Anise Swallowtail: All You Need to Know for Butterfly Enthusiasts

The Anise Swallowtail is an enchanting butterfly belonging to the Papilio genus. It is known for its captivating presence and unique life cycle adjustments that align with its host plants’ seasonality.

Native to North America, these butterflies are often found in various habitats, including bare hills, mountains, fields, and gardens. Anise Swallowtails display a stunning color pattern, featuring yellow and black markings on their wings.

Furthermore, they are known to have an ecotype arrangement, with different populations adapting to their host plants’ seasonal changes.

This fascinating adaptation has helped them thrive in various environments across their geographic range.

To fully appreciate the Anise Swallowtail, one should take note of its remarkable traits:

• Yellow and black wing color pattern
• Found in diverse habitats

It is crucial to protect and conserve these beautiful butterflies to ensure their continued existence for future generations.

Anise Swallowtail: Overview

The Anise Swallowtail (Papilio zelicaon) is a beautiful butterfly native to western North America. It’s well-known for its striking appearance and affinity for various host plants.

Scientific Classification

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

Physical Description

Anise Swallowtails are medium-sized butterflies with a wingspan of 52-80 mm (2.0 to 3.1 in). They exhibit a coloration pattern with yellow and black bands and blue, red, or orange spots near the bottom. Some distinctive features include:

• Yellow and black bands on wings
• Blue, red, or orange spots near the bottom of the wings
• A prominent “tail” on the hind wings

Distribution and Habitat

Anise Swallowtails are found throughout the western regions of North America – from Canada, throughout the United States, and down to Mexico, including the Baja California Peninsula.

As stated above, they are versatile in their habitat preferences and can be found in various environments such as:

• Woodland edges
• Rocky outcrops
• Desert canyons
• Suburban gardens

This adaptation to different habitats has led to a complex set of ecological races and interactions with various host plants.

Life Cycle and Behavior

Eggs

Anise Swallowtail eggs are:

• Round
• Yellow-green in color

Eggs are laid singly on host plants. They hatch in about 4-6 days, depending on temperature.

Larvae and Caterpillars

Anise Swallowtail larvae, or caterpillars, are:

• The first instar has a black body white stripes or white spots. At the fifth instar, they become green with black and yellow stripes.
• Black bands on their body
• Red eyespots

They develop through various stages, called instars. Anise Swallowtail caterpillars:

• Eat host plant leaves when young
• Consume inflorescences when older
• Build no nest
• Wander for up to 24 days before pupating

Pupa and Chrysalis

Pupa stage:

• Called chrysalis
• Dark black pupil
• Attached to a branch using silk

Anise Swallowtail pupa overwinters, meaning it undergoes metamorphosis during winter.

Adult Butterfly

Anise Swallowtail adult butterfly features:

• Wingspan of up to 3.1 inches
• Black with yellow, blue, orange, and red markings

Feature	Anise Swallowtail
Wingspan Range	2.0 to 3.1 in
Adult Coloration	Black, Yellow, Blue, Orange, Red

Identification and Differences

Western Tiger Swallowtail

The Western Tiger Swallowtail (Papilio rutulus) is a large butterfly, characterized by its vibrant yellow and black stripes. Key features include:

• Yellow and black striping patterns on the wings
• Blue spots along the lower edge of the hindwing
• Striking resemblance to the Anise Swallowtail

Comparing Anise Swallowtail and Western Tiger Swallowtail:

Features	Anise Swallowtail	Western Tiger Swallowtail
Yellow Stripes	Thin, narrow, evenly spaced	Wider, sometimes uneven
Vertical Black Striping Pattern	Absent	Present
Blue Spots	Along the edge of the hindwing, small	Across the lower hindwing, larger

Subspecies of Anise Swallowtail

Multiple subspecies of Anise Swallowtail (Papilio zelicaon) exist, each adapted to specific ecological regions based on their host plants.

Key characteristics of Anise Swallowtail and subspecies variation:

• The yellow band along the hindwing edge varies in width
• Blue spots, size, and intensity may differ among subspecies
• Black stripes on the forewing and hindwing

For example, the subspecies Papilio zelicaon Nitra has a solid black-to-blue swallowtail. Recognizing these differences among subspecies will enhance your butterfly identification skills.

In conclusion, identifying the Anise Swallowtail and its related subspecies involves observing the distinct stripe patterns, blue spots, and yellow bands on their wings.

Comparing them to the Western Tiger Swallowtail will aid in differentiating them more accurately.

Host Plants and Diet

Apiaceae Family

The Anise Swallowtail butterfly primarily feeds on plants from the Apiaceae family. This family, also known as the carrot family, consists of several species that act as host plants for the Anise Swallowtail caterpillar, which include:

• Fennel
• Parsley
• Carrot

These plants provide essential nutrients for the caterpillar’s growth and development.

Rutaceae Family

Another significant host family for the Anise Swallowtail is the Rutaceae family, also known as the citrus family. This family comprises various citrus trees, which serve as additional host plants for the caterpillar.

Examples of Rutaceae family host plants include:

• Orange trees
• Lemon trees
• Lime trees

These trees offer an alternative food source and habitat for the Anise Swallowtail caterpillar.

Comparison Table:

	Apiaceae Family	Rutaceae Family
Example 1	Fennel (Sweet Fennel)	Orange Trees
Example 2	Parsley	Lemon Trees
Example 3	Carrot	Lime Trees
Benefits	Wide range of plants	Offers alternative hosts

In conclusion, Anise Swallowtail butterflies rely on both Apiaceae and Rutaceae families as host plants for their caterpillars. Planting these species in a garden can help support the Swallowtail butterfly populations.

Conservation and Gardening

Creating a Butterfly-Friendly Garden

An Anise Swallowtail-friendly garden needs:

• Host plants: Anise swallowtails lay eggs on plants like Illicium parviflorum, a licorice-scented shrub native to the southeastern United States.
• Nectar sources: Adult swallowtails feed on flower nectar. Plant a variety of flowering plants, mixing colors and shapes, to attract them.
• Shelter: Butterflies need safe resting spots, such as tall grasses, vegetation near the ground, or garden sheds.

NatureServe Conservation Status

NatureServe ranks butterfly species based on their level of risk. The Anise Swallowtail Papilio zelicaon has not yet been ranked. However, it occurs in diverse habitats, such as open areas, roadsides, and bare hills.

This adaptability suggests a degree of resilience in the face of habitat changes.

Butterfly Species	NatureServe Status
Anise Swallowtail	Not Ranked
Black Swallowtail	G5 (Secure)
Florida Anise	G4 (Apparently Secure)

Interesting Facts and Trivia

The Anise Swallowtail is a fascinating butterfly species that belongs to the Papilionidae family. Here are some captivating facts about this butterfly:

• As a member of the swallowtail group, the Anise Swallowtail has tail-like extensions on its hind wings.
• Their striking appearance includes a combination of black, yellow, and blue colors on their wings.
• Anise Swallowtail larvae are known for their bird droppings-like appearance as a camouflage technique

Finally, here’s a comparison table that highlights the differences between Anise Swallowtail and Black Swallowtail, another popular species:

Characteristic	Anise Swallowtail	Black Swallowtail
Wing Colors	Black, Yellow, Blue	Black, Yellow, Blue, Orange
Habitat Preferences	Mountains, Coastal Areas	Open Areas, Meadows
Host Plants	Fennel, Parsley, Dill	Parsley, Dill, Carrot

Conclusion

The Anise Swallowtail is a remarkable creature that is not only beautiful but also plays a vital role in the ecosystem. Its stunning appearance, diverse habitat preferences, and unique life cycle adaptations make it a species worth protecting and preserving for future generations.

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Readers’ Mail

Over the years, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these butterflies. Scroll down to have a look at some of them.

Letter 1 – Life Cycle of the Anise Swallowtail

Ed. Note:  Our editorial staff will be on holiday for a few weeks, so we are post-dating submissions to go live during our absence.  We hope you enjoy this gorgeous series of images of the life cycle of the Anise Swallowtail

Subject: West Los Angeles sighting – Anise Swallow Tail #1
Location: West Los Angeles
June 1, 2017, 12:19 pm
Hi Daniel,
Here are the first of the sets of pictures you asked me to trickle in. Since I can attach only 3 images, I’m going to send in 4 sets for the swallowtail. If this is too much, please let me know.
Hope you enjoy these.
Signature: Jeff Bremer

Thanks Jeff,
We will put together a nice life cycle posting with the images you have sent.  We will distill them down to the best images and we will postdate your submission so it goes live during our absence mid-month. 

We feel we have to provide you with a challenge though.  Your spectacular life cycle images are lacking critical two stages. 

We hope someday you can capture the actual emergence of the adult from the chrysalis, and of course, we always love to post images of mating insects on our Bug Love page.

Newly hatched Anise Swallowtails somewhat resemble bird droppings which may help to camouflage them from predators.

As they grow and molt, later instars of the Anise Swallowtail Caterpillar take on the characteristic green color with black and yellow spots.

When threatened, the Anise Swallowtail Caterpillar reveals its osmetrium, a forked orange organ that releases a foul smell to deter predators.

As pupation time nears, the Anise Swallowtail Caterpillar spins a silken girdle to help keep it from hanging down.

This Anise Swallowtail Chrysalis is being visited by a parasitoid Chalcid Wasp.  Here is a posting from BugGuide that shows a close-up of the Chalcid Wasp.  Butterfly Fun Facts has an excellent description of this Parasitoid, including: 

“A healthy chrysalis will have light membranes between its abdominal segments. As wasps grow inside the chrysalis, the membranes turn dark.  Infected chrysalises turn darker and often have a reddish tinge to them. 

Remember! When a chrysalis is first infected (eggs laid in the chrysalis) it will appear healthy, have the correct colors and shades, and will move normal. Once the wasp larvae have grown for a few days, the color of the chrysalis will darken. 

A chrysalis that has a mature butterfly inside it will also turn dark the day before the butterfly emerges. If a butterfly is inside, you will see the wing pads the day before the butterfly emerges. If it darkens and wing pads cannot be seen, it is a danger sign.” 

Unfortunately, a percentage of Swallowtail Chrysalides will never produce an adult if they are preyed upon by parasitoid Chalcid Wasps.

The Anise Swallowtail Chrysalis darkens just before an adult is ready to emerge.

This is a gorgeous, adult Anise Swallowtail.

And the cycle begins anew as a female Anise Swallowtail deposits her eggs on the host plant.

Letter 2 – Anise Swallowtail: Why are the Butterflies Deformed???

Deformed Butterflies
Location: West Los Angeles
May 7, 2012 11:13 am
Hi Bugman,
Summer came late here in 2010. When it arrived, so did the butterflies. However, it didn’t last long and when the cold weather hit, we lost over 3 dozen chrysalis’. Some that did emerge had deformed wings.

They could barely fly or not fly at all.
I’m afraid history may be repeating itself as an Anise Swallowtail recently emerged with one deformed wing. It could fly, but with great difficulty.
Just thought I’d pass this on.
Jeff
Signature: Jeff Bremer

Hi Jeff,
Thanks so much for sending in your letter.  We suspect both environmental factors and genetic factors can contribute to deformed butterflies.  It would be curious to find out if anyone else is experiencing this phenomenon.

Letter 3 – Early Instar, Anise Swallowtail Caterpillar

The wild anise was growing nicely in the canyon, and we noticed the adult Anise Swallowtails flying about, so we decided to look to see if we could find any caterpillars.

We found three on one plant, barely 1/4 inch long, and assume they are Papilio zelicaon. We have never seen specimens this small and are unable to locate any photos to see if we are correct.

We will keep an eye on them and hopefully document their growth.

Letter 4 – Anise Swallowtail Rescue Mission!!!!!

Anise Swallowtails and their larva
Hi!
It might be unusual for you guys to receive pics of already-identified beasties, but I do actually have a question for you. We were delighted to encounter a pair of Anise Swallowtail larvae in a jar at a store in Berkeley (called The Bone Room), and so we acquired them (for $2 each).

The furry, attractive guys chewed away at their sprig of anise with great rapidity. We went on an expedition to locate additional food sources. A gigantic open parking lot at the hospital up the street was overgrown with anise.

There we harvested fresh food… and looked for more caterpillars. After a while, we began to spot them and came back with a couple more.

A few days later we went for more anise, and noticed that the hospital was engaging in a campaign of brush-clearing… several stands were now eradicated, chewed up, and temporarily stored in plastic garbage bags (we hope they were at least headed for composting, but even that seemed unlikely).

At that point, we realized any caterpillars anywhere in the lot that we failed to rescue were doomed. Over the next three weeks, we eventually accumulated 19 caterpillars.

We found them in each of their five instars, although the majority were noticed in the second instar. They are gorgeous and we enjoyed them greatly.

I have very large (32 oz) plastic cups with special lids which I use for fruit fly cultures, so those were repurposed as caterpillar enclosures. They seemed to work well. Eventually, we had 19 chrysalises.

After less than two weeks, the first chrysalis opened, and we had our first Anise Swallowtail! When we found it, its wings were still crumpled up. We moved it outside, putting it on some moss in the shade.

After running errands, we found it still there hours later – its wings fully erect, but not moving much. It was gently relocated to the Nasty Urshums (so my mother calls Nasturtiums) in the sunshine, and I captured a few pics… it flexed its wings several times in the warm sun, and then flew off!

I can’t tell you how wonderful it was to see that. Hand-raised swallowtails! We have since had five adults emerge, all within two weeks of the first.

Here is the question: it’s now been around 7 or 8 weeks since the last one emerged… we still have over a dozen chrysalises.

Some are bright green, and some are a dull brown woody color – this seems not to matter, as both kinds had successful adults before. So, what gives? Why are these ones not hatching? Are they dead?

We did have one that was definitely dead – it didn’t successfully attach to a stem or the wall or roof of the cups, and we found it blackened and rotting a couple of weeks ago in some accumulated moisture at the bottom of the cups.

This has not happened to the rest though. Looking at the browner chrysalises, it’s hard to imagine there is still a alive insect inside… but I know well that looks can be deceiving. We have had much warmer weather lately.

Could this be a factor? (our house is not air-conditioned, so it has gotten just as warm inside as outside). Could some be hibernating? If so, why would some hibernate while others seemed perfectly satisfied to emerge in the normal allotted time?

I thank you for whatever help you can provide… and attach a scan of my best photo of the first adult as a reward. I took this with my Canon AE-1, with Kodak 400, in bright sunlight at around 250 or 500 shutter speeds in shutter-priority program mode.

I used my Vivitar 28-105mm (f2.8-3.8) zoom lens in macro mode. The pic has been level-corrected, color-corrected, and the contrast adjusted in Photoshop, as well as reduced in size for suitable e-mailing and web posting.

Thanks
Josh

Hi Josh,
All we can suggest is to be patient. Nature has a way of ensuring survival by not having all plants sprout at the same time, and this might also apply to metamorphosis.

Letter 5 – Parsley Worms

i can have parsley.
September 14, 2009
I was at my Grandmother’s today and I grabbed a quick shot of these guys chowing down.  I believe I’ve correctly identified them via your site (because your description specifically mentions parsley!)

I hope you like this group shot of what I believe are Anise Swallowtail Caterpillars.
iPhone photo:
Here’s my Flickr entry:
Thanks for maintaining such a great site,
Casey

Hi Casey,
Since you did not provide a location, we are not certain if these are Black Swallowtails or Anise Swallowtails.  The caterpillars look very similar and both will feed on parsley. 

If you live in the central to eastern states, these are Black Swallowtails.  If you are west of the Rocky Mountains, they are Anise Swallowtails.

Thanks.
I live in Georgia so they would be Black Swallowtails.
Thanks, guys.

Letter 6 – Anise Swallowtail: Caterpillar molts to Chrysalis and Imago images

Anise Swallowtail
Location:  Cotati, CA
July 28, 2010 7:04 pm
I raised Anise Swallowtail butterflies locally for 15 years and have always had an amazing time watching them transform. I caught one of them in the middle of cocooning. Thought it would be nice to share! He later hatched into a beautiful butterfly!
Lauren

Hi Lauren,
Your photographs are stunning.  We especially like that your Anise Swallowtail Chrysalis photo has captured the molting process and the exoskeleton of the caterpillar is still visible.

Letter 7 – What’s That Caterpillar: Anise Swallowtail Caterpillar

Subject: What’s that Caterpillar?
Location: Southern California
July 13, 2012, 7:15 pm
I just went out to my mom’s standing garden to find three of these! I’m confused as to what they are because I’ve never seen them before. We’ve had plenty of tomato/horn worms and inchworms, but never these.

Signature: Dani F.

Hi Dani,
We love playing What’s That Caterpillar? with our readers.  We are guessing your mother has carrots, parsley, dill, or some other umbelliferous herb or vegetable growing in her garden, or else there is wild anise somewhere nearby, also a plant that has flowers in the shape of an umbel. 

This is the caterpillar of the Anise Swallowtail, a pretty black swallowtail butterfly with yellow spots.

Letter 8 – Probably Anise Swallowtail Caterpillar

Subject: unidentified caterpillar
Location: Houston, tx
July 14, 2014 8:53 am
Hi. Found a bunch of these guys yesterday eating my anise plant and nothing else.
People are calling them monarchs, but, I do not agree.
Your input would be most interesting.
Signature: Angela Gumerman

Dear Angela,
You are correct to recognize that this is not a Monarch Caterpillar.  It is a Swallowtail Caterpillar, and considering the Texas location and the anise food plant, it might be the caterpillar of an Anise Swallowtail, Papilio zelicaon, though BugGuide does not report the species as far east as Texas. 

The caterpillar of the Black Swallowtail, Papilio polyxenes, looks very similar and it has a more eastern range, though BugGuide lists food plants as: 

“Larvae feed primarily on plants of the carrot family (Apiaceae = Umbelliferae), and some in the Rue Family (Rutaceae). Commonly found on Dill, Parsley, Fennel, Carrot, and Rue in gardens, and Queen-Anne’s-Lace, Poison Hemlock, and Lovage in the wild. They will occasionally be found on Citrus trees”, we believe they will also feed on anise.

Letter 9 – Anise Swallowtail in Mount Washington

Subject:  Anise Swallowtail on Lilac
Geographic location of the bug:  Mount Washington, Los Angeles, CA
Date: 06/05/2018
Time: 11:00 AM EDT
From the window this morning, Daniel thought he saw a Giant Swallowtail on the last bloom on the lilac bush, but upon getting closer with a camera, he was excited to see it was an Anise Swallowtail.

After getting a few initial images, the Anise Swallowtail alighted on the avocado tree, allowing for a somewhat obstructed view of the ventral surface of the wings.

Letter 10 – Bug of the Month June 2020: Ovipositing Anise Swallowtail

Subject:  Yellow or Anise Swallowtail
Geographic location of the bug:  West Los Angeles
Date: 05/14/2020
Time: 05:47 PM EDT
Your letter to the bugman:  Hi Bugman,
Is this a yellow swallowtail or an anise swallowtail (or are they the same)? She’s laying her eggs on a fennel plant.
Thanks,
How you want your letter signed:  Jeff Bremer

Dear Jeff,
Please forgive our tardy response.  According to Jeffrey Glassberg’s book Butterflies Through Binoculars The West, the Anise Swallowtail has both a dark and a light or yellow form, and they are not designated as distinct subspecies.

 The two color forms exist over much of the species’ range.  According to BugGuide, there are two subspecies and BugGuide notes: 

“There has been a lot of debate over the years as to whether the inland populations of P. zelicaon are different enough to consider as a distinct subspecies from ‘typical’ zelicaon from closer to the Pacific. Also, it is debated, assuming there is a difference, just what the difference is, and where one population begins and the other ends.” 

We always appreciate your butterfly submissions and we are tagging this submission of an Anise Swallowtail as our Bug of the Month for June 2020. 

As a side note, Daniel was excited to find a young Anise Swallowtail caterpillar on a dill umbel in his garden and he watched it grow over the course of a week, only to have it vanish. 

The suspected culprit is a Paper Wasp seen patrolling the dill plant the day the caterpillar vanished.

Letter 11 – Newly Eclosed Anise Swallowtail

Subject:  Emerging Anise Butterfly In Trouble
The geographic location of the bug:  West Los Angeles
Date: 08/12/2021
Time: 12:14 PM EDT
Your letter to the bugman:  Hi Bugman,
I’m honored and humbled by your awarding me the Bug Humanitarian Award. And will endeavor to live up to it.

This morning, an Anise Swallowtail emerged from his chrysalis.  It seemed to me unusual that the chrysalis was formed on the fennel plant on which he hatched and fed, so I’ve kept an eye on him.

This was fortunate as the fennel plant has so many crisscrossing branches that there was not enough room for his wings to hang down and stretch out.
So I gently moved him to a better location and his wings did seem to hang properly. I hope it isn’t too late.

By the way, I’ve called this butterfly him because of his small size. The females I’ve seen ovipositing were much larger. Is this assumption correct?

Thanks,
How you want your letter signed:  Jeff Bremer

Hi, again Jeff,
In our experience with Eastern Tiger Swallowtails, the female is generally larger, and it is entirely possible the same is true for other Swallowtails.