ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

The State Insect of Arizona: The Two-Tailed Swallowtail

Updated on March 26, 2019
fcmosher profile image

I'm a life-long naturalist and citizen scientist with a deep and abiding curiosity about the natural world.


The Big, Beautiful Two-Tailed Swallowtail

This huge butterfly -- the largest in the US -- closely resembles the tiger swallowtail (Pterourus glaucus). The two-tailed is limited to the US west of the Rockies, and even then is more common in the southern portion of that range. It floats like a kite high in the trees along streams and forest edges, coming down to feed at thistles and asters. I remember the first time I saw one, in the Coronado National Forest in Arizona, flying along a stream in the heat of a desert day. It is a truly magnificent insect, and deserves its status as the state insect of Arizona, a state with more than its fair share of cool insects in the first place.

Two-Tailed Swallowtail Showing its "Tails"


Papilio multicaudata

The scientific name of the two-tailed swallowtail indicates that it belongs to the genus Papilio, a large group of showy butterflies that often have tails on their wings. Early entomologists thought the tails resembled those of barn swallows, hence the common name. Papilio multicaudata is closely related to the widespread tiger swallowtail, as well as other yellow and black striped Papilio butterflies. It is limited in range to the southwestern United States, but will occasionally stray to central states, where it will typically not breed due to the cold temperatures of the winter months. The southern range of P. multicaudata extends all the way to Central America, where there are many, many Papilio species. Many of these tropical swallowtails are among the biggest and most beautiful butterflies in the world.

Two-tailed Swallowtail Caterpillar


Two-Tailed Swallowtail Caterpillar

The larva of Papilio multicaudata resembles that of the tiger swallowtail, a related species that is widespread throughout the United States. It feeds on chokecherry, ash, and Arizona sycamore, all common trees in much of the state. Most are green, but they turn red or brown before pupating. Note the fake "snake's eyes" on the front sections. Interestingly, the size of the fake eyes is much less important than the shape. In other words, as long as the markings look like eyes, they don't need to be particularly large. Predators will be unlikely to take the chance, no matter how big the "eyes."

Another Swallowtail Species Showing Enormous Fake Eyes

The spicebush swallotail, Papilio troilus, has striking eye-spot markings that may fool predators
The spicebush swallotail, Papilio troilus, has striking eye-spot markings that may fool predators

Unusual Features of Swallowtail Caterpillars

Like all Papilio species, the caterpillar of the two-tailed swallowtail has some unique features and behaviors. Most interesting is something called an "osmeterium." It's located right behind the caterpillar's head, and consists of an orange, forked gland that the caterpillar can stick out whenever it feels threatened. The osmeterium looks a lot like a snake's tongue, and is designed to scare off predators like birds and frogs. It also smells bad, a little like rotten fruit. All things considered, it's a pretty great defensive tactic.

Another feature of many swallowtail caterpillars is large false eye-spots near the head. The caterpillar's real eyes are tiny; the big ones are only markings. But combined with the osmeterium, the caterpillar can put on a pretty good "snake show."

Finally, swallowtail caterpillars typically construct a kind of "seat belt" when they pupate. This is a band of silk that supports the chrysalis (pupa) on the stick or twig. No other group of butterflies does this!

The Osmeterium in Action

Yellow and Black: Universal Warning Colors

The bright yellow and black colors of the two-tailed swallowtail are almost certainly a defensive feature designed to warn away predators. Black and yellow, red, or orange are the colors of stinging and otherwise protected insects, a way to advertise to potential predators like birds and amphibians, "stay way! I sting!" Butterflies don't sting, of course, but they may obtain some protection by flashing warning colors to fool a random toad into thinking twice before it tries to make the butterfly its lunch.

Next time you're in Arizona, keep an eye out for this beautiful butterfly!


The following sources were used for this guide:


    0 of 8192 characters used
    Post Comment

    No comments yet.


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)