and sweet bay magnolia
  • Western Tiger Swallowtails favor cottonwoods, aspens, and other trees
Host Plant Preferences Black Swallowtail Tiger Swallowtail
Trees Wild cherry Tulip trees, aspens, poplars, ash, willow
Other Plants Anise, parsley Spicebush, sweet bay magnolia

Adult Butterfly Nectar Sources

When it comes to nectar sources, both black swallowtails and tiger swallowtails enjoy a variety of flowers. They mostly prefer flowers with strong scents and bright colors.

Black Swallowtail Nectar Sources:

Tiger Swallowtail Nectar Sources:

Both butterflies play a crucial role in pollination, and their feeding habits contribute significantly to their local ecosystems. Providing a diverse range of host plants and nectar sources in your garden can help support these important pollinators.

Protection and Defense Mechanisms

Caterpillar Defense Mechanisms

Both the Black Swallowtail and Tiger Swallowtail caterpillars have unique defense mechanisms to protect themselves from predators.

  • Black Swallowtail caterpillars

    • Resemble bird droppings in their earlier stages, making them less appealing to predators. In later instars, they develop a colorful pattern and possess an osmeterium, an Y-shaped, fleshy scent gland that releases a foul odor when threatened1.
    • Green eggs serve as camouflage on the host plant and help deter predators2.
  • Tiger Swallowtail caterpillars

    • Also resemble bird droppings in the early stages, which discourages predators3. As they age, tiger swallowtail caterpillars develop an eye pattern that deter potential threats by appearing as larger, more dangerous organisms.

Comparison: Black Swallowtail and Tiger Swallowtail Caterpillar Defense

Feature Black Swallowtail Tiger Swallowtail
Early Stage Appearance Bird droppings Bird droppings
Later Stage Appearance Colorful pattern, osmeterium Eye pattern
Egg Color Green N/A

Adult Butterfly Defense Mechanisms

When comparing the Black Swallowtail and Tiger Swallowtail adult butterflies defense mechanisms, a few noteworthy points stand out.

  • Black Swallowtails usually have a wingspan that ranges from 2½ – 3½ inches, with black wings displaying a yellow band and colorful spots, which can confuse predators and ward them off4.

  • Tiger Swallowtails are dimorphic, which means they have two distinct color forms, with the various colors and patterns acting as a camouflage, allowing them to blend into their surroundings5. Additionally, swallowtail butterflies are known for their classic tail-shaped extensions on their hindwings, which can imitate antennae and confuse predators about the butterfly’s orientation.

Other Swallowtail Species

Spicebush Swallowtail

The Spicebush Swallowtail (Papilio troilus) is part of the Papilionidae family and is often found in wooded areas. Males and females have distinct markings:

  • Males: Black wings with blue iridescence
  • Females: Black wings with blue and white spots

This species has a wingspan of approximately 3 to 4 inches and mainly feeds on spicebush plants.

Pipevine Swallowtail

The Pipevine Swallowtail (Battus philenor) is another member of the Papilionidae family. The males and females have similar coloration, but the females are slightly larger:

  • Both: Black wings with visible blue iridescence
  • Size: Females have a wingspan of 3.5 to 5 inches, males around 2.8 to 4 inches

This species feeds on pipevine plants, which makes them toxic to predators.

Giant Swallowtail

The Giant Swallowtail (Papilio cresphontes) is the largest swallowtail in North America with a wingspan ranging from 4 to 6 inches. They have striking black and yellow wing patterns:

  • Wings: Black with bands of yellow
  • Tails: Black with blue spots

The Giant Swallowtail is primarily found in gardens and citrus groves.

Two-Tailed Swallowtail

The Two-Tailed Swallowtail (Papilio multicaudata) is unique in having two tails instead of one on each hind wing. This species also features distinctive coloration:

  • Wings: Yellow with black stripes
  • Tails: Black with blue spots

These butterflies have a wingspan of 3.5 to 5.5 inches and are often found in open woodlands and riparian areas.

Comparison Table:

Species Wingspan Range Wing Coloration Tails Preferred Habitat
Spicebush Swallowtail 3-4 inches M: Black & blue; F: Black, blue & white spots Blue edges Wooded areas
Pipevine Swallowtail M: 2.8-4 inches; F: 3.5-5 inches Black & blue iridescence Blue edges Pipevine plants
Giant Swallowtail 4-6 inches Black & yellow bands Black & blue spots Gardens, citrus groves
Two-Tailed Swallowtail 3.5-5.5 inches Yellow & black stripes Double black & blue tails Open woodlands, riparian areas

Threats and Predators

Common Predators

Black Swallowtail and Tiger Swallowtail butterflies face threats from various predators, like birds and insects. Birds, such as swallows and sparrows, feed on the butterflies, while insects like spiders and praying mantises prey on them as well. Additionally, small mammals and other insects may feed on their eggs, larvae or pupae.

Threats and Conservation Efforts

Habitat loss is a significant threat to both Black Swallowtails and Tiger Swallowtails. Human activities, such as urbanization and deforestation, lead to shrinking habitats and reduced host plants for these butterflies. Pesticides used in agriculture and gardens also negatively affect the butterflies, as they can be toxic to them and their caterpillars.

Conservation efforts include:

  • Planting native host plants and nectar sources for caterpillars and adult butterflies
  • Reducing pesticide use to minimize harm
  • Encouraging habitat restoration in areas affected by human development
Threats Black Swallowtail Tiger Swallowtail
Birds Yes Yes
Insects (spiders, praying mantis) Yes Yes
Habitat loss Yes Yes
Pesticides Yes Yes

In summary, both Black Swallowtails and Tiger Swallowtails face similar threats and predators, such as birds, insects, habitat loss, and pesticides. Conservation efforts are vital for protecting these species and ensuring their continued survival.

Tips for Identifying Swallowtail Butterflies

Identification Chart

An identification chart can help you differentiate between black swallowtail and tiger swallowtail butterflies. Here’s a comparison table of their features:

Feature Black Swallowtail (Papilio polyxenes) Tiger Swallowtail (Papilio glaucus & Papilio canadensis)
Males More noticeable yellow and less blue on wings Yellow with dark tiger-like stripes
Females Larger, lacks yellow on wings, blue wash above the tails Yellow or dark forms with blue wash above the “tails”
Wing size 3¼ to 4¼ inches 3 to 6 inches
Hind Wings Iridescent blue Iridescent blue

Common Swallowtail Butterflies at Home

Both black swallowtail and tiger swallowtail butterflies are commonly found in open areas like fields, meadows, and gardens. Let’s take a look at their characteristics:

  • Black Swallowtail (Papilio polyxenes)

    • Males usually appear in late April to early May.
    • Yellow spots on the body.
  • Tiger Swallowtail (Papilio glaucus & Papilio canadensis)

    • Both morphs have yellow streaks along each side of the thorax and abdomen.
    • More common in forests and woodland edges.

Caterpillars of both species have distinct looks during the egg stage:

  • Black Swallowtail: Eggs are spherical, pale yellow to orangish, laid singly on host plants.
  • Tiger Swallowtail: Eggs are round, greenish-yellow, laid singly on the leaves of host trees.

By comparing these features, you can confidently identify black swallowtail and tiger swallowtail butterflies in your home and surroundings.

Miscellaneous Swallowtail Information

In this section, we will cover various topics related to black swallowtails and tiger swallowtails, including their physical adaptations, interaction with humans, and scientific classification.

Physical Adaptations

Black swallowtails and tiger swallowtails are beautiful butterflies with similar appearances. Here’s a comparison of their physical features:

Feature Black Swallowtail Tiger Swallowtail
Color Predominantly black Yellow with black stripes "or" mostly black (dark morph)
Wingspan 2½ – 3½ inches 3½ – 4½ inches
Yellow Spots Band across wings Long streak on sides of thorax and abdomen
Blue Wash Above tails Only present in dark female morph

Both species also have long, tubular proboscises for feeding on nectar from flowers. As caterpillars, black swallowtails often have a pale green color, which helps them blend in with leaves.

Interaction with Humans

Black swallowtails and tiger swallowtails can be found in various habitats, such as forests, meadows, parks, and gardens. Both species are drawn to areas with abundant flowering plants, including human-planted gardens. Males of both species have been known to extract sodium from mud puddles, which they require in their diets.

Scientific Classification

Here is the scientific classification for each species:

  • Black Swallowtail:

    • Kingdom: Animalia
    • Phylum: Arthropoda
    • Class: Insecta
    • Order: Lepidoptera
    • Family: Papilionidae
    • Genus: Papilio
    • Species: P. polyxenes
  • Tiger Swallowtail:

    • Kingdom: Animalia
    • Phylum: Arthropoda
    • Class: Insecta
    • Order: Lepidoptera
    • Family: Papilionidae
    • Genus: Papilio
    • Species: P. glaucus

Although the two species have distinct appearances, they sometimes interbreed, resulting in hybrids. These hybrids can display characteristics of both parent species. Pheromones play a crucial role in attracting mates, with male butterflies detecting female pheromones from a distance to locate them.

Overall, black swallowtails and tiger swallowtails have distinct physical adaptations, interact with human environments, and follow a similar taxonomy. In summary, these interesting butterflies demonstrate intriguing aspects of the natural world and can be an exciting sight for nature lovers.

Footnotes

  1. Black Swallowtail – Alabama Butterfly Atlas 2

  2. Field Station – Black and Tiger Swallowtails 2

  3. Black Swallowtail – Alabama Butterfly Atlas 2

  4. Field Station – Black and Tiger Swallowtails 2

  5. Field Station – Black and Tiger Swallowtails 2

Reader Emails

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 Hermaphrodite

 

Tiger Swallowtail Gynandromorph
Location:  Hillsborough, NC
August 6, 2010 10:48 am
Hi guys,
I work at the Butterfly House at the NC Museum of Life & Science, Durham, NC. Your site is invaluable to us! A friend of ours, who lives locally, sent us this photo of a Tiger Swallowtail gynandromorph, taken last week. I’ve been hoping to see one for decades! If you look closely you can see small patches of wing from male tissue on the female (left) side. What we’d like to know is, does anyone have an idea of the frequency of such an occurrence, especially a near-perfect bilateral one like this?
Richard Stickney

Tiger Swallowtail Gyandromorph

Hi Richard,
Your letter and photograph have us very excited.  On a recent behind the scenes tour our staff was given at the Natural History Museum of Los Angeles, the entomologist, Dr. Brian Brown was very proud of two specimens of butterfly gynandromorphs he showed us, but neither was as spectacular as this Tiger Swallowtail.  Its coloration is even more dramatic since the female left half is also the less common dark morph.  We will contact Dr. Brown to see if he can provide any information on the frequency of occurrence of gynandromorphs in general, and in particular, such dramatic examples.  We are going to have to bump something from our feature section to include this marvelous documentation.  Mom who is visiting from Ohio identified the food plant as Joe Pye Weed, a common roadside wild flower.

Tiger Swallowtails, including rare Gynandromorph, and Ailanthus Webworm Moths nectaring on Joe Pye Weed

Update:  Julian Donahue suggests some resources
August 9, 2010
That is indeed a dramatic bilateral gynandromorph.
I don’t know of a single paper that answers your question about the frequency of this, but you might want to ask someone who works in butterfly genetics.
Try sending the photo and question to some of the following, all of whom work in this field (all are Ph.D.s):
Andy Brower
Thomas C. Emmel [head of the McGuire Center in Gainesville, which probably has a large collection of gynandromorphs)]
Paul Opler
Austin “Bob” Platt
Mark Scriber [“expert” on P. glaucus]
Good luck,
Julian P. Donahue

Ed. Note: What follows is the email we sent to the experts.
Dear Venerable Experts,
I was given your names and contact information by my friend and neighbor Julian Donahue.  My name is Daniel and I am a rank amateur who has been running the pop culture website What’s That Bug? on the internet for ten years.  This amazing photograph of a bilateral gynandromorph Tiger Swallowtail was recently sent to the website from North Carolina.  Can anyone provide any information on the degree of frequency of butterfly gynandromorphs and any information on their fecundity?  Thanks for your assistance.
Daniel Marlos

Paul Opler responds
Dear Daniel,
This is not only a bilateral gynandromorph, but is also showing some mosaic traits.
Beautiful image!
Paul Opler

Professor Andrew Brower responds
Hi Daniel,
You asked about fecundity of these:  I think zero – the genitalia are half male, half female, and I think they cannot engage in copulation.
I don’t know offhand the frequency with which bilateral gynandromorphs occur, but I know by their desirability that they must be rare – perhaps one in 10,000 (a random guess).
Andy Brower
Professor Andrew Brower
Department of Biology
Middle Tennessee State University
Murfreesboro, TN  37132   USA

Mark Scriber responds
Hi everyone;
This is a beautifual specimen. It is obviously nearly a bilateral gynandromorph, but with yellow mosaic color (probably male-like). We sometimes see yellow/dark mosaics (usually in the dark morph female wing background) in offspring our reared tiger swallowtials. I would estimate that these have occurred roughly at rates of 1  in 4,000-5000 offspring. The bilateral gynandromorph tigers are rarer, and might be found roughly once in 20, 000.  We have reviewed the role of hybridization in this phenomenon and some of the historical records in a recent paper:
Scriber, J. M.,  R.J. Mercader, H. Romack and M. Deering. 2009 Not all bilateral gynandromorphs are interspecific
hybrids: new Papilio specimens from field populations. J. Lepid. Soc. (color illustrated) 63 (1): 37-47
Best regards,
Mark Scriber

Brian Brown Responds
September 17, 2010
Daniel,
Sorry I took so long to respond. Gynandromorphs are indeed rare, but
insect populations are so large that they are almost inevitable. In some
insect they are even common. I imagine they don’t do very well in the
environment however, as their lack of symmetry in size would make them
clumsy. If you Google “gynandromorph frequency” you’ll see that there
are many studies on this subject.
Brian V. Brown
Curator, Entomology Section
Natural History Museum of Los Angeles County

Letter 2 – Tiger Swallowtail Caterpillar

 

Some kind of swallowtail?
Dear Bugman,
This caterpillar looks a lot like the tiger swallowtail one, shown on your site on 7-07-2004, except that it’s brown instead of green. Can these guys change colors depending on their background? This one was found today on a dark blue shirt after he/she rode into the house out in the country in northern Indiana. He/She is only about 2″ long and in addition to the great false eyes, he/she had lots of beautiful purple (yes, purple!) dots.
Diane M. Whisnant

Hi Diane,
Many caterpillars, including the Tiger Swallowtail you have sent in, the Spicebush Swallowtail, and some of the Sphinx Moths, change color before metamorphosis.

Letter 3 – Tiger Swallowtail Caterpillar

 

Orange Caterpillar
Orange caterpiller with plue dots observed outdoors in September in El Paso Texas.
Em
El Paso Texas

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Hi Em,
This is a Tiger Swallowtail Caterpillar.

Ed. Note: Another reader sent in a similar photo, and though it was not posted live, we did respond.  We got the following thank you note:
Thank You. I finally was able to Identify him about the time you sent me the answer. I only spent three or so hours searching and fixating on the darn thing, to find out that he(?) is getting ready to pupate. My family had to pry me from the computer so I would eat. LOL. I would have loved to have had the Web when I was a little girl. Good thing I had encyclopedias and a library.
sincerely grateful,
Patricia Neville

Letter 4 – Tiger Swallowtail Dark Form and Black Swallowtail

 

Two-tailed Tiger Swallowtail dark form??
Hi Bugman,
I L-O-V-E your website!!!! A co-worker turned me on to your site. Since then I have been able to identify many strange visitors (e.g. carpenter bees, giant resin bees, sow bug killers, etc.) to my Geneva, Illinois garden. I have also come to realize that most of my dark colored swallowtail visitors are not Black Swallowtail butterflies, as I had assumed, but rather dark form femail Tiger Swallowtails. But, I think that I have a new one for you. Is there a dark form of a Two-tailed Tiger Swallowtail? I have compared this butterfly to all of the other butterflies that I have photographed. I also searched your site & the internet. This appears to be the dark form of a Tiger Swallowtail, but it definitely has 2 tails. Is this possible? I thought that you might also enjoy this great picture of one of the few Black Swallowtail butterflies that have stopped by for a brief visit. Thanks ever so much! Keep up the good work!
Doris Bolin

Tiger Swallowtail: Dark Female Black Swallowtail

Happy Thanksgiving Doris,
The butterfly in question is a dark form of the female Tiger Swallowtail. There is an image on BugGuide that also has two tails. Thanks for sending our readership such a nice comparison of the dark female Tiger Swallowtail and a female Black Swallowtail.

Letter 5 – Black Tiger Swallowtail

 

Eastern Tiger Swallowtail Black Form
Location: Mound Minnesota
August 13, 2011 9:36 am
Hello from Minnesota. I have two photos to share with you of a Eastern Tiger Swallowtail, black form that I hope you’ll enjoy. This is a first for me and I was so excited to see it that I chased it through very thick & prickly thistle to get some photos. These photos were taken on 8.12.2011 in the late afternoon.
I also don’t know what that little orange bug is that’s sharing the thistle with the butterfly.
Signature: Laura

Black Tiger Swallowtail

Hi Laura,
Your photos are stunning.  They were worth the pinchy thistles.  A significant percentage of female Tiger Swallowtails are black, and this color variation is not found among the males.  Some are so dark it is difficult to make out the stripes.  Some females show transitional markings that are a combination of dark and light, and we were very fortunate to receive this photo last year of a half black, half striped Tiger Swallowtail that was also a gynandromorph, an insect hermaphrodite.  The left side of the individual is a dark female and the right side is a normal male.  The orange beetle is a Goldenrod Soldier Beetle or Pennsylvania Leatherwing.

Black Tiger Swallowtail

Hello, Daniel,
Thanks for the reply. And thanks for the information/links.  That one photo, the half & half/gynandromorph is amazing. Wow, what a find.
Anyway, thanks again.  I was pretty excited about my find and I’m hoping to see her again!
Laura

 

Letter 6 – Eastern Tiger Swallowtails: Dark Female, Light Females and Male

 

Subject: Easter tiger swallowtail, light and dark
Location: Troy, VA
September 16, 2016 11:55 am
I thought you might like these photos I took of female Eastern tiger swallowtails in their light and dark variations. A couple of weeks ago when the Joe Pye weed was blooming we had an extraordinary display of butterflies, particularly swallowtails. If people want to know how to attract butterflies, get some native weeds.
Signature: Grace Pedalino

Female Tiger Swallowtail: Dark Form
Female Tiger Swallowtail: Dark Form

Dear Grace,
We love your images of dark and light female Tiger Swallowtails, and we totally agree about Joe Pye Weed, Goldenrod, Milkweed and other native plants being perfect for attracting butterflies.  We hope you will be able to provide us with an image of a male Tiger Swallowtail in the near future.  We managed to get a few images several summers past of a very wary male Eastern Tiger Swallowtail, who can be recognized because of the absence of blue coloration on the lower wings.

Female Tiger Swallowtails
Female Tiger Swallowtails
Female Tiger Swallowtails
Female Tiger Swallowtails

Subject: Male tiger swallowtails
Location: Troy, VA
September 17, 2016 10:30 am
Hi Daniel,
I went through my photos and only had a couple of images with males. They were either not as plentiful as the females, or they were shyer. In two of the images you can see ailanthus webworm moths and in one the webworm moth and a skipper. I haven’t seen any swallowtails lately, so I don’t know if I will be able to get any other images. I hope you like these. What I have been seeing lately are skippers and crescent moths.
Signature: Grace Pedalino

Male Eastern Tiger Swallowtail
Male Eastern Tiger Swallowtail

Hi Grace,
Thanks so much for rounding out your Eastern Tiger Swallowtail posting with a few images of the male, who lacks the blue scales on his lower wings.

Male Eastern Tiger Swallowtail with Ailanthus Webworm Moth
Male Eastern Tiger Swallowtail with Ailanthus Webworm Moth

 

Letter 7 – Tiger Swallowtail: Black Morph

 

Butterfly
Hello.
I snapped this picture while out on a hike. I really thought it was a beautiful butterfly, and it looked like it was melting because of the appearance of droplets at the bottom of it’s wing. What I don’t know is what kind of butterfly it is. I apologize in advance if it has already been identified 100 times on your site.
Michael from Arkansas

Hi Michael from Arkansas,
This is a female Tiger Swallowtail. Some female Tiger Swallowtails do not exhibit the typical black and yellow striping, but the stripes are still evident in the wing pattern. Thanks for sending us your lovely photo.

Letter 8 – Tiger Swallowtail, but what species???

 

Canadian or Eastern Tiger Swallowtail?
March 15, 2010
This picture was taken May 2009 in upstate NY (near Albany). I’ve narrowed it down to either a Canadian or Eastern Tiger Swallowtail butterfly and wondered if you could help with a specific identification. Thank you!
Naomi
Albany, NY

Which Tiger Swallowtail???

Hi Naomi,
We haven’t the necessary skills to differentiate between the various Tiger Swallowtails without doing research.  Perhaps one of our readers can supply the answer in the event we cannot immediately turn our attention to the answer.  In the meanwhile, we are experiencing lilac envy.  We planted two lilacs in our garden last year that were bred to bloom in Southern California which does not have the necessary cold winter for the most lilacs.  We are still awaiting the spring growth, and at this time, we are uncertain if we will be getting any blooms.

Letter 9 – Tiger Swallowtail Caterpillar

 

Weird caterpillar in BC
Hi there:
I just found this guy today (Sep 5/05) crawling up the side of my house in the Okanagan Valley in British Columbia. Any ideas? He’s got several rows of 4 blue dots each and what look like false eyes on his back, and is about 1.5 inches long. I live next to an apple orchard and asked the owner who said he’d never seen anything like it. Let me know, please!
thx
Bill

Hi Bill,
This is a Tiger Swallowtail Caterpillar. Most specimens are green, but we have been getting images of these purplish brown ones this year. They feed on leaves from cherry, birch, poplar, ash and tulip trees. Perhaps they eat apple as well.

Ed. Note: Eric Eaton just provided this addendum: “From what I understand, the swallowtail caterpillars turn brown just before they pupate, which makes sense since they usually pupate on brown surfaces (tree branches, fence rails, and the like). That is a really nice specimen the person photographed. Keep up the great work. Eric ”

Letter 10 – Tiger Swallowtail Caterpillar

 

Brown Bug
Hi,
We found this bug outside of the Boys and Girls Club in Kelowna British Columbia. The kids want to know what it is – perhaps a Tersa Sphinx? Thanks a bunch!
Heather Painchaud

Hi Heather,
This is a Tiger Swallowtail Caterpillar.

Letter 11 – Tiger Swallowtail Caterpillar

 

a Mexican caterpillar
Hello from England.
This caterpillar was walking along the pavement outside Chapultepec park in Mexico City on 16th July 2006. Maybe it was looking for somewhere to pupate. It was about as big as my thumb (21⁄2 inches) and reminded me of the elephant hawkmoth caterpillar that we get in the UK. It had false eyes and raised the front of its body in an attempt to look fierce. Can you help?
Best Wishes
Phil Pemberton

Hi Phil,
This is a Tiger Swallowtail Caterpillar, and judging by the orange color, we agree it is getting ready to pupate. The caterpillars are green for most of their life, often turning orange or brown just before metamorphosis.

Letter 12 – Tiger Swallowtail Caterpillar

 

We’re stumped!!!
Hello from British Columbia !!! We were out in our backyard today and found this odd creature …… we figure it is in the caterpillar family but couldn’t find out it’s name ??? Could you help us out ??? Thanks
Stumped on Vancouver Island

Dear Stumped,
This is a Western Tiger Swallowtail Caterpillar, Papilio rutulus. They feed on the leaves of willows, aspens and other trees.

Letter 13 – Tiger Swallowtail Caterpillar

 

brown caterpillar with blue dots found in Chaparral, NM
Dear Bugman:
We found this caterpillar heading from a flowerbed to our vegetable garden in Chaparral, NM. Is it a Elephant Hawk-moth? Should we be concerned for our veggies?
Thank you for all your help,
Susan and Rick

Hi Susan and Rick,
This is a Tiger Swallowtail Caterpillar. It is getting ready to pupate, hence the brown coloration. It is normally green. It probably left the tree it was feeding upon and is searching for a pupation location.

Letter 14 – Tiger Swallowtail Caterpillar

 

Subject: What is this catapillar
Location: Vestal center ny
July 27, 2015 8:49 am
My kids saw this yesterday in vestal center, New York, which is near Binghamton n y. It was four inches long, brown in color violet dots like a collar yellow giant eyes with a violet dot in the middle,a forked yellow tongue and funky psychedelic colors down its back
Signature: Abby binder

Tiger Swallowtail Caterpillar with Osmeterium
Tiger Swallowtail Caterpillar with Osmeterium

Dear Abby,
This is a Tiger Swallowtail Caterpillar and it has extracted its osmeterium, a forked organ that produces a foul odor to deter predators.  What you have mistaken for “yellow giant eyes” are actually spots that resemble eyes, another defense mechanism to protect the docile caterpillar against predators.

Thank you so much….kids thrilled!

Letter 15 – Tiger Swallowtail Caterpillar

 

Subject: Caterpillar or what?
Location: South Cebtral Ontario, Canada
August 16, 2015 9:01 pm
This “bug” was discovered on the sidewalk in downtown Burlington, Ontario, Canada (off Lake Ontario). It had a head bobbing motion, and what looks like eyes on the sides of its head (fake illusion eyes?). It “sticks” to whatever it’s on very well and it’s mouth looked like a suction cup. Overall it looks cartoonish, almost right out of A Bugs Life. What is this?
Signature: Curious bugaphobe

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Dear Curious bugaphobe,
This is one of the Tiger Swallowtail Caterpillars, and there are many similar species that are regionally distinct, but that look quite similar physically.  Considering your location, we are guessing this is most likely a Canadian Tiger Swallowtail,
Papilio canadensis, which you can find pictured on BugGuide.

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Letter 16 – Tiger Swallowtail Caterpillar

 

Subject: Caterpillar
Location: southern ontario
August 25, 2015 6:41 pm
thought this might be a eastern swallowtail tiger but it’s black. Any help much appreciated.
Signature: Susan

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Dear Susan,
We cannot begin to speculate if this is an Eastern Tiger Swallowtail Caterpillar or a Canadian Tiger Swallowtail Caterpillar, and we suspect DNA analysis might be needed to determine its exact taxonomy.  Tiger Swallowtail Caterpillars often change from green to orange or purple as they are getting ready to transform into a chrysalis, and they also leave the trees whose leaves they were feeding upon in search of an ideal location for pupation.  In light of the variation in color of Tiger Swallowtails, from light to dark and in between, and even more strangely because of the presence of gynandromorphs, the correct term for an hermaphrodite, we can’t help but to wonder if the especially dark coloration of your individual might lead to a variation in the adult Tiger Swallowtail.

A duplicate sighting
Subject: Caterpillar
Location: MacTier, Ontario, Canada
August 25, 2015 10:19 am
Found this caterpillar on the greens at Rocky Crest Golf Course in MacTier, Ontario (CANADA). Would like to know what it is. Thanks.
Signature: Tricia McLelland

Dear Tricia,
This exact image was submitted by Susan and we responded.

Funny, as it was me who discovered it and took the photo. I have no idea who Susan is. Thanks.

Letter 17 – Tiger Swallowtail Caterpillar

 

Subject: Identify
Location: Texas
April 8, 2017 6:15 pm
This bug/insect was found in Texas.
Please identify.
Thanks
Signature: Mary Ann

Tiger Swallowtail Caterpillar

Dear Mary Ann,
This is one of the Tiger Swallowtail Caterpillars.  There are several species found in Texas and we haven’t the necessary skills to provide an exact species name.

Letter 18 – Tiger Swallowtail Caterpillar

 

Subject: Caterpie
Location: Central Texas
April 15, 2017 9:08 am
This little guy was outside of my house. I was curious to what he is. When I poked him he let out a forked “horn”. What is he?
Signature: Jorge

Tiger Swallowtail Caterpillar

Dear Jorge,
This is the caterpillar of a species from a group of butterflies in the genus
Papilio known collectively as Tiger Swallowtails.  The ranges of several species overlap in Texas and their caterpillars look quite similar.  We do not have the necessary skills to provide you with the exact species of your Tiger Swallowtail Caterpillar.  We can tell you that the “forked ‘horn'” you observed is a scent organ called the osmeterium that gives off a foul odor in order to deter predators.

Letter 19 – Tiger Swallowtail Caterpillar

 

Subject: MY BUG
Location: Taylors Falls Mn
August 7, 2017 12:46 am
This little guy fell out of a tree and landed next to my daughter. He sure made her jump. We took some pics , moved him to a safe place, and went on with our afternoon. Everyone is still wondering what he was.
Signature: Lane T.

Tiger Swallowtail Caterpillar

Dear Lane,
This is a Tiger Swallowtail Caterpillar and it will eventually become a large, beautiful, yellow and black striped adult Tiger Swallowtail.  We are tagging this posting with the Bug Humanitarian Award.

Letter 20 – Tiger Swallowtail Caterpillar

 

Subject:  What type of caterpillar is this?
Geographic location of the bug:  Eastern South Dakota
Date: 07/17/2018
Time: 09:50 AM EDT
Your letter to the bugman:  This guy reminds me of the hawk moths that frequent our petunias! But he’s not exactly like the ones on your page.  What is he!  He’s about 1.5 inches long.
How you want your letter signed:  Robin jarrett

Tiger Swallowtail Caterpillar

Dear Robin,
There are several different species of Tiger Swallowtails and they all have similar looking caterpillars.  South Dakota is included in the BugGuide data for sightings of the Eastern Tiger Swallowtail.  Its coloration indicates this Eastern Tiger Swallowtail Caterpillar is prepupal.

Letter 21 – Tiger Swallowtail Caterpillar

 

Subject:  What is this
Geographic location of the bug:  Richmond Va
Date: 06/12/2019
Time: 10:30 PM EDT
Your letter to the bugman:  What is this thing that was crawling on the sidewalk of my kids’ school today?
How you want your letter signed:  Crystal

Tiger Swallowtail Caterpillar

Dear Crystal,
This is the caterpillar of a Tiger Swallowtail butterfly.  There are several species in your area, and our best guess is that this is the Eastern Tiger Swallowtail,
Papilio glaucus.  Here is a BugGuide image for comparison.  The adult Eastern Tiger Swallowtail is a gorgeous butterfly.

Letter 22 – Tiger Swallowtail Caterpillar

 

Subject:  Tiger Swallowtail caterpillar
Geographic location of the bug:  Montrose Colorado US
Date: 07/05/2022
Time: 12:31 PM EDT
Your letter to the bugman:  I found this today and had the darnest time identifying it – until I found your site.  It is the last caterpillar stage to pupating.  Beautiful caterpillar.  I moved it to a safer location from the sidewalk so it will survive.  Thought the group would enjoy the photo.
How you want your letter signed : Claudette

Prepupal Tiger Swallowtail Caterpillar

Dear Claudette,
Thanks to your inquiry, Daniel the webmaster got Daniel the Bugman to check the What’s That Bug? email account and post your Patreon request which is the first identification request he has posted since November.  This is indeed a caterpillar of one of the  Tiger Swallowtail species and the orange color indicates that it is prepupal, meaning reading to undergo metamorphosis.  Daniel must do some research to try to determine the most likely species.  According to a comment posted to BugGuide:  “Colorado has both Eastern and Western Tiger Swallowtails. If you were west of the Great Plains in or near the mountains, it would likely be a Western Tiger. East from the mountains in the towns and along the ‘rivers’ of the Great Plains, you can see Eastern Tigers just like the ones in Texas, Nebraska, or Virginia. However, the most common Colorado species in the lower lying areas along either side of the mountains (say Pueblo, Denver, Grand Junction, etc.) is the Two-tailed Swallowtail, which also looks similar. And in the mountains there are also Pale Tiger Swallowtails (usually almost white). So, Colorado has four species of Tigers, and you could see all four in or near to Colorado Springs.”  Identifying the different species by caterpillar alone is beyond our expertise. We are not sure exactly where Montrose Colorado falls in the above description, but that could help you pin down which of the four Tiger Swallowtail species that are reported in Colorado you encountered.

Letter 23 – Tiger Swallowtail Caterpillar: Bird's Eye View

 

Tiger Swallowtail Caterpillar
Hi guys, great site you have, I’ve really enjoyed it! I thought you might like this pic of a Tiger Swallowtail cat taken from the predator’s perspective!!!
Peace and Blessings to All!!!
Cliff
Montreat , NC

Hi Cliff,
Awesome image. It is clearly understood how these eyespots, which are not real eyes, work as a protective device. The innocuous caterpillar take on the appearance of a large predatory reptile, easily startling and repelling any hungry bird that stumbles upon the tasty morsel.

Letter 24 – Tiger Swallowtail Caterpillar ready to pupate

 

Subject: is this a orange swallowtail
Location: Grand Junction, CO
July 19, 2014 9:49 am
what is this? my cat brought this in the house today. I took it away from her and put it back outside
Signature: Tracie

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Hi Tracie,
You are correct that this is one of the Tiger Swallowtail Caterpillars, which look very similar, and the orange color indicates that it is getting ready to pupate.  Several species are reported from Colorado according to BugGuide, including the Eastern Tiger Swallowtail and the Pale Swallowtail.

Letter 25 – Tiger Swallowtail Caterpillar with Osmeterium

 

Subject: Space alien or slug?
Location: Western pennsylvania
July 4, 2015 2:37 pm
July 4th found crawling under grill cover.
Sewickley , PA suburb of Pittsburgh
Signature: Johnnie dex

Tiger Swallowtail Caterpillar with Osmeterium
Tiger Swallowtail Caterpillar with Osmeterium

Dear Johnnie dex,
This is a Tiger Swallowtail Caterpillar, and it will eventually become an adult Tiger Swallowtail, a large yellow and black striped butterfly.  Your individual has everted its osmeterium, the forked organ that emits a foul odor, acting as a defense mechanism when the caterpillar feels threatened.

Thank you Daniel,
I had also identified the caterpillar as that of a tiger swallowtail. Although sorta creepy
looking I’m glad I left the caterpillar alone to go its way as eventually a butterfly may result.
Thank you for your quick response.
John

Letter 26 – Tiger Swallowtail Chrysalis

 

Tiger Swallow Tail
Hello – My children and I are wondering, will this chrysalis transform in to a beautiful Tiger Swallow Tail? We found him crawling up on a wall and housed him in our bug house. We identified the caterpillar that night and the next day he turned into a chrysalis. We read that the last generation of the Tiger Swallow Tail will chrysalis over winter. In the picture we sent, we showed the bug house hanging outside on our deck, under the eves. He has been there all winter. So we are hoping to see a beautiful Tiger Swallow Tail this spring. What time should this happen, approximately? In nature, the caterpillar would have endured winter on a branch or the wall we found him crawling on, right? Your site is awesome! Thank you for taking the time to share all your information and the great pictures.
Thank you,
Karla, Jacob & Isaac
Flathead Lake, Somers, Montana

Hi Karla, Jacob and Isaac,
This is most certainly a Swallowtail Chrysalis. They are distinct in the upright position with the girdle of silk around the midsection. We are guessing perhaps you will see an adult butterfly in May, or perhaps June. It really depends on when spring arrives in Montana. The butterfly will need nectar from flowers to survive, so they will not emerge until there is a food source available. Just make sure the Chrysalis does not get too warm before there are flowers.

Letter 27 – Tiger Swallowtail: Half Dark Morph

 

Mystery swallowtail
April 19, 2010
This has been a banner spring (2010) in Virginia for tiger swallowtails, our state insect. Both yellow and dark morphs have been crawling all over my azaleas, lilacs, and crabapples. But late in the day on April 6, this critter flew to my Sargent crabapple and caught my attention… and luckily my camera was handy. I can’t find any photos of swallowtails that have such prominent “eye spots” on the upper wing. The swallow-tails are blurry in the photo, but they were prominent; are there butterflies with swallow-tails that aren’t Swallowtails?
Winston
Louisa County, Virginia, USA

Tiger Swallowtail

Hi Winston,
This is a Tiger Swallowtail, which you point out has females that can be either light or dark, but occasionally an individual arises that can’t seem to make up its mind if it is light or dark, and an intermediate morph is produced.  This is one of those rarities.  We received another example back in August 2008, and it had more light coloration than your example, but it is similar.  Thanks for sending this wonderful anomaly our way.

Letter 28 – Tiger Swallowtail in Western Pennsylvania

 

Subject:  Tiger Swallowtail on Joe Pye Weed
Location:  near Villa Marie, Pennsylvania
August 12, 2013
Our editorial staff was excited to be in Eastern Ohio near the Pennsylvania state line in August as the Joe Pye Weed, Ironweed and Milkweed, all native wet meadow plants that attract butterflies, would be blooming. 

Tiger Swallowtail on Joe Pye Weed
Tiger Swallowtail on Joe Pye Weed

This Tiger Swallowtail proved to be a difficult subject, flying away each time we approached with the camera.  Growing up in eastern Mahoning County, we fondly referred to the parts of Pennsylvania just past the border as “the country” and we still enjoy drives in the area to view the wildlife.

Tiger Swallowtail visiting Joe Pye Weed
Tiger Swallowtail visiting Joe Pye Weed

 

Letter 29 – Tiger Swallowtail: transitional morph

 

Papilio Glaucus turnus dark form morph
Location:  northern VA
July 21, 2010 9:22 am
Hi, I believe I have just found a rare Papilio Glaucus turnus (Eastern Tiger Swallowtail) female dark form morph. In 60 years, I have not seen one save for the two photos on your website, neither of which appear to be the same as mine. I just wanted to share the marvel. Do you have anything to add?
Thanks!
Amateur Lepidopterist

Tiger Swallowtail: intermediate between light and dark morphs

Dear Amateur Lepidopterist,
Sadly, we were running late for work this morning, and though we opened your letter and saw your lovely mounted specimen images of an individual in a transitional phase between the normal light morph and the dark morph.  The true dark morph of a female Tiger Swallowtail is not as plentiful as the typical light yellow and black striped beauty.  The dark morph has a low contrast between the dark ground and the slightly darker stripes.  In the past several years, we have received two other examples of intermediary phases, and as these transitional morphs may be nearer to each of the extremes, which explains like our older examples are different than yours.  One example from earlier this year is of a living specimen that favors the darker morph.  An earlier example from 2008 is almost halfway between the two variations in coloration, with the black concentrated at the edges of the wings.  Your individual favors the light normal morph with just the centers of the wings being darker.  Thanks again for sending your photos.  We think it is interesting that these color variations, which only occur in female Tiger Swallowtails, exhibit such a wide range of possibilities.  This might make for an revealing genetics study.

P.S.  We do not condone insect collecting for anything but scientific purposes.  You should look up the proper format for labeling mounted specimens, and you should keep very specific records on the time and location and even weather conditions of the capture.

Ed. Note: When we sent a brief offline response to Amateur Lepidopterist this morning, here is what we wrote:  “Only that I am running out of the house to go to work and I wish I had the fifteen minutes it will take to post this right now.  I will post your letter this evening or tomorrow morning.  It is lovely and beautifully mounted.  Daniel

Letter 30 – Tiger Swallowtail: Transitional Morph

 

Unusual coloring on Eastern Tiger Swallowtail
Location:  floyd county, VA
August 7, 2010 3:32 pm
i was recently browsing your site, and was fascinated by Your feature the Tiger Swallowtail Gynandromorph.
Today while taking pictures of the butterflies on my butterfly bush i noticed one of the Eastern Tiger Swallow tails, had unusual coloring. It is the typical yellow, with stripes, but also has patches of dark. i’m curious as to whether it was a normal variation in pattern, or possible a form of mosaic Gynandromorph. Would love any info. i’ve been watching swallowtails for many years, and have never seen one quite like this.
tree

Tiger Swallowtail: Transitional Morph

Hi Tree,
Thanks for sending us your photo of a transitional morph of a female Tiger Swallowtail.  Most female Tiger Swallowtails are yellow with black stripes, but a small percentage are dark morphs, with the yellow ground color appearing very dark.  It is sometimes difficult to make out the stripes unless the light shines through the wings.  Even rarer are transitional morphs like yours, where the female is not truly light or dark, but an intermediary phase between the two typical morphs.  These transitional morphs exhibit varying degrees of coloration and markings.  We have several examples posted to our site from previous years, including a mounted specimen from July 2010.  The gynandromorph is a real rarity, not just among swallowtails, but among all butterflies or insects for that matter.  The bilateral sexual division, where the left half of the insect is one sex and the right half the other sex is especially unusual, though in many insects that do not exhibit extreme sexual dimorphism, many examples may go unnoticed.  The gynandromorph we just posted is an extreme example because the coloration difference between the left and right halves is so extreme.  We suspect gynandromorphs are infertile.

Tiger Swallowtail: Transitional Morph

Thank you so much for your reply and information.  It’s always exciting to see a new or unusual butterfly and be able to identify it! Thank you again!
~tree

Letter 31 – Tiger Swallowtail with Osmeterium

 

Subject: What is this creature
Location: Atlanta,Georgia
June 5, 2015 10:36 am
I saw this in my driveway one afternoon inching crawling and I have no idea what it is it looks like a worm and has what seems like a tongue and eyes, we live in the south Atlanta,ga this occured early June.
Signature: Please help me I’d love to know

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

This is the caterpillar of a Tiger Swallowtail, and what you have mistaken for a tongue is a retractable organ called an osmeterium that gives off a foul odor.  The odor coupled with the false eyes may give predatory birds the illusion that the tasty caterpillar is actually a much larger snake that could be dangerous to a bird.  Your submission will post live to our site later in June while we are away on holiday.

Letter 32 – Tiger Swallowtails and Monarch

 

Subject: Lots of Butterflies!!!
Location: Powell, Ohio
August 4, 2015 11:13 am
Two yellow swallowtails (I think), and a monarch, visited our garden today!!!! One swallowtail was noticeably bigger than the other and a bit raggedy. The monarch wasn’t cooperating for pictures, kept flirting about, but I got one off when it rested in a tree. The monarch was very interested in the milkweed plant we let grow by the patio! So pretty!
Signature: Amber

Female Tiger Swallowtail
Female Tiger Swallowtail

Dear Amber,
Thanks for sending us documentation of your day of butterfly watching.  The tattered Tiger Swallowtail is a female who can be distinguished from the male by the dusting of blue scales on the hind wings.

Tiger Swallowtail
Tiger Swallowtail
Monarch
Monarch

Letter 33 – Tiger Swallowtails Puddling

 

swallowtails mud puddeling
Hi there,
Love your site, here are some shots I took earlier in the summer from Lindsay, Ontario. Regard’s
Leslie

Hi Leslie,
Your photo of the Tiger Swallowtail Butterflies drinking moisture from muddy earth is quite beautiful, and a welcome addition to our site.

Reader Emails

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 Hermaphrodite

 

Tiger Swallowtail Gynandromorph
Location:  Hillsborough, NC
August 6, 2010 10:48 am
Hi guys,
I work at the Butterfly House at the NC Museum of Life & Science, Durham, NC. Your site is invaluable to us! A friend of ours, who lives locally, sent us this photo of a Tiger Swallowtail gynandromorph, taken last week. I’ve been hoping to see one for decades! If you look closely you can see small patches of wing from male tissue on the female (left) side. What we’d like to know is, does anyone have an idea of the frequency of such an occurrence, especially a near-perfect bilateral one like this?
Richard Stickney

Tiger Swallowtail Gyandromorph

Hi Richard,
Your letter and photograph have us very excited.  On a recent behind the scenes tour our staff was given at the Natural History Museum of Los Angeles, the entomologist, Dr. Brian Brown was very proud of two specimens of butterfly gynandromorphs he showed us, but neither was as spectacular as this Tiger Swallowtail.  Its coloration is even more dramatic since the female left half is also the less common dark morph.  We will contact Dr. Brown to see if he can provide any information on the frequency of occurrence of gynandromorphs in general, and in particular, such dramatic examples.  We are going to have to bump something from our feature section to include this marvelous documentation.  Mom who is visiting from Ohio identified the food plant as Joe Pye Weed, a common roadside wild flower.

Tiger Swallowtails, including rare Gynandromorph, and Ailanthus Webworm Moths nectaring on Joe Pye Weed

Update:  Julian Donahue suggests some resources
August 9, 2010
That is indeed a dramatic bilateral gynandromorph.
I don’t know of a single paper that answers your question about the frequency of this, but you might want to ask someone who works in butterfly genetics.
Try sending the photo and question to some of the following, all of whom work in this field (all are Ph.D.s):
Andy Brower
Thomas C. Emmel [head of the McGuire Center in Gainesville, which probably has a large collection of gynandromorphs)]
Paul Opler
Austin “Bob” Platt
Mark Scriber [“expert” on P. glaucus]
Good luck,
Julian P. Donahue

Ed. Note: What follows is the email we sent to the experts.
Dear Venerable Experts,
I was given your names and contact information by my friend and neighbor Julian Donahue.  My name is Daniel and I am a rank amateur who has been running the pop culture website What’s That Bug? on the internet for ten years.  This amazing photograph of a bilateral gynandromorph Tiger Swallowtail was recently sent to the website from North Carolina.  Can anyone provide any information on the degree of frequency of butterfly gynandromorphs and any information on their fecundity?  Thanks for your assistance.
Daniel Marlos

Paul Opler responds
Dear Daniel,
This is not only a bilateral gynandromorph, but is also showing some mosaic traits.
Beautiful image!
Paul Opler

Professor Andrew Brower responds
Hi Daniel,
You asked about fecundity of these:  I think zero – the genitalia are half male, half female, and I think they cannot engage in copulation.
I don’t know offhand the frequency with which bilateral gynandromorphs occur, but I know by their desirability that they must be rare – perhaps one in 10,000 (a random guess).
Andy Brower
Professor Andrew Brower
Department of Biology
Middle Tennessee State University
Murfreesboro, TN  37132   USA

Mark Scriber responds
Hi everyone;
This is a beautifual specimen. It is obviously nearly a bilateral gynandromorph, but with yellow mosaic color (probably male-like). We sometimes see yellow/dark mosaics (usually in the dark morph female wing background) in offspring our reared tiger swallowtials. I would estimate that these have occurred roughly at rates of 1  in 4,000-5000 offspring. The bilateral gynandromorph tigers are rarer, and might be found roughly once in 20, 000.  We have reviewed the role of hybridization in this phenomenon and some of the historical records in a recent paper:
Scriber, J. M.,  R.J. Mercader, H. Romack and M. Deering. 2009 Not all bilateral gynandromorphs are interspecific
hybrids: new Papilio specimens from field populations. J. Lepid. Soc. (color illustrated) 63 (1): 37-47
Best regards,
Mark Scriber

Brian Brown Responds
September 17, 2010
Daniel,
Sorry I took so long to respond. Gynandromorphs are indeed rare, but
insect populations are so large that they are almost inevitable. In some
insect they are even common. I imagine they don’t do very well in the
environment however, as their lack of symmetry in size would make them
clumsy. If you Google “gynandromorph frequency” you’ll see that there
are many studies on this subject.
Brian V. Brown
Curator, Entomology Section
Natural History Museum of Los Angeles County

Letter 2 – Tiger Swallowtail Caterpillar

 

Some kind of swallowtail?
Dear Bugman,
This caterpillar looks a lot like the tiger swallowtail one, shown on your site on 7-07-2004, except that it’s brown instead of green. Can these guys change colors depending on their background? This one was found today on a dark blue shirt after he/she rode into the house out in the country in northern Indiana. He/She is only about 2″ long and in addition to the great false eyes, he/she had lots of beautiful purple (yes, purple!) dots.
Diane M. Whisnant

Hi Diane,
Many caterpillars, including the Tiger Swallowtail you have sent in, the Spicebush Swallowtail, and some of the Sphinx Moths, change color before metamorphosis.

Letter 3 – Tiger Swallowtail Caterpillar

 

Orange Caterpillar
Orange caterpiller with plue dots observed outdoors in September in El Paso Texas.
Em
El Paso Texas

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Hi Em,
This is a Tiger Swallowtail Caterpillar.

Ed. Note: Another reader sent in a similar photo, and though it was not posted live, we did respond.  We got the following thank you note:
Thank You. I finally was able to Identify him about the time you sent me the answer. I only spent three or so hours searching and fixating on the darn thing, to find out that he(?) is getting ready to pupate. My family had to pry me from the computer so I would eat. LOL. I would have loved to have had the Web when I was a little girl. Good thing I had encyclopedias and a library.
sincerely grateful,
Patricia Neville

Letter 4 – Tiger Swallowtail Dark Form and Black Swallowtail

 

Two-tailed Tiger Swallowtail dark form??
Hi Bugman,
I L-O-V-E your website!!!! A co-worker turned me on to your site. Since then I have been able to identify many strange visitors (e.g. carpenter bees, giant resin bees, sow bug killers, etc.) to my Geneva, Illinois garden. I have also come to realize that most of my dark colored swallowtail visitors are not Black Swallowtail butterflies, as I had assumed, but rather dark form femail Tiger Swallowtails. But, I think that I have a new one for you. Is there a dark form of a Two-tailed Tiger Swallowtail? I have compared this butterfly to all of the other butterflies that I have photographed. I also searched your site & the internet. This appears to be the dark form of a Tiger Swallowtail, but it definitely has 2 tails. Is this possible? I thought that you might also enjoy this great picture of one of the few Black Swallowtail butterflies that have stopped by for a brief visit. Thanks ever so much! Keep up the good work!
Doris Bolin

Tiger Swallowtail: Dark Female Black Swallowtail

Happy Thanksgiving Doris,
The butterfly in question is a dark form of the female Tiger Swallowtail. There is an image on BugGuide that also has two tails. Thanks for sending our readership such a nice comparison of the dark female Tiger Swallowtail and a female Black Swallowtail.

Letter 5 – Black Tiger Swallowtail

 

Eastern Tiger Swallowtail Black Form
Location: Mound Minnesota
August 13, 2011 9:36 am
Hello from Minnesota. I have two photos to share with you of a Eastern Tiger Swallowtail, black form that I hope you’ll enjoy. This is a first for me and I was so excited to see it that I chased it through very thick & prickly thistle to get some photos. These photos were taken on 8.12.2011 in the late afternoon.
I also don’t know what that little orange bug is that’s sharing the thistle with the butterfly.
Signature: Laura

Black Tiger Swallowtail

Hi Laura,
Your photos are stunning.  They were worth the pinchy thistles.  A significant percentage of female Tiger Swallowtails are black, and this color variation is not found among the males.  Some are so dark it is difficult to make out the stripes.  Some females show transitional markings that are a combination of dark and light, and we were very fortunate to receive this photo last year of a half black, half striped Tiger Swallowtail that was also a gynandromorph, an insect hermaphrodite.  The left side of the individual is a dark female and the right side is a normal male.  The orange beetle is a Goldenrod Soldier Beetle or Pennsylvania Leatherwing.

Black Tiger Swallowtail

Hello, Daniel,
Thanks for the reply. And thanks for the information/links.  That one photo, the half & half/gynandromorph is amazing. Wow, what a find.
Anyway, thanks again.  I was pretty excited about my find and I’m hoping to see her again!
Laura

 

Letter 6 – Eastern Tiger Swallowtails: Dark Female, Light Females and Male

 

Subject: Easter tiger swallowtail, light and dark
Location: Troy, VA
September 16, 2016 11:55 am
I thought you might like these photos I took of female Eastern tiger swallowtails in their light and dark variations. A couple of weeks ago when the Joe Pye weed was blooming we had an extraordinary display of butterflies, particularly swallowtails. If people want to know how to attract butterflies, get some native weeds.
Signature: Grace Pedalino

Female Tiger Swallowtail: Dark Form
Female Tiger Swallowtail: Dark Form

Dear Grace,
We love your images of dark and light female Tiger Swallowtails, and we totally agree about Joe Pye Weed, Goldenrod, Milkweed and other native plants being perfect for attracting butterflies.  We hope you will be able to provide us with an image of a male Tiger Swallowtail in the near future.  We managed to get a few images several summers past of a very wary male Eastern Tiger Swallowtail, who can be recognized because of the absence of blue coloration on the lower wings.

Female Tiger Swallowtails
Female Tiger Swallowtails
Female Tiger Swallowtails
Female Tiger Swallowtails

Subject: Male tiger swallowtails
Location: Troy, VA
September 17, 2016 10:30 am
Hi Daniel,
I went through my photos and only had a couple of images with males. They were either not as plentiful as the females, or they were shyer. In two of the images you can see ailanthus webworm moths and in one the webworm moth and a skipper. I haven’t seen any swallowtails lately, so I don’t know if I will be able to get any other images. I hope you like these. What I have been seeing lately are skippers and crescent moths.
Signature: Grace Pedalino

Male Eastern Tiger Swallowtail
Male Eastern Tiger Swallowtail

Hi Grace,
Thanks so much for rounding out your Eastern Tiger Swallowtail posting with a few images of the male, who lacks the blue scales on his lower wings.

Male Eastern Tiger Swallowtail with Ailanthus Webworm Moth
Male Eastern Tiger Swallowtail with Ailanthus Webworm Moth

 

Letter 7 – Tiger Swallowtail: Black Morph

 

Butterfly
Hello.
I snapped this picture while out on a hike. I really thought it was a beautiful butterfly, and it looked like it was melting because of the appearance of droplets at the bottom of it’s wing. What I don’t know is what kind of butterfly it is. I apologize in advance if it has already been identified 100 times on your site.
Michael from Arkansas

Hi Michael from Arkansas,
This is a female Tiger Swallowtail. Some female Tiger Swallowtails do not exhibit the typical black and yellow striping, but the stripes are still evident in the wing pattern. Thanks for sending us your lovely photo.

Letter 8 – Tiger Swallowtail, but what species???

 

Canadian or Eastern Tiger Swallowtail?
March 15, 2010
This picture was taken May 2009 in upstate NY (near Albany). I’ve narrowed it down to either a Canadian or Eastern Tiger Swallowtail butterfly and wondered if you could help with a specific identification. Thank you!
Naomi
Albany, NY

Which Tiger Swallowtail???

Hi Naomi,
We haven’t the necessary skills to differentiate between the various Tiger Swallowtails without doing research.  Perhaps one of our readers can supply the answer in the event we cannot immediately turn our attention to the answer.  In the meanwhile, we are experiencing lilac envy.  We planted two lilacs in our garden last year that were bred to bloom in Southern California which does not have the necessary cold winter for the most lilacs.  We are still awaiting the spring growth, and at this time, we are uncertain if we will be getting any blooms.

Letter 9 – Tiger Swallowtail Caterpillar

 

Weird caterpillar in BC
Hi there:
I just found this guy today (Sep 5/05) crawling up the side of my house in the Okanagan Valley in British Columbia. Any ideas? He’s got several rows of 4 blue dots each and what look like false eyes on his back, and is about 1.5 inches long. I live next to an apple orchard and asked the owner who said he’d never seen anything like it. Let me know, please!
thx
Bill

Hi Bill,
This is a Tiger Swallowtail Caterpillar. Most specimens are green, but we have been getting images of these purplish brown ones this year. They feed on leaves from cherry, birch, poplar, ash and tulip trees. Perhaps they eat apple as well.

Ed. Note: Eric Eaton just provided this addendum: “From what I understand, the swallowtail caterpillars turn brown just before they pupate, which makes sense since they usually pupate on brown surfaces (tree branches, fence rails, and the like). That is a really nice specimen the person photographed. Keep up the great work. Eric ”

Letter 10 – Tiger Swallowtail Caterpillar

 

Brown Bug
Hi,
We found this bug outside of the Boys and Girls Club in Kelowna British Columbia. The kids want to know what it is – perhaps a Tersa Sphinx? Thanks a bunch!
Heather Painchaud

Hi Heather,
This is a Tiger Swallowtail Caterpillar.

Letter 11 – Tiger Swallowtail Caterpillar

 

a Mexican caterpillar
Hello from England.
This caterpillar was walking along the pavement outside Chapultepec park in Mexico City on 16th July 2006. Maybe it was looking for somewhere to pupate. It was about as big as my thumb (21⁄2 inches) and reminded me of the elephant hawkmoth caterpillar that we get in the UK. It had false eyes and raised the front of its body in an attempt to look fierce. Can you help?
Best Wishes
Phil Pemberton

Hi Phil,
This is a Tiger Swallowtail Caterpillar, and judging by the orange color, we agree it is getting ready to pupate. The caterpillars are green for most of their life, often turning orange or brown just before metamorphosis.

Letter 12 – Tiger Swallowtail Caterpillar

 

We’re stumped!!!
Hello from British Columbia !!! We were out in our backyard today and found this odd creature …… we figure it is in the caterpillar family but couldn’t find out it’s name ??? Could you help us out ??? Thanks
Stumped on Vancouver Island

Dear Stumped,
This is a Western Tiger Swallowtail Caterpillar, Papilio rutulus. They feed on the leaves of willows, aspens and other trees.

Letter 13 – Tiger Swallowtail Caterpillar

 

brown caterpillar with blue dots found in Chaparral, NM
Dear Bugman:
We found this caterpillar heading from a flowerbed to our vegetable garden in Chaparral, NM. Is it a Elephant Hawk-moth? Should we be concerned for our veggies?
Thank you for all your help,
Susan and Rick

Hi Susan and Rick,
This is a Tiger Swallowtail Caterpillar. It is getting ready to pupate, hence the brown coloration. It is normally green. It probably left the tree it was feeding upon and is searching for a pupation location.

Letter 14 – Tiger Swallowtail Caterpillar

 

Subject: What is this catapillar
Location: Vestal center ny
July 27, 2015 8:49 am
My kids saw this yesterday in vestal center, New York, which is near Binghamton n y. It was four inches long, brown in color violet dots like a collar yellow giant eyes with a violet dot in the middle,a forked yellow tongue and funky psychedelic colors down its back
Signature: Abby binder

Tiger Swallowtail Caterpillar with Osmeterium
Tiger Swallowtail Caterpillar with Osmeterium

Dear Abby,
This is a Tiger Swallowtail Caterpillar and it has extracted its osmeterium, a forked organ that produces a foul odor to deter predators.  What you have mistaken for “yellow giant eyes” are actually spots that resemble eyes, another defense mechanism to protect the docile caterpillar against predators.

Thank you so much….kids thrilled!

Letter 15 – Tiger Swallowtail Caterpillar

 

Subject: Caterpillar or what?
Location: South Cebtral Ontario, Canada
August 16, 2015 9:01 pm
This “bug” was discovered on the sidewalk in downtown Burlington, Ontario, Canada (off Lake Ontario). It had a head bobbing motion, and what looks like eyes on the sides of its head (fake illusion eyes?). It “sticks” to whatever it’s on very well and it’s mouth looked like a suction cup. Overall it looks cartoonish, almost right out of A Bugs Life. What is this?
Signature: Curious bugaphobe

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Dear Curious bugaphobe,
This is one of the Tiger Swallowtail Caterpillars, and there are many similar species that are regionally distinct, but that look quite similar physically.  Considering your location, we are guessing this is most likely a Canadian Tiger Swallowtail,
Papilio canadensis, which you can find pictured on BugGuide.

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Letter 16 – Tiger Swallowtail Caterpillar

 

Subject: Caterpillar
Location: southern ontario
August 25, 2015 6:41 pm
thought this might be a eastern swallowtail tiger but it’s black. Any help much appreciated.
Signature: Susan

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Dear Susan,
We cannot begin to speculate if this is an Eastern Tiger Swallowtail Caterpillar or a Canadian Tiger Swallowtail Caterpillar, and we suspect DNA analysis might be needed to determine its exact taxonomy.  Tiger Swallowtail Caterpillars often change from green to orange or purple as they are getting ready to transform into a chrysalis, and they also leave the trees whose leaves they were feeding upon in search of an ideal location for pupation.  In light of the variation in color of Tiger Swallowtails, from light to dark and in between, and even more strangely because of the presence of gynandromorphs, the correct term for an hermaphrodite, we can’t help but to wonder if the especially dark coloration of your individual might lead to a variation in the adult Tiger Swallowtail.

A duplicate sighting
Subject: Caterpillar
Location: MacTier, Ontario, Canada
August 25, 2015 10:19 am
Found this caterpillar on the greens at Rocky Crest Golf Course in MacTier, Ontario (CANADA). Would like to know what it is. Thanks.
Signature: Tricia McLelland

Dear Tricia,
This exact image was submitted by Susan and we responded.

Funny, as it was me who discovered it and took the photo. I have no idea who Susan is. Thanks.

Letter 17 – Tiger Swallowtail Caterpillar

 

Subject: Identify
Location: Texas
April 8, 2017 6:15 pm
This bug/insect was found in Texas.
Please identify.
Thanks
Signature: Mary Ann

Tiger Swallowtail Caterpillar

Dear Mary Ann,
This is one of the Tiger Swallowtail Caterpillars.  There are several species found in Texas and we haven’t the necessary skills to provide an exact species name.

Letter 18 – Tiger Swallowtail Caterpillar

 

Subject: Caterpie
Location: Central Texas
April 15, 2017 9:08 am
This little guy was outside of my house. I was curious to what he is. When I poked him he let out a forked “horn”. What is he?
Signature: Jorge

Tiger Swallowtail Caterpillar

Dear Jorge,
This is the caterpillar of a species from a group of butterflies in the genus
Papilio known collectively as Tiger Swallowtails.  The ranges of several species overlap in Texas and their caterpillars look quite similar.  We do not have the necessary skills to provide you with the exact species of your Tiger Swallowtail Caterpillar.  We can tell you that the “forked ‘horn'” you observed is a scent organ called the osmeterium that gives off a foul odor in order to deter predators.

Letter 19 – Tiger Swallowtail Caterpillar

 

Subject: MY BUG
Location: Taylors Falls Mn
August 7, 2017 12:46 am
This little guy fell out of a tree and landed next to my daughter. He sure made her jump. We took some pics , moved him to a safe place, and went on with our afternoon. Everyone is still wondering what he was.
Signature: Lane T.

Tiger Swallowtail Caterpillar

Dear Lane,
This is a Tiger Swallowtail Caterpillar and it will eventually become a large, beautiful, yellow and black striped adult Tiger Swallowtail.  We are tagging this posting with the Bug Humanitarian Award.

Letter 20 – Tiger Swallowtail Caterpillar

 

Subject:  What type of caterpillar is this?
Geographic location of the bug:  Eastern South Dakota
Date: 07/17/2018
Time: 09:50 AM EDT
Your letter to the bugman:  This guy reminds me of the hawk moths that frequent our petunias! But he’s not exactly like the ones on your page.  What is he!  He’s about 1.5 inches long.
How you want your letter signed:  Robin jarrett

Tiger Swallowtail Caterpillar

Dear Robin,
There are several different species of Tiger Swallowtails and they all have similar looking caterpillars.  South Dakota is included in the BugGuide data for sightings of the Eastern Tiger Swallowtail.  Its coloration indicates this Eastern Tiger Swallowtail Caterpillar is prepupal.

Letter 21 – Tiger Swallowtail Caterpillar

 

Subject:  What is this
Geographic location of the bug:  Richmond Va
Date: 06/12/2019
Time: 10:30 PM EDT
Your letter to the bugman:  What is this thing that was crawling on the sidewalk of my kids’ school today?
How you want your letter signed:  Crystal

Tiger Swallowtail Caterpillar

Dear Crystal,
This is the caterpillar of a Tiger Swallowtail butterfly.  There are several species in your area, and our best guess is that this is the Eastern Tiger Swallowtail,
Papilio glaucus.  Here is a BugGuide image for comparison.  The adult Eastern Tiger Swallowtail is a gorgeous butterfly.

Letter 22 – Tiger Swallowtail Caterpillar

 

Subject:  Tiger Swallowtail caterpillar
Geographic location of the bug:  Montrose Colorado US
Date: 07/05/2022
Time: 12:31 PM EDT
Your letter to the bugman:  I found this today and had the darnest time identifying it – until I found your site.  It is the last caterpillar stage to pupating.  Beautiful caterpillar.  I moved it to a safer location from the sidewalk so it will survive.  Thought the group would enjoy the photo.
How you want your letter signed : Claudette

Prepupal Tiger Swallowtail Caterpillar

Dear Claudette,
Thanks to your inquiry, Daniel the webmaster got Daniel the Bugman to check the What’s That Bug? email account and post your Patreon request which is the first identification request he has posted since November.  This is indeed a caterpillar of one of the  Tiger Swallowtail species and the orange color indicates that it is prepupal, meaning reading to undergo metamorphosis.  Daniel must do some research to try to determine the most likely species.  According to a comment posted to BugGuide:  “Colorado has both Eastern and Western Tiger Swallowtails. If you were west of the Great Plains in or near the mountains, it would likely be a Western Tiger. East from the mountains in the towns and along the ‘rivers’ of the Great Plains, you can see Eastern Tigers just like the ones in Texas, Nebraska, or Virginia. However, the most common Colorado species in the lower lying areas along either side of the mountains (say Pueblo, Denver, Grand Junction, etc.) is the Two-tailed Swallowtail, which also looks similar. And in the mountains there are also Pale Tiger Swallowtails (usually almost white). So, Colorado has four species of Tigers, and you could see all four in or near to Colorado Springs.”  Identifying the different species by caterpillar alone is beyond our expertise. We are not sure exactly where Montrose Colorado falls in the above description, but that could help you pin down which of the four Tiger Swallowtail species that are reported in Colorado you encountered.

Letter 23 – Tiger Swallowtail Caterpillar: Bird's Eye View

 

Tiger Swallowtail Caterpillar
Hi guys, great site you have, I’ve really enjoyed it! I thought you might like this pic of a Tiger Swallowtail cat taken from the predator’s perspective!!!
Peace and Blessings to All!!!
Cliff
Montreat , NC

Hi Cliff,
Awesome image. It is clearly understood how these eyespots, which are not real eyes, work as a protective device. The innocuous caterpillar take on the appearance of a large predatory reptile, easily startling and repelling any hungry bird that stumbles upon the tasty morsel.

Letter 24 – Tiger Swallowtail Caterpillar ready to pupate

 

Subject: is this a orange swallowtail
Location: Grand Junction, CO
July 19, 2014 9:49 am
what is this? my cat brought this in the house today. I took it away from her and put it back outside
Signature: Tracie

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

Hi Tracie,
You are correct that this is one of the Tiger Swallowtail Caterpillars, which look very similar, and the orange color indicates that it is getting ready to pupate.  Several species are reported from Colorado according to BugGuide, including the Eastern Tiger Swallowtail and the Pale Swallowtail.

Letter 25 – Tiger Swallowtail Caterpillar with Osmeterium

 

Subject: Space alien or slug?
Location: Western pennsylvania
July 4, 2015 2:37 pm
July 4th found crawling under grill cover.
Sewickley , PA suburb of Pittsburgh
Signature: Johnnie dex

Tiger Swallowtail Caterpillar with Osmeterium
Tiger Swallowtail Caterpillar with Osmeterium

Dear Johnnie dex,
This is a Tiger Swallowtail Caterpillar, and it will eventually become an adult Tiger Swallowtail, a large yellow and black striped butterfly.  Your individual has everted its osmeterium, the forked organ that emits a foul odor, acting as a defense mechanism when the caterpillar feels threatened.

Thank you Daniel,
I had also identified the caterpillar as that of a tiger swallowtail. Although sorta creepy
looking I’m glad I left the caterpillar alone to go its way as eventually a butterfly may result.
Thank you for your quick response.
John

Letter 26 – Tiger Swallowtail Chrysalis

 

Tiger Swallow Tail
Hello – My children and I are wondering, will this chrysalis transform in to a beautiful Tiger Swallow Tail? We found him crawling up on a wall and housed him in our bug house. We identified the caterpillar that night and the next day he turned into a chrysalis. We read that the last generation of the Tiger Swallow Tail will chrysalis over winter. In the picture we sent, we showed the bug house hanging outside on our deck, under the eves. He has been there all winter. So we are hoping to see a beautiful Tiger Swallow Tail this spring. What time should this happen, approximately? In nature, the caterpillar would have endured winter on a branch or the wall we found him crawling on, right? Your site is awesome! Thank you for taking the time to share all your information and the great pictures.
Thank you,
Karla, Jacob & Isaac
Flathead Lake, Somers, Montana

Hi Karla, Jacob and Isaac,
This is most certainly a Swallowtail Chrysalis. They are distinct in the upright position with the girdle of silk around the midsection. We are guessing perhaps you will see an adult butterfly in May, or perhaps June. It really depends on when spring arrives in Montana. The butterfly will need nectar from flowers to survive, so they will not emerge until there is a food source available. Just make sure the Chrysalis does not get too warm before there are flowers.

Letter 27 – Tiger Swallowtail: Half Dark Morph

 

Mystery swallowtail
April 19, 2010
This has been a banner spring (2010) in Virginia for tiger swallowtails, our state insect. Both yellow and dark morphs have been crawling all over my azaleas, lilacs, and crabapples. But late in the day on April 6, this critter flew to my Sargent crabapple and caught my attention… and luckily my camera was handy. I can’t find any photos of swallowtails that have such prominent “eye spots” on the upper wing. The swallow-tails are blurry in the photo, but they were prominent; are there butterflies with swallow-tails that aren’t Swallowtails?
Winston
Louisa County, Virginia, USA

Tiger Swallowtail

Hi Winston,
This is a Tiger Swallowtail, which you point out has females that can be either light or dark, but occasionally an individual arises that can’t seem to make up its mind if it is light or dark, and an intermediate morph is produced.  This is one of those rarities.  We received another example back in August 2008, and it had more light coloration than your example, but it is similar.  Thanks for sending this wonderful anomaly our way.

Letter 28 – Tiger Swallowtail in Western Pennsylvania

 

Subject:  Tiger Swallowtail on Joe Pye Weed
Location:  near Villa Marie, Pennsylvania
August 12, 2013
Our editorial staff was excited to be in Eastern Ohio near the Pennsylvania state line in August as the Joe Pye Weed, Ironweed and Milkweed, all native wet meadow plants that attract butterflies, would be blooming. 

Tiger Swallowtail on Joe Pye Weed
Tiger Swallowtail on Joe Pye Weed

This Tiger Swallowtail proved to be a difficult subject, flying away each time we approached with the camera.  Growing up in eastern Mahoning County, we fondly referred to the parts of Pennsylvania just past the border as “the country” and we still enjoy drives in the area to view the wildlife.

Tiger Swallowtail visiting Joe Pye Weed
Tiger Swallowtail visiting Joe Pye Weed

 

Letter 29 – Tiger Swallowtail: transitional morph

 

Papilio Glaucus turnus dark form morph
Location:  northern VA
July 21, 2010 9:22 am
Hi, I believe I have just found a rare Papilio Glaucus turnus (Eastern Tiger Swallowtail) female dark form morph. In 60 years, I have not seen one save for the two photos on your website, neither of which appear to be the same as mine. I just wanted to share the marvel. Do you have anything to add?
Thanks!
Amateur Lepidopterist

Tiger Swallowtail: intermediate between light and dark morphs

Dear Amateur Lepidopterist,
Sadly, we were running late for work this morning, and though we opened your letter and saw your lovely mounted specimen images of an individual in a transitional phase between the normal light morph and the dark morph.  The true dark morph of a female Tiger Swallowtail is not as plentiful as the typical light yellow and black striped beauty.  The dark morph has a low contrast between the dark ground and the slightly darker stripes.  In the past several years, we have received two other examples of intermediary phases, and as these transitional morphs may be nearer to each of the extremes, which explains like our older examples are different than yours.  One example from earlier this year is of a living specimen that favors the darker morph.  An earlier example from 2008 is almost halfway between the two variations in coloration, with the black concentrated at the edges of the wings.  Your individual favors the light normal morph with just the centers of the wings being darker.  Thanks again for sending your photos.  We think it is interesting that these color variations, which only occur in female Tiger Swallowtails, exhibit such a wide range of possibilities.  This might make for an revealing genetics study.

P.S.  We do not condone insect collecting for anything but scientific purposes.  You should look up the proper format for labeling mounted specimens, and you should keep very specific records on the time and location and even weather conditions of the capture.

Ed. Note: When we sent a brief offline response to Amateur Lepidopterist this morning, here is what we wrote:  “Only that I am running out of the house to go to work and I wish I had the fifteen minutes it will take to post this right now.  I will post your letter this evening or tomorrow morning.  It is lovely and beautifully mounted.  Daniel

Letter 30 – Tiger Swallowtail: Transitional Morph

 

Unusual coloring on Eastern Tiger Swallowtail
Location:  floyd county, VA
August 7, 2010 3:32 pm
i was recently browsing your site, and was fascinated by Your feature the Tiger Swallowtail Gynandromorph.
Today while taking pictures of the butterflies on my butterfly bush i noticed one of the Eastern Tiger Swallow tails, had unusual coloring. It is the typical yellow, with stripes, but also has patches of dark. i’m curious as to whether it was a normal variation in pattern, or possible a form of mosaic Gynandromorph. Would love any info. i’ve been watching swallowtails for many years, and have never seen one quite like this.
tree

Tiger Swallowtail: Transitional Morph

Hi Tree,
Thanks for sending us your photo of a transitional morph of a female Tiger Swallowtail.  Most female Tiger Swallowtails are yellow with black stripes, but a small percentage are dark morphs, with the yellow ground color appearing very dark.  It is sometimes difficult to make out the stripes unless the light shines through the wings.  Even rarer are transitional morphs like yours, where the female is not truly light or dark, but an intermediary phase between the two typical morphs.  These transitional morphs exhibit varying degrees of coloration and markings.  We have several examples posted to our site from previous years, including a mounted specimen from July 2010.  The gynandromorph is a real rarity, not just among swallowtails, but among all butterflies or insects for that matter.  The bilateral sexual division, where the left half of the insect is one sex and the right half the other sex is especially unusual, though in many insects that do not exhibit extreme sexual dimorphism, many examples may go unnoticed.  The gynandromorph we just posted is an extreme example because the coloration difference between the left and right halves is so extreme.  We suspect gynandromorphs are infertile.

Tiger Swallowtail: Transitional Morph

Thank you so much for your reply and information.  It’s always exciting to see a new or unusual butterfly and be able to identify it! Thank you again!
~tree

Letter 31 – Tiger Swallowtail with Osmeterium

 

Subject: What is this creature
Location: Atlanta,Georgia
June 5, 2015 10:36 am
I saw this in my driveway one afternoon inching crawling and I have no idea what it is it looks like a worm and has what seems like a tongue and eyes, we live in the south Atlanta,ga this occured early June.
Signature: Please help me I’d love to know

Tiger Swallowtail Caterpillar
Tiger Swallowtail Caterpillar

This is the caterpillar of a Tiger Swallowtail, and what you have mistaken for a tongue is a retractable organ called an osmeterium that gives off a foul odor.  The odor coupled with the false eyes may give predatory birds the illusion that the tasty caterpillar is actually a much larger snake that could be dangerous to a bird.  Your submission will post live to our site later in June while we are away on holiday.

Letter 32 – Tiger Swallowtails and Monarch

 

Subject: Lots of Butterflies!!!
Location: Powell, Ohio
August 4, 2015 11:13 am
Two yellow swallowtails (I think), and a monarch, visited our garden today!!!! One swallowtail was noticeably bigger than the other and a bit raggedy. The monarch wasn’t cooperating for pictures, kept flirting about, but I got one off when it rested in a tree. The monarch was very interested in the milkweed plant we let grow by the patio! So pretty!
Signature: Amber

Female Tiger Swallowtail
Female Tiger Swallowtail

Dear Amber,
Thanks for sending us documentation of your day of butterfly watching.  The tattered Tiger Swallowtail is a female who can be distinguished from the male by the dusting of blue scales on the hind wings.

Tiger Swallowtail
Tiger Swallowtail
Monarch
Monarch

Letter 33 – Tiger Swallowtails Puddling

 

swallowtails mud puddeling
Hi there,
Love your site, here are some shots I took earlier in the summer from Lindsay, Ontario. Regard’s
Leslie

Hi Leslie,
Your photo of the Tiger Swallowtail Butterflies drinking moisture from muddy earth is quite beautiful, and a welcome addition to our site.

Reader Emails

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.

Reader Emails

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.

Reader Emails

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.

Authors

    by
  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

31 thoughts on “Black Swallowtail vs Tiger Swallowtail: Decoding the Differences”

  1. BugGuide says “inner margin of hindwing upperside has wide black stripe (whereas the otherwise similar – though larger – Eastern Tiger Swallowtail has a thin black stripe in that area)”. A fairly subjective assessment, but from comparing images I think this looks more like the Canadian tiger swallowtail.

    Reply
  2. Me again, glad to find out my tiger swallowtail caterpillar has made it’s chrysalis. It was hanging off the top a little. That had me worried! But, as I’m seeing in this picture- it’s normal. My caterpillar looks like he’s in his chrysalis halfway though.. At the very bottom, it doesn’t look like his body his covered with the cacoon like the top of his body is.

    Reply
  3. Hi!

    I just wanted to thank you for posting this information! My students and I just found this caterpillar at recess in Mexico City, and we went on an info hunt to find out what it was! We live very close to Chapultepec Park, and your picture and behavior descriptions really helped us be sure we knew what we found!

    Best,
    Miss Ellie’s 4G Class!

    Reply
  4. We found one tiger swallowtail caterpillar in Alton, Utah today, Wednesday, 9/17/2014. At least we think it was one of those. The grandkids had a great time watching it. What does it eat?

    Reply
  5. Hello all,
    My daughters found one about a month ago on our patio! In Camp Verde Arizona! We promptly put it into a big glass vase and put dirt, sticks and a bunch of home grown dill with him and he is a cocoon now! Now we just have to wait until may or June next year for it to come out! 😉 we will let y’all know how it goes!

    Reply
    • As a point of clarification, a cocoon is a pupal covering, generally made of silk. The naked pupa of a Butterfly is called a chrysalis.

      Reply
  6. Hi Daniel,

    I’m glad you lke the photos. I’ll look and see if I have an photos of males. I also have some nice pictures of some kind of crescent butterfly, would you be interested in those as well?

    Thanks

    Reply
  7. We just found a tiger swallowtail caterpillar in Colorado and created a home for it. I am very limited in my caterpillar knowledge and do not want to starve the poor thing. My kids are so excited to watch the process of it turning into a butterfly. We found it in the sandbox at our park. Is there a preference of trees for them to feed on or food?

    Reply
  8. OMG we just found one in my front door, but we had no clue what it was. It smelled horrible so we took it with a stick and threw it away… My sister took pictures. I called an exterminator to fumigate around the house not knowing what it was… ?

    Reply
  9. I was looking at this because we saw a beautiful but strange butterfly at the garden center where I work this morning. There was a clear tiger swallowtail pattern, but the normally yellow sections were nearly as dark as the stripes. Neither I nor my coworkers knew what it was. I wish I’d stopped for a picture, but it was already over ninety degrees out and we all had watering left to do. If I see it again, I’ll snap a pic.

    Reply

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