Introduction:

The swallowtail butterfly family, Papilionidae, consists of at least 550 species, many of which are large and colorful and recognizable even to non-specialists. While the majority of swallowtail species are found in tropical latitudes, representatives from the family can be found on every continent except Antarctica, and can be common in both tropical and temperate habitats. Swallowtail butterfly diversity is greatest in East and Southeast Asia, a region where many natural butterfly habitats are under extreme threat of destruction due to human activity. Some swallowtails, particularly representatives from the genus Parnassius, may fly at very high elevations. The birdwing butterflies (Troidini: Troides) of Australasia are the largest butterflies in the world. Collins and Morris (1985) provide an overview of the patterns of swallowtail diversity around the world. 

 The name "swallowtail" refers to a tail-like extension on the edge of the hindwing that is found in many, though not all, papilionids. The function of this tail is not known, but genetic studies in some species of Papilio suggest the tail is a labile character whose expression is controlled by a single gene (Clarke and Sheppard 1960, Clarke et al. 1968). 

 Within the Papilionidae, many families of larval hostplants are utilized, although five families generally dominate the host records: Aristolochiaceae, Annonaceae, Lauraceae, Apiaceae, and Rutaceae. Notably, the swallowtail tribes Zerynthiini (Parnassiinae), Luehdorfiini (Parnassiinae) and Troidini (Papilioninae) are limited almost exclusively to feeding on Aristolochiaceae. It has been demonstrated in a number of Aristolochia-feeders that caterpillars are able to sequester aristolochic acids, causing both the larval and adult stages to be unpalatable to predators (eg. von Euw et al. 1968). 

Characteristics:

Three unambiguous morphological characteristics unite all papilionids and distinguish them from the other butterfly families. 

 

 
1. All swallowtail caterpillars possess a forked, eversible organ behind the head known as an osmeterium. The osmeterium secretes a foul-smelling terpene-based defensive compound (Eisner and Meinwald 1965). When molested, a caterpillar will evert its osmeterium and rear its head back in an attempt to dissuade its antagonist. The specific composition of osmeterial secretions may vary between swallowtail species. 

      

   Image copyright 2002 Felix A. H. Sperling

 
2. The second anal vein (vein 2A) on the adult forewing extends to the wing margin and does not converge with the first anal vein (vein 1A). In all other butterfly families veins 1A and 2A fuse, and 2A does not reach the wing margin.    

   Drawing modified from Miller 1987, copyright 2002 R. D. Reed

  
3. The cervical sclerites join beneath the neck.
 

Diversity description:

There are about 600 species of swallowtail butterflies (Scriber, 1984; Collings and Morris, 1985). These are generally recognized in three subfamilies: Baroniinae (a single species, Baronia brevicornis), Parnassiinae (recognized as 54-76 species in 8 genera), and Papilioninae (550 species in 17 genera)

The swallowtail butterfly family, Papilionidae, consists of at least 550 species, many of which are large and colorful and recognizable even to non-specialists. While the majority of swallowtail species are found in tropical latitudes, representatives from the family can be found on every continent except Antarctica, and can be common in both tropical and temperate habitats. Swallowtail butterfly diversity is greatest in East and Southeast Asia, a region where many natural butterfly habitats are under extreme threat of destruction due to human activity. Some swallowtails, particularly representatives from the genus Parnassius, may fly at very high elevations. The birdwing butterflies (Troidini: Troides) of Australasia are the largest butterflies in the world. Collins and Morris (1985) provide an overview of the patterns of swallowtail diversity around the world. 

 The name "swallowtail" refers to a tail-like extension on the edge of the hindwing that is found in many, though not all, papilionids. The function of this tail is not known, but genetic studies in some species of Papilio suggest the tail is a labile character whose expression is controlled by a single gene (Clarke and Sheppard 1960, Clarke et al. 1968).  

 Within the Papilionidae, many families of larval hostplants are utilized, although five families generally dominate the host records: Aristolochiaceae, Annonaceae, Lauraceae, Apiaceae, and Rutaceae. Notably, the swallowtail tribes Zerynthiini (Parnassiinae), Luehdorfiini (Parnassiinae) and Troidini (Papilioninae) are limited almost exclusively to feeding on Aristolochiaceae. It has been demonstrated in a number of Aristolochia-feeders that caterpillars are able to sequester aristolochic acids, causing both the larval and adult stages to be unpalatable to predators (eg. von Euw et al. 1968). 

Papilionidae (Swallowtail Butterflies)
These are large-sized butterflies. They are often black-and-yellow striped, or they are black with rows of yellow, blue, or red dots. The hindwings often have tails. Some species, such as the Battus philenor (Pipevine Swallowtail), are distasteful and toxic, while other species of swallowtail mimic this butterfly. The caterpillars tend to be smooth and green with markings from other colors. They have horn-like structures that appear when the caterpillar is disturbed, emitting a noxious smell. The caterpillars feed on a wide variety of plants, including members of the Carrot family, Wafer Ash and Prickly Ash, Spicebush and Sassafras, pipevines, wild cherries, and other trees. The pupae are angular-shaped, green or brown, and slung from a stem with a silk girdle.

Three unambiguous morphological characteristics unite all papilionids and distinguish them from the other butterfly families.

1. All swallowtail caterpillars possess a forked, eversible organ behind the head known as an osmeterium. The osmeterium secretes a foul-smelling terpene-based defensive compound (Eisner and Meinwald 1965). When molested, a caterpillar will evert its osmeterium and rear its head back in an attempt to dissuade its antagonist. The specific composition of osmeterial secretions may vary between swallowtail species.

   

   Image copyright © 2002 Felix A. H. Sperling

2. The second anal vein (vein 2A) on the adult forewing extends to the wing margin and does not converge with the first anal vein (vein 1A). In all other butterfly families veins 1A and 2A fuse, and 2A does not reach the wing margin.

   Drawing modified from Miller 1987, copyright © 2002 R. D. Reed

3. The cervical sclerites join beneath the neck.

There are over 550 species of swallowtails around the world. Most are tropical, only about 30 are found in the United States, and only 8 are in Michigan.

Biogeographic Regions: nearctic (Native ); palearctic (Native ); oriental (Native ); ethiopian (Native ); neotropical (Native ); australian (Native )

Geographic Range:

Nearctic, Palearctic, Oriental, Ethiopian, Neotropical, Australian

Geographic Range description:

Swallowtails have a worldwide distribution (Scriber, 1984; Collins and Morris 1985)

This family contains species that are the largest butterflies in North America. Swallowtails get their name from the "tails" on the back edge of their wings that reminded people of the forked tails of Swallows. Adults swallowtails have black or black and yellow/white wings, sometimes with additional blue or red markings. All Michigan species have the tails on their hindwings, but some species in other parts of North America don't have them.

Swallowtail caterpillars are large and smooth, but they have an orange "horn" that is hidden under the skin of the thorax. They pop it up when they are threatened by predators, and it gives off repellent chemicals. Young caterpillars are black with white spots, and look like bird droppings. As they get older they change color, then they are often green but with black or yellow stripes, and several species have large spots that look like eyes.

Some species of swallowtails are mimics of others that have toxic compounds in their bodies.

Other Physical Features: ectothermic ; bilateral symmetry

Sexual Dimorphism: female larger; sexes shaped differently

Texture:

smooth

Orientation:

upright

Egg mass pattern:

Usually laid singly on the foodplant, but occasionally in small clusters. Sometimes they are deposited near the foodplant rather than on it. (Scoble 1992)

Description of egg morphology:

Unsculptured and almost spherical.

Secondary setae:

present

Larval body description:

The body is sometimes smooth, but numerous secondary setae typically occur on the body (Scoble, 1992)

Crochet arrangement description:

The crochets are triordinal and, on the ventral prolets, arranged in a mesoseries. A weak, biordinal lateroseries may also occur on the ventral prolegs (Scoble, 1992)

Pupa description:

Typically exposed and attached to its substrate by a silken girdle traversing the thorax.

Cremaster:

present

Cocoon:

absent

Cocoon description:

In Parnassiinae, pupation occurs in a loose cocoon on the ground (Munroe, 1982)

Epiphysis:

present

Forelegs:

normal

Number of tibial spurs foreleg:

from 0

Number of tibial spurs midleg:

from 0 to 2

Number of tibial spurs hindleg:

from 2

Leg description:

foreleg is not reduced apart from the arolium and pulvilli

Forewing anal vein notation:

There are 2 anal veins that are united at the base of the wing but then diverge

Hindwing anal vein notation:

There is one anal vein

Forewing description:

From Scoble, 1992: "In the forewing R4 and R5 are typically stalked, CuP is usually present near the wing base.

Hindwing description:

From Scoble, 1992: "A humeral vein is present on the hindwing. Sometimes scent brushes occur in an anal fold of the male hindwing."

Eyes:

smooth

Maxillary palpus:

minute

Female antennae:

clubbed

Male antennae:

clubbed

Apomorphies:

All synapomorphies below are directly from Scoble 1992.  A protrusible, forked osmeterium occurs on the larval prothorax.  In the adult, the arolium and pulvilli of the pretarsus are reduced.  In the forewing, vein 2A extends free to the margin whereas in other Papilionoidea and most other Lepidoptera, it fuses with 1A after a short distance, and fails to reach the wing margin.  The mesothoracic aorta lacks a horizontal chamber (unlike the condition found in Hesperioidea, Hedyloidea, and other Papilionoidea) but has ostiae (Hessel 1966).  The laterocervicalia are joined ventromedially, a feature absent from other butterflies (Ehrlich 1958; Miller 1987)

Adult swallowtails fly in open areas (fields, vacant lots, meadows, open forest, sides of streams) near their food plants, especially where there are abundant flowers.

Caterpillars are found on their food plants.

Habitat Regions: temperate ; tropical ; terrestrial

Terrestrial Biomes: taiga ; chaparral ; forest ; rainforest ; scrub forest ; mountains

Wetlands: swamp

Swallowtail catepillars eat leaves and flowers of particular plans. One Michigan species only eats plants in the genus Aristolochia (Virginia Snakeroot, Dutchman's Pipe). Another prefers trembling aspen, another wild cherry. Several species eat plants in the carrot family.

Adult swallowtails sip nectar, but also mud and sometimes manure.

Many of these species defend themselves with toxic chemicals, or mimic species that do. The caterpillars all produce chemicals the repel ants. They also are camouflaged, especially when they are young. The eyespots may startle or confuse a predator.

Adult swallowtails are strong fliers, and hide in trees at night.

Known Predators:

• Aves
• Soricidae (eat pupae)
• Sigmodontinae (eat pupae)
• Anura (eat adults)
• Araneae, especially crab spiders and orb-weavers (eat adults)
• Formicidae (eat caterpillars)
• Hymenoptera (eat caterpillars and adults)
• mantids (eat adults)
• Diptera (eat caterpillars)
• Coccinellidae (eat eggs)
• Chrysopidae (eat eggs)
• Acari (eat eggs)

Like all butterflies, they mainly use scent and sight for communication. Males attract females with pheromones and special display flights. Females leave scent marks on plants where they've laid eggs, telling other female not to put their eggs there.

Adult behavior:

diurnal

Adult behavior:

From Scoble 1992: "In many species the adults are sexually dimorphic. Usually the female is mimetic, and may be polymorphic with each morph mimicking a different model."

Like all Moths and Butterflies, this family has complete metamorphosis. See More Information on Butterflies and Moths for an explanation of this. In cold climates they spend the winter as pupa in a chrysalis (no cocoon).

Development - Life Cycle: metamorphosis

These butterflies don't usually live more than a year. They often have two generations a year, with some adults emerging in the Spring, and then their offspring emerging as adults in Fall. This second generation only lives for a few months.

After mating, females lay eggs one at a time on the underside of leaves of their food plants.

Breeding season: Spring to Fall

Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; fertilization (Internal ); oviparous

There is no parental care in this family.

Parental Investment: no parental involvement

Larval food habits description:

Five families generally dominate the host records: Aristolochiaceae, Annonaceae, Lauraceae, Apiaceae, and Rutaceae.

Adult food habits description:

Feed at flowers while on the wing.

Systematic and taxonomic history:

Most authors accept three extant subfamilies: Baroniinae (containing just one species which occurs in Southwest Mexico); Parnassiinae (containing about 50 species, mostly in the Holarctic); and Papilioninae (containing 500+ species, mostly in old world tropics). Ehrlich (1958), Munroe (1961) and Hancock (1983) have discussed Papilionidae relationships.

Fossil record:

Durden and Rose (1978) propose a fourth subfamily of Papilionidae based on two species from middle Eocene deposits in Colorado, representing the extinct genus Praepapilio (Scoble, 1992).

View Papilionidae Tree

For several decades the favored view of Papilionidae has divided the family into four subfamilies: Baroniinae, Praepapilioninae, Parnassiinae, and Papilioninae (Munroe, 1961; Hancock, 1983), thought to be related (with constituent tribes) thusly:

Baroniinae and Praepapilioninae are both considered to be very primitive. The plesiomorphic nature of the sole species of the Baroniinae, Baronia brevicornis, has been supported by virtually all treatments. The sole genus of Praepapilioninae, Praepapilio, includes two species of extinct butterflies that were each described from single fossils found in a middle Eocene deposit in Colorado, U.S.A. (Durden and Rose, 1978). Praepapilio and Baronia share several striking similarities, but their exact relationship has been difficult to determine.

Both Praepapilio and Baronia have traditionally been considered to be the sister group to the rest of the swallowtails, but recently several alternative hypotheses regarding the root of the swallowtail tree have been considered. In an analysis of 103 morphological characters from 59 butterfly and 19 moth species, de Jong et al. (1996) presented some evidence that the genus Parnassius may be the sister group to the rest of the swallowtails. However, the intra-papilionid relationships in de Jong et al.'s (1996) study changed dramatically when the composition of the outgroups was altered, and a local analysis with a butterfly-only outgroup provided the traditional Baronia-as-sister rooting. Furthermore, de Jong et al. (1996) included only six papilionid species in the analysis, leaving out many taxa bearing characteristics key to understanding papilionid relationships.

Using a maximum-likelihood analysis of DNA sequence data, Caterino et al. (2001) found possible evidence for a root within the Papilioninae that would place Papilionini + Troidini as the sister group to the rest of the swallowtails. Because the likelihood of this intra-Papilioninae rooting was not found to be significantly higher than the traditional rooting, and because the traditional rooting is favored using maximum parsimony, we present the traditional rooting in our phylogeny.

Although a phylogenetic analysis of morphological characters has generally supported a monophyletic Parnassiinae (Miller, 1987), several other studies on morphological (Häuser, 1993; de Jong et al., 1996) and molecular (Yagi et al., 1999; Caterino et al., 2001) characters have called into question the monophyly of the subfamily. However, a new phylogenetic study on Parnassiinae, based on five mitochondrial and two nuclear genes, as well as 236 morphological characters (Nazari et al., 2007) has provided some evidence of a monophyletic Parnassiinae with three strongly supported tribes within the subfamily. This study also suggests that Praepapilio is sister only to Papilionini and Baronia is sister only to Parnassiinae, and likely none of the two are sister to all swallowtails as previously indicated.

With the exception of the intra-Papilioninae rooting alternative proposed by Caterino et al. (2001), the monophyly of the Papilioninae has been accepted by virtually every worker in the field. Despite this general consensus, the relationships of the tribes that comprise the subfamily have been debated. For our phylogeny, we follow the recommendation of Miller (1987) in recognizing Teinopalpini as the sister group to the Troidini + Papilionini group. At the time of this writing, no molecular data for Teinopalpini exist, and Miller (1987) provides the only rigorous phylogenetic analysis of the morphological data. The tribe Teinopalpini consists of only two species, both in the genus Teinopalpus. Munroe (1961) and Hancock (1983) did not grant Teinopalpini tribal status, but considered Teinopalpus to be a Graphiine genus (note that both authors used the name "Leptocircini" instead of "Graphiini").

Barcode of Life Data Systems (BOLD) Stats
                                        

Specimen Records:	3,651	Public Records:	1,941
Specimens with Sequences:	3,512	Public Species:	292
Specimens with Barcodes:	3,299	Public BINs:	231
Species:	488
Species With Barcodes:	453

Access Published & Released Data: Download FASTA File

Collection Sites: world map showing specimen collection locations for Papilionidae

One species in Michigan is considered threatened, it is the Pipe-vine Swallowtail, Battus philenor. It's existence is threatened in Michigan because its food plant has become rare. It is still common in other states. This species collects toxic chemicals from its food plant, and so birds won't eat it. Several other species are mimics of this species. If the toxic species disappears, the birds won't learn not to eat it, and the mimics won't get any protection from looking like it anymore.

These butterflies don't have strong effects on humans one way or the other. Sometimes they are a garden pest, eating carrots and related plants but this is not common. One species in the south is sometimes a minor pest of orange and lemon trees.