Choosing the Right Host Plants for Giant Swallowtails

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The giant swallowtail butterfly, scientifically known as Papilio cresphontes, is a striking and exotic-looking species abundant in various regions such as Florida. These remarkable butterflies depend on specific host plants to lay their eggs and for their caterpillars to feed on. Understanding the ideal host plants for giant swallowtails is crucial for butterfly enthusiasts and gardeners who wish to attract and support these beautiful creatures.

Native host plants for giant swallowtail caterpillars usually come from the citrus family, Rutaceae. Examples of these host plants include orange, lemon, and lime trees. Additionally, they also feed on non-citrus plants such as Prickly Ash (Zanthoxylum americanum) and Common Rue (Ruta graveolens). Carefully selecting and incorporating these host plants in your garden can significantly increase the chances of attracting and nurturing giant swallowtails.

It is important to remember that while planting host plants, one must also consider the overall health of the plant, its compatibility with the surrounding environment, and how it will impact the local ecosystem. Choosing the right combination of host plants will not only benefit the giant swallowtail population but also contribute to a balanced and thriving garden ecosystem.

Giant Swallowtail Butterfly Basics

Appearance and Wingspan

The Giant Swallowtail butterfly (Papilio cresphontes) is known for its striking and exotic appearance. With a wingspan ranging between 4 to 6¼ inches, it is generally the largest butterfly in North America. Its wings exhibit a diagonal band of yellow spots, and the tails are edged with black and filled with yellow.

Life Cycle

  • Eggs: Giant Swallowtails lay eggs on host plants like citrus trees, prickly ash, and common rue.
  • Larvae (Caterpillars): The larvae feed on their host plants. The caterpillar stage lasts for three to four weeks.
  • Adults: Swallowtail butterflies have a lifespan of one to two weeks as adults.

More information on the life cycle can be found here.

Habitat and Distribution

Giant Swallowtails are found mostly in the southeast of the United States, including Florida. Their habitat varies across locations, from citrus tree groves to more diverse ecosystems. When planning a garden to host Giant Swallowtail larvae, it is encouraged to incorporate native plants such as pipevines, pawpaws, and spicebushes to ensure a proper environment for all stages of the life cycle, as can be seen in North Carolina State University’s host plant recommendations.

Comparison Table: Host plants for Swallowtail caterpillars

Butterfly Host Plant
Giant Swallowtail Citrus trees, prickly ash, common rue
Pipevine Swallowtail Pipevines (Aristolochia spp.)
Zebra Swallowtail Pawpaw (Asimina triloba)
Black Swallowtail Parsley family (parsley, dill, fennel, etc.)

Host Plants and Nectar Sources

Citrus Family

The giant swallowtail butterfly is attracted to plants in the citrus family. They lay their eggs on:

  • Citrus trees
  • Wild lime
  • Hercules club

Citrus is their preferred host plant, and caterpillars feed on tree leaves, causing damage to young trees.

Rue and Other Garden Plants

Ruta graveolens, known as rue, is another common host plant. Additional garden plants favored by swallowtails include:

  • Milkweed
  • Torchwood
  • Photinia

These provide both food for the caterpillars and nectar sources for the adult butterflies.

Native Trees

Swallowtail caterpillars also consume leaves of native trees, like:

These native trees serve as important host plants for the giant swallowtail population.


Giant swallowtails visit a variety of flowers for nectar. Some examples:

  • Butterfly bush
  • Lantana
  • Joe-Pye weed
  • Zinnias

Incorporating these flowers into your garden can attract more giant swallowtails.

Host Plants Caterpillars Feed Adult Nectar
Citrus Family Leaves of citrus trees Flowers
Garden Plants Milkweed, torchwood Photinia
Native Trees Tulip tree, prickly ash N/A
Flowers N/A Various types

Giant Swallowtail Caterpillar

Eggs and Larval Stages

Giant swallowtail caterpillars go through several stages in their lifecycle:

  • Eggs are laid singly on host plants
  • The eggs eventually hatch into larvae
  • Larvae go through multiple growth stages, called instars
  • Pupation occurs before transforming into adult butterflies

The giant swallowtail caterpillar typically passes through five instars before pupating.

Camouflage and Defense Mechanisms

Caterpillars are known for their incredible ability to blend into their surroundings. Giant swallowtail caterpillars use a unique strategy:

  • Resemble bird droppings to avoid predation
  • Swallowtail caterpillars blend in with the foliage on host plants

These methods reduce the chances of being detected by predators.

Food Preferences and Host Selection

Several factors play a role in giant swallowtail caterpillars’ food choices and host plant selection:

  • They primarily feed on plants from the citrus family (Rutaceae)
  • A good example is the Hoptree (Ptelea trifoliata)
  • Native plants are preferred, as they’ve adapted to the caterpillar’s requirements

Here’s a comparison of host plants commonly chosen by giant swallowtail caterpillars:

Plant Family Caterpillar Preference
Hoptree Rutaceae High
Citrus trees Rutaceae Moderate
Non-native plants Varies Low

Giant swallowtail caterpillars are more likely to thrive when provided with a suitable environment and host plants. Understanding their lifecycle, camouflage strategies, and food preferences can help create a suitable habitat for these fascinating creatures.

Other Swallowtail Species and Their Host Plants

Black Swallowtail

The Black Swallowtail caterpillar feeds on various herbs from the Apiaceae family, such as:

  • Queen Anne’s Lace
  • Dill
  • Parsley
  • Fennel

These plants provide an excellent environment for the growth and development of the caterpillars 1.

Eastern Tiger Swallowtail

Eastern Tiger Swallowtails have a diverse range of host plants that mainly belong to the Magnoliaceae and Rosaceae families. Some common host plants for Eastern Tiger Swallowtails include:

  • Tulip trees
  • Cottonwoods
  • Willows

These tree species provide a suitable habitat for the larvae to develop 2.

Spicebush Swallowtail

The Spicebush Swallowtail feeds primarily on the Spicebush plant, but it can also utilize other plants like:

  • Camphor
  • Sweet Bay
  • Tulip tree

These plants support the growth and transformation of the caterpillar into an adult butterfly 3.

Pipevine Swallowtail

Pipevine Swallowtails often prefer plants from the Aristolochiaceae family, mainly Pipevines, as their host plants. Other suitable host plants include 4:

  • North American Prickly Ash (Zanthoxylum clava-herculis)
  • Common Hoptree (Ptelea trifoliata)

These host plants provide a conducive environment for the larval stage of the butterfly’s life cycle.

Zebra Swallowtail

The Zebra Swallowtail caterpillar thrives on host plants from the Asimina species, primarily Pawpaw plants. In the deep South, other Asimina species like the Smallflower Pawpaw (Asimina parviflora) are also utilized as host plants 5.

Comparison Table:

Swallowtail Species Host Plants
Black Swallowtail Queen Anne’s Lace, Dill, Parsley, Fennel
Eastern Tiger Swallowtail Tulip trees, Cottonwoods, Willows
Spicebush Swallowtail Spicebush, Camphor, Sweet Bay, Tulip tree
Pipevine Swallowtail Pipevines, North American Prickly Ash, Common Hoptree
Zebra Swallowtail Pawpaw plants, Smallflower Pawpaw

Attracting Giant Swallowtails to Your Garden

Choosing Host Plants

Giant Swallowtails primarily lay their eggs on wild lime and citrus plants. Another host option is the Hoptree (Ptelea trifoliata).

  • Wild Lime: Native plant, easy to grow
  • Citrus Plants: Lemon, orange, and grapefruit trees
  • Hoptree: Blooms in spring, produces wafer-shaped fruit

Providing Nectar Sources

Giant Swallowtails and other pollinators need nectar sources like flowering plants. Good options include:

  • Milkweed: May take a couple seasons to produce flowers (source)
  • Rattlesnake Master: Unique blue-green leaves, attracts many pollinators (source)
Nectar Source Pros Cons
Milkweed Native, attracts monarchs Slow flowering
Rattlesnake Master Unique appearance Not well-known

Creating a Butterfly-Friendly Environment

To support Giant Swallowtail and other pollinators, pay attention to:

  • Access to water: Create spots with shallow water or mud puddles
  • Shelter: Provide trees and shrubs for resting and hiding
  • Sun exposure: Plant flowers in sunny locations, as butterflies prefer sun

Lastly, regular maintenance like weeding and watering will keep your garden healthy, attracting more pollinators (source).

Giant Swallowtail Predators

Common Predators

Giant swallowtail butterflies (Papilio cresphontes) can fall prey to various predators, such as:

  • Birds: Birds are the main predator of swallowtail butterflies, including adult and caterpillar stages.
  • Spiders: Many spiders, such as orb-weavers, feed on adult butterflies caught in their webs.
  • Insects: Some parasitic wasps and flies lay eggs inside caterpillars, killing them when their larvae hatch and feed.
  • Snakes: Certain snake species may feed on swallowtail caterpillars.
  • Osmeterium: This unique defense organ found in swallowtail caterpillars releases a foul-smelling substance to deter predators.

Protecting Giant Swallowtails from Harm

To keep your giant swallowtails safe from harm, consider the following precautions:

  • Provide cover: Plant dense foliage, such as shrubs and tall grasses, to provide hiding spots for butterfly larvae and adults.
  • Reduce pesticide use: Many chemical pesticides also kill beneficial insects that help control pests, inadvertently leaving giant swallowtails more vulnerable.
  • Encourage natural predators: Birds, beneficial insects, and snakes can help control pest populations and protect swallowtails by eating other insects that would otherwise harm them.
  • Install bird netting: Placing a fine mesh net over host plants may help protect caterpillars from bird predation.


  1. Black Swallowtail – Papilio polyxenes asterius
  2. Swallowtails – The Butterflies of North America
  3. Spicebush Swallowtail – Papilio troilus
  4. Pipevine Swallowtail – Battus philenor
  5. Zebra Swallowtail – Entomology and Nematology Department

Reader Emails

Over the years, our website, 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 – Orange Dog

Bug found on Lemon Tree in AZ
May 2, 2009 at 12:57 PM
We found this bug on a leaf of our Lemon Tree. What is it? Is it harmful to humans? Is it harmful to the tree or other vegetation? Do we need to spray the tree or other plants?
SW – Scottsdale, AZ

Orange Dog
Orange Dog

Hi Stan,
This is the caterpillar of a beautiful butterfly, the Giant Swallowtail.  The caterpillar is commonly called an Orange Dog and it mimics bird droppings to avoid getting eaten.  The caterpillar will eat some leaves, but will do no lasting harm to your tree.  You should not spray your tree because of the Orange Dog.  The Orange Dog is not harmful to humans, but if you provoke it, you will be treated to seeing the osmetrium emerge.  The osmetrium is a scent organ resembling two orange horns and it gives off an odor to repel its attacker.

Letter 2 – Giant Swallowtail Caterpillars in New York

Subject: Raising Bufferflies (we hope!)
Location: Halfmoon, NY (near Albany)
June 24, 2012 9:53 am
I came across your website while trying to figure out what type of caterpillars took over our rue. Last year we successfully raised and released over 30 Monarchs and this year have decided to rescue other caterpillars. We found these just after they hatched and thought they were Black Swallowtails as we had already found a large Black Swallowtail caterpillar (now in it’s chrysalis). As we watched them grow, we realized that we had been mistaken. Are these Giant Swallowtail caterpillars? We are hoping that we have enough rue to sustain our 6 new rescues!
Signature: Sarah

Giant Swallowtail Caterpillar on Rue

Hi Sarah,
We must commend you on your successful identification of this Giant Swallowtail Caterpillar and we wish you luck with the raising of it and its siblings to the butterfly stage.  Giant Swallowtails are a native species, but their range has expanded considerably and their numbers have increased in portions of the range where citrus is cultivated.  Though citrus is not native, the caterpillars adapted to feeding on the leaves of orange and other citrus trees, earning the caterpillars, which resemble bird droppings, the name Orange Dog.  We did locate a note on the All the Dirt on Gardening website that states:  “Rue gets special treatment in our garden is because it is the only plant we grow that is used by Giant Swallowtail butterflies to raise their caterpillars. Rue’s poisonous leaves make the caterpillars taste bitter to predators so they are left alone.”  We believe the website originates in Canada.

Letter 3 – Orange Dog

What is this?
October 16, 2009
We found this on a dwarf orange tree in our yard today (October 16, 2009) and would like to know what it is. It had apparently eaten half a leaf in the morning. In the evening it was on another leaf, which it had begun to consume. It move it’s head vertically when I first moved my hand toward the leaf upon which it perched. We would love to know what it is. Thank you!
Dr. TJ
San Diego, CA

Orange Dog
Orange Dog

Dear Dr. TJ,
This is an Orange Dog, the caterpillar of the spectacular Giant Swallowtail.  We gladly sacrifice a few leaves on our citrus trees to be able to enjoy this beautiful butterfly in our garden.  The resemblance of the Orange Dog to bird droppings is a camouflage mimicry device.

Letter 4 – Giant Swallowtail in New Hampshire

Subject: Giant Swallowtail in NH?
Location: Francestown, NH
August 6, 2012 9:05 pm
I saw this butterfly the other day and I don’t remember seeing this around before. Looks like a Giant swallowtail from other pictures I’ve seen.
Is it unusual for this to be found here in Southern NH? Was wondering if it was due to the rediculously warm winter or if it’s just a random thing.
Signature: Alf

Giant Swallowtail

Hi Alf,
This certainly is a Giant Swallowtail.  Though southern sightings are more common, northern sightings do occur.  BugGuide has received submissions of Giant Swallowtails from New York, Massachusetts and Ontario.  Prior to the introduction of citrus crops in the south, the native larval food source was the common pricklyash,
Zanthoxylum americanum, as well as the common hoptree, Ptelea trifoliata.  The USDA Natural Resources Conservation Service Plant Database has a map of the range of the common hoptree and it stretches considerably further north than New Hampshire.  The USDA website has a similar map for the common pricklyash.  BugGuide also states that Giant Swallowtails can stray as far north as “Nova Scotia, Quebec, Manitoba, and North Dakota.”  The common hoptree and common pricklyash are not found in Arizona or California, however, the range of the Giant Swallowtail has expanded to the west coast thanks to the cultivation of citrus.  The caterpillars of the Giant Swallowtail are commonly called Orange Dogs.

Giant Swallowtail

Letter 5 – Giant Swallowtail in Pennsylvania

Black butterfly with yellow stripes?
Location: Doylestown, Pennsylvania
December 5, 2011 8:59 am
Hey there.
I’ve been lurking your site for awhile and appreciate your extensive knowledge of bugs.
Awhile back I came across a black butterfly with yellow stripes. I have not seen very many pictures of it online and I was wondering what it was. I’ve been told it was an Eastern Tiger Swallowtail but almost none of the pictures look like this guy.
Signature: Mister Sergei

Giant Swallowtail

Dear Mister Sergei,
Though they are found as far north as Canada, Giant Swallowtails,
Papilio cresphontes, are much more common in the southern portions of their range where they have adapted to an introduced larval food plant, the leaves of citrus trees.

Letter 6 – Giant Swallowtail in Tennessee!!!

Giant Swallowtail
June 25, 2010
Hi Daniel, This beautiful butterfly was shot about three weeks ago. I was driving down a country road, when I saw it I had to stop and back up a few feet to shoot from the car window. I thought it was an “Eastern Tiger Swallowtail” but it has been bothering me because the marking were different I thought it might be a mutant. Then tonight I followed a link you had to “Butterflies and Moths of North America” lo and behold their it was just as big as life. (Wonderful site also) I was impress with the beauty of this one and with your help,permission and tolerance I would like to share it with everyone. Thank you and have a wonderful day.
North Middle Tennessee

Giant Swallowtail

Hi again Richard,
We will never forget the first time we saw a Giant Swallowtail in Los Angeles in the first years of the new millennium.  around the time they became more plentiful in Southern California.  They frequently visit our lantana beginning in July.  We have read in numerous places that this is the largest North American butterfly.  the LA Times did a nice story in 2007.

Letter 7 – Giant Swallowtail Metamorphosis

Giant Swallowtail (Papilio cresphontes) developmental series
Hi Lisa Anne and Daniel,
Glad to see that you are keeping up your great work with your website. Last year I submitted some picture series about the development of butterflies. This year I would like to share my Giant Swallowtail shots with you.

I found 6 caterpillars on Prickley Ash during the summer in Wisconsin, and breeding this species is a wonderful experience. My girlfriend Megan will be delighted to see “her” caterpillar on your page, which she got as a present from me to encourage her slightly increasing interested in bugs. Keep up the great job! Best wishes from Madison/Wisconsin,
Thomas Werner

Hi Thomas,
Thanks for sending us your wonderful Giant Swallowtail metamorphosis images.

Letter 8 – Giant Swallowtail: newly emerged

One I know, one I don’t
Here are a couple of pics of critters from my back yard in Debary, FL (Central Florida) The butterfly, an Old World Swallowtail, was only minutes to hours old when I snapped the photo – not sure how long they take to fly. He came home with us from a nursery yesterday on the Key West lime he’s hanging from in the picture. He was stretching out his still soft wings this morning when I took the picture and was gone an hour after this photo. The other pic is of a very small spider I’ve never seen before. The leaf he’s on is Thai Basil and is no more than an inch long. Do you know this little guy?

Hi Alex,
The butterfly you have identified as an Old World Swallowtail is actually a Giant Swallowtail, Papilio cresphontes. Key Lime is a larval food plant for the caterpillars which are known as Orange Dogs. We would need more time to identify your spider which is one of the Orbweavers.

Letter 9 – Giant Swallowtail sighting in Ann Arbor, Michigan

Subject: Butterfly in Ann Arbor, MI
Location: Ann Arbor, MI
September 21, 2014 10:52 am
I took these pictures on my phone in August at the Nichols Arboretum in Ann Arbor, MI. I just moved to the area so I’m not yet familiar with its wildlife. I have seen lots of black swallowtail caterpillars and butterflies this August and September but I’m not sure if this butterfly is one as well. It doesn’t seem to have the blues, yellows or reds… and it has a band of that white-ish yellow color across its hindwing that I haven’t seen before.
It may have a swallowtail wing shape – I can’t tell. But something interesting about its wings is that it seemed to fold the forewing somewhat independently of the hindwing. I tried to include a picture showing that, but it was hard to catch.
Thank you!
Signature: Butterfly Observer

Giant Swallowtail
Giant Swallowtail

Dear Butterfly Observer,
The Giant Swallowtail, a native species, has adapted as a caterpillar, called an Orange Dog, to eating the leaves of imported and cultivated citrus trees, and its range has expanded where citrus is grown.  Consequently, it is now more common in the southern portion of its range including Florida, and the expanded western regions all the way to the Pacific Ocean.
  We imagine your Michigan sighting is not a common occurrence.

Wow!!! I’ve heard the name Giant Swallowtail before but I didn’t even know what they look like and I don’t think I’ve ever seen one. How exciting! I’m glad I asked you guys. I really love your site- thanks for the work you do!

Letter 10 – Giant Swallowtail visits WTB?

Subject:  Giant Swallowtail
Geographic location of the bug:  Mount Washington, Los Angeles, California
Date: 04/20/2018
Time: 011:20 AM EDT
This morning from the window, Daniel noticed this Giant Swallowtail land in the meadow out front.  Daniel has learned through the years to get a shot quickly before fine tuning adjustments and camera angle, and sure enough, as he moved closer for a better angle, this beauty flew off.  If memory serves us correctly, Giant Swallowtails, which are native to the eastern United States, first appeared in Los Angeles around 1998.  Cultivation of citrus trees and the adaptation of citrus trees as an acceptable food for the caterpillars have led to this significant range expansion.

Giant Swallowtail

Letter 11 – Orange Dog

our baby dragon
My girlfriend and I have been feeding this little fella for a couple days. He seems only to like the leaves from her equally beloved lemon tree, however, and not the ones from any of the other flora. I’m surprised he hasn’t been eaten by any of the many birds that sit in the flower bed where we have him housed here in Southern California. We are just so grateful to have a bug friend that isn’t a @#$@#%@# spider, that we’re quite attached. Would love to know what he is though. As you can see, he’s got a caterpillar kind of body and then almost a fake head. And if you bug him a little (heh), he sticks out what looks like a red forked tongue (also pictured). Thanks for your help. Definitely thought I was in the running for weirdest bug in the neighborhood ’till I browsed your site a little.

Hi D,
The common name for your caterpillar is the Orange Dog because of its diet, often leaves from orange trees. Obviously, it also eats other citrus. This is the caterpillar of the Giant Swallowtail. Probably birds don’t bother it since the caterpillar has the appearance of bird droppings. Those orange horns are actually scent glands that give off a foul odor, another bird deterrent.

Letter 12 – Orange Dog

Tue, Nov 25, 2008 at 4:58 PM
Dear bugman,
My curiosity has overtaken me with what this beautiful catepillar will be born into. I found this specimen in Feb-Mar, in San Diego, on my doormat. Luckily we didn’t step on it. It was slow moving, as I played with it for a while before placing it back where I found it. It was about an inch long, smooth and soft. As you can see it prefers mimicry, hence the bird dropping look, yummy. I was just wondering if you could place a name on it. Thanks, love the site. Keep it up.
Chris, friend of all bugs
San Diego, CA

Giant Swallowtail Caterpillar
Giant Swallowtail Caterpillar

Hi Chris,
Your bird dropping mimic is the caterpillar of a Giant Swallowtail, Papilio cresphontes.  It is sometimes called an Orange Dog because it feeds on the leaves of orange and other citrus trees.  The butterfly is a lovely brown and yellow “tailed” species.  In recent years, the Giant Swallowtail has expanded its range to include much of Southern California.

Letter 13 – Orange Dog

Alien Worm on my Orange Tree
June 3, 2010
Strangest worm looking creature with a sort of shell and retracting antenna was on my orange tree this morning. I put it in a jar with the leaf, and it ate some of the leaf.
any way you like
Lutz, FL zip code 33549

Orange Dog

Dear any way,
This is the caterpillar of a Giant Swallowtail, a lovely brown and yellow butterfly with tails on the hind wings.  Commonly called an Orange Dog, this caterpillar avoids being eaten by birds because it resembles bird droppings.  The retracting antennae you mentioned are a scent organ knows as the osmetrium.  When disturbed, many Swallowtail Caterpillars reveal this organ which is accompanied by a scent thought to deter predators.  The sacrifice of losing a few leaves on your tree will reward you with an adult butterfly in the coming weeks.

Letter 14 – Orange Dog

Location:  central Florida
October 15, 2010 8:45 pm
I found these caterpillars eating the leaves on a small, very thorny bush, about 2’ tall on the side of a sandy road in Melbourne, FL. The caterpillars are very flat and not hairy, that I can see.
Signature:  Always curious

Giant Swallowtail Caterpillar

Dear Always Curious,
This is the caterpillar of a Giant Swallowtail which is commonly called an Orange Dog.  The caterpillar has several survival mechanisms, and one is that it appears to resemble bird droppings, thereby avoiding predators.

Thanks for the  giant swallowtail ID.   Your website is awesome!  Always curious

Letter 15 – Orange Dog

Caterpillar ID
Location: Scottsdale, Az
November 20, 2011 3:54 pm
We saw this insect at our home in Scottsdale, Az in early Nov 2011.
Signature: Stan

Orange Dog

Hi Stan,
This caterpillar that mimics bird’s dropping is commonly called the Orange Dog because it feeds on the leaves of orange and other citrus despite it being a native species and citrus being Mediterranean.  The Orange Dog will eventually metamorphose into a Giant Swallowtail,
Papilio cresphontes.  Though Giant Swallowtails are native to the southeastern U.S., they have more recently been reported in parts of the Southeast, including Los Angeles, CA, most likely because of the cultivation of orange orchards and accidental introduction from Florida or natural range expansion because of the availability of citrus to augment the native diet of ” Common Pricklyash (Zanthoxylum americanum), and Common Hoptree (Ptelea trifoliata)” according to BugGuide.

Letter 16 – Orange Dog

Subject: It’s a caterpillar!
Location: Los Angeles
August 14, 2012 6:12 pm
Update–(I wrote last week when it was a baby and I had NO idea what it was. It looked like a legless/tailless lizard)– Now that it’s 2.5+ inches long, I can tell it’s a caterpillar. Two weeks ago it was 1/2 inch long. It hasn’t moved more than a foot! It eats one leaf a night and moves on to the next one. He’s getting awfully big. When you agitate him, two orange spikes? antenna? pop out of the back of his head (2nd photo). I’ve spotted another baby one (3rd photo) – hoping they’re not detrimental to the orange tree. I’ve searched your archives and I can’t find another. Thanks for the help whatsthatbug!
Signature: caterpillar curious!

Orange Dog

Dear caterpillar curious,
This caterpillar will eventually metamorphose into a beautiful Giant Swallowtail and the caterpillar is commonly called an Orange Dogbecause it feeds on the leaves of orange and other citrus trees.  A few caterpillars will not harm a tree by eating a few leaves.  The Orange Dog has two main means of defense.  The method you noticed is that when disturbed, it produces a forked orange scent organ known as an osmeterium that releases an odor that some predators find offensive.  Also, when resting, the caterpillar resembles a bird dropping rather than the succulent morsel it actually is.

Orange Dog


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    Bugman aka Daniel Marlos has been identifying bugs since 1999. 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.

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    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.

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18 Comments. Leave new

  • how long will a giant swallowtail hibernate? i have 2 that i have indoors for 4 months in southern calif. now are outside.

  • as my sister put it “it smells like a wet dog that’s been peed on”.

  • carolyne shapiro
    June 30, 2014 12:56 pm

    I have been growing a lemon tree about three years now – just the other day I saw what looked to be a bird dropping on one of the leaves but to my surprise the thing moved!!! I do not know what it was doing but a big bubble came out of its mouth like it was giving birth which it might have been as a small – very small baby one then appeared on a leaf not far from – I cannot find the original one but the baby grew pretty darn big literally overnight – it is eating up some of my leaves but there are enough leaves for it to eat that I am not worried – does anyone know how long it takes to turn into a cocoon and then into a butterfly? It is by far one of the weridest and ugliest things I have ever seen but I do not know what to do with it -I don’t want to kill it but I really do not want it in my tree anymore either – have no clue how it is after three years where it came from – have never seen one before and I have four lemon trees – please if anyone has any answers – write to me at my e mail: I would be most appreciative – thank you!!!!! Carolyne

  • I have quite a few Orange Dog on my Lemon Tree. It does not bother me of eating few leaves. Is it OK to live it shop butterfly flies away or I need to get read of these. Please guide me as I do not like to kill Orange Dog if it is not harmful.

  • Linda Singleton
    September 6, 2014 6:07 am

    I have one onmy lemon tree. How long efore it turns into a butterfly. It is two inches long?

  • Thank you bugman – mine went away oddly. I am hoping all for the good. Have not seen another since. None of my other lemon trees have these strange little guys on them – just the big one who was eating thru my leaves at a rather rapid pace until he stayed still for a few weeks and then just disappeared. I am hoping he managed to turn into a butterfly. I have twp preying mantis’ now and am concerned a preying mantis certainly could have eaten him up which makes me sad. What is it that happens when it goes from the bird drop looking like thing into a cocoon? I am thinking it must look something like a large acorn?

  • when I first found this snake like creature I was mystified even somewhat horrified Does anyone know what the curious looking orange bodied fly is that hangs out near my caterpillars and what they are doing? Im assuming they are hanging around for the eggs? Any info would be appreciated.

  • thanks for all of the information, I had never seen one before and this morning found one on my orange tree.

  • Gotta admit, this is the ugliest of all. is there a way to get rid of them permanently or do we just have to ignore them? there must be some kind of a spray doesn’t there?

  • Francisco Hedio Mendes
    May 25, 2018 5:37 pm

    Legal!!!! Para que exterminar bichinho tão simpático, apesar de sua voracidade pelas folhas do Limoeiro. Tenho várias e não me incomodam em nada.

  • wow, 7 years and 2 months later and we finally saw an Orange Dog in the garden, amazing!

    • We are glad you located your old submission and posted this update on Giant Swallowtails in your garden. We are guessing the Orange Dog was not feeding on citrus in Hew Hampshire. BugGuide lists food plants as: “Larvae feed on leaves of plants in the Citrus family (Rutaceae), including Citrus (Citrus spp.), Pricklyash (Zanthoxylum spp.), Hoptree (Ptelea trifoliata), Rue (Ruta graveolens), etc.” On what plant was your individual feeding?

  • Dionne "Dee"
    April 25, 2020 9:18 am

    How long does it take for the Giant Swallowtail to complete its metamorphosis?

  • I went out today and found that my rue was pretty much stripped of its leaves. I had to fond out what I had helped survive…. Glad it’s a “good guy.” (I’m in MD.)


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