by Steven J. Cary
Swallowtails (Papilionidae). Swallowtails are our largest, most recognizable, and best studied butterflies. Our 14 swallowtail species include familiar, widespread, tailed beauties like the Western Tiger, the rarely-seen Indra, and an ancient, tundra-dwelling Parnassian. Some are very infrequent, yet spectacular, strays like Polydamas, Ornythion, Broad-banded, and Palamedes. Photos for some of our species are needed, especially the subtropical strays. If you can fill a gap, we will be delighted to credit you for your image.
- Rocky Mountain Parnassian (Parnassius smintheus)
- Pipevine Swallowtail (Battus philenor)
- Polydamas Swallowtail (Battus polydamas)
- Indra Swallowtail (Papilio indra)
- Old World Swallowtail (Papilio machaon)
- Black Swallowtail (Papilio polyxenes)
- Anise Swallowtail (Papilio zelicaon)
- Broad-banded Swallowtail (Heraclides pallas)
- Ornythion Swallowtail (Heraclides ornythion)
- Giant Swallowtail (Heraclides cresphontes)
- Palamedes Swallowtail (Pterourus palamedes)
- Two-tailed Swallowtail (Pterourus multicaudata)
- Western Tiger Swallowtail (Pterourus rutulus)
- Pale Swallowtail (Pterourus eurymedon)
Parnassians (Papilionidae: Parnassiinae). Parnassians are tail-less tundra-dwellers that look more like large Pierids than swallowtails. Mating is concluded when males secrete a waxy plug onto the lower abdomen of females to prevent subsequent fertilization by other males. This ‘sphragis’ is evolutionarily primitive and is unique to Parnassians.
Parnassius smintheus E. Doubleday Smintheus Parnassian
Description. Smintheus is white dorsally and ventrally; the forewing apex is translucent. All wings have black patches and red spots. Wingspan is about 2 inches. Range and Habitat. Parnassius smintheus is a high-latitude, high-altitude insect in the North America Cordillera from the southwestern Yukon to north-central New Mexico (counties: Co,Mo,RA,SM,SF,Ta). Here it is restricted to treeline Hudsonian Zone habitats in the Sangre de Cristo Mountains, usually in open areas between 10,000′ and 12,500′ elevation. Slopes above the Santa Fe Ski Area represent its southernmost occurrence. Life History. Smintheus larvae eat only Crassulaceae (stonecrops); Sedum lanceolatum is the likely host here. Eggs or young larvae overwinter. Panassius smintheus is usually univoltine, but it may be biennial (one generation every two years) at extreme high altitudes. Flight. New Mexico records span the period June 2 to August 27, but July is the best time to find them; there is one ultra-late record for September 27. Adults gather nectar from alpine flowers. Males patrol patiently across treeless tundra in search of females. Comments. Smintheus Parnassian is our only representative of this ancient group of swallowtails. Our populations are assigned to southern Rocky Mountain subspecies Parnassius smintheus sayii W. H. Edwards. Until the recent revision by Shepard and Manley (1998), Rocky Mountain populations were placed with the Holarctic Parnassius phoebus (Fabricius) complex.
True Swallowtails (Papilionidae: Papilioninae). With wingspans of 3 to 6 inches, our 13 species of true swallowtails are large, colorful, confident flyers. The name “swallowtail” comes from a resemblance of these butterflies’ hindwings to the forked tails of avian swallows. Because they have been popular subjects of professional and amateur study, the life cycles, hostplants, and behaviors of our species are reasonably well known.
Battus philenor (Linnaeus) Pipevine Swallowtail (updated March 23, 2021)
Description. This large species is black, but the hindwing above has iridescent blue-green scaling and a submarginal row of creamy spots. Below, the glossy, steel-blue hindwing has a row of yellow-orange spots. Range and Habitat. Pipevine Swallowtails breed year-round in Mexico, southern Arizona, and much of the southeast US. Larvae have been found in southwest New Mexico (counties: DA,Hi,Lu) in April, May and August, so it breeds there as well. Adults wander widely, accounting for all the records in central and northern New Mexico (all counties except RA,Sv,SJ,Va), where there are no native hosts on which to place eggs. Life History. Larvae feed only on plants in the Pipevine Family (Aristolochiaceae). Aristolochia watsoni, a vine of desert arroyos, is used in southwest New Mexico. Plants in this family contain chemicals that render larvae and adults of Battus philenor bad-tasting. Larvae are black to bright orange-red, advertising their unpalatability. Flight. In southern deserts adults are in flight by spring; two or more additional broods are hatched before winter cold. Our records fall between February 15 and November 11. Numbers peak in April, then rise again to peak from June to August when strays to northern New Mexico are most frequent. Both sexes are fond of nectar, where adults beat their wings rapidly while siphoning. Males are casual hilltoppers, where their likeness to female Papilio polyxenes confuses males of the latter. Comments. Battus philenor is the distasteful model in a mimicry ring that includes Limenitis arthemis astyanax and female Papilio polyxenes.
Battus polydamas (Linnaeus) Polydamas Swallowtail
Closely related to the previous species, Battus polydamas has distinct differences. It lacks tails and iridescent blues; there is a yellow submarginal band on both forewing and hindwing. This species is Neotropical, ranging south to Argentina and north to the southern US. It breeds as far north as south Florida and south Texas, but it is only a rare stray in the interior US. As is true of all other Battus species, Polydamas larvae eat plants in the Aristolochiaceae, but there is no evidence of breeding in the southwest US. It is a strong flyer and adults come to nectar. Our only record is from Mahoney Wash, Florida Mountains (Luna County), on 12 May 1985 (S. Cary).
Papilio (Papilio) indra Reakirt Indra Swallowtail (updated March 21, 2021)
Description. Indra is one of four similar “black” swallowtails. Indra differs by having a black abdomen with a single yellow side patch near the posterior end; no yellow dots are visible from above. The postmedian yellow band on the dorsal hindwing is reduced to a narrow strip. The submarginal blue band is well developed. Tails are short or stubby, though not so much in our subspecies. Range and Habitat. This western butterfly occurs from southwest British Columbia to northern Baja California and east to the Four Corners and South Dakota. It is an Upper Sonoran Zone insect. Certain geographic races of this butterfly are restricted to some of the most starkly beautiful, least accessible lands in the Southwest. It appears to be of very limited extent in New Mexico (counties: MK?,Sv?,SJ). Life History. In Colorado, Indra Swallowtails use several larval hosts in the Apiaceae; most are strongly scented desert shrubs including Cymopterus purpurea, Aletes acaulis, Harbouria trachypleura and various species in the genera Lomatium, Pteryxia and Tauschia. Pupae are drought-tolerant and able to diapause for more than one year when necessary. Flight. We have two documented observations from May 27 and July 16. Most observations from elsewhere are clustered in May. Inconveniently for humans, males patrol the rockiest ridges and highest clifftops within the general habitat, though guides suggest they may perch on the ground below summits. Comment 1. With so few sightings, the status of Indra Swallowtail in New Mexico is unclear. Only two records are credible. One old record (MK) is credible, but the location of its capture cannot be assumed. Though sent east from “Fort Wingate” c. 1917, John Woodgate used that locality name for material he collected within a considerable radius of the old fort itself. The second confirmable record is a specimen at the Utah Natural History Museum taken in 1961 by H. Hall at Navajo Dam (SJ). Since then, intensive surveys of the Chuska and Zuni Mountains by Holland (1984) failed to turn it up. Other reports would benefit from confirmation. Comment 2. Our populations are subspecies Papilio indra minori Cross, which occurs more reliably in western Colorado.
Papilio (Papilio) machaon Linnaeus Old World Swallowtail (updated January 22, 2021)
Description. Old World Swallowtail has the same yellow marginal and postmedian spot bands sported by Black Swallowtails. You can tell them apart in several ways: dorsal postmedian yellow spots are somewhat diffuse, not sharp-edged; the ventral hindwing postmedian band is pale yellow, not suffused with orange; the red eyespot near the hindwing tail has a flattened, black pupil touching the inner wing margin; and tegulae are yellow. The abdomen is marked like that of Papilio polyxenes. Papilio machaon also occurs in form brucei W. H. Edwards, in which yellow areas are expanded to resemble Papilio zelicaon form gothica. Range and Habitat. In North America, Old World Swallowtail is a Great Basin insect that is distributed from California to New Mexico and north to Canada. It flies in Transition Zone savannas of New Mexico’s northwest quadrant (counties: Be,Ca,Ci,Gr?,LA,MK,RA,Sv,SJ,SF,So,Ta,To), 6400 to 9200’. Black forms dominate in New Mexico; yellow form brucei prevails farther north, but sometimes turns up here. Life History. Larvae eat only Artemisia dracunculus (green sage or wild tarragon; Asteraceae). A mature larva was seen feeding on this plant at Valle Canyon (LA) on 27 June 1998 (S. Cary, D. Hoard). This sage lacks the essential oils and pungent aroma of other sages. Pupae overwinter. Flight. Old World Swallowtails are bivoltine here, with peak numbers in May and July. Actual records span April 25 to September 1. Males patrol hilltops, sometimes jostling with Black and Anise Swallowtails. Adults come to nectar and moist earth. Comments. New World populations like ours are assigned to subspecies Papilio machaon bairdii W. H. Edwards. Some texts elevate those populations to species status and refer to this bug as Baird’s Swallowtail or Western Black Swallowtail. Close resemblance of Old World and Black Swallowtails has caused identification problems. Specimens of alleged Papilio machaon from some parts of New Mexico (counties: Li,Ot,Si,So) were examined by Richard Holland and found to be Papilio polyxenes. Another report (Gr) was considered uncertain by the collector himself (Ferris 1974). Resolution of those uncertainties clarified that Papilio machaon in New Mexico is limited to our northwest quadrant. It has not been found east of the Jemez, Sandia or Manzano Mountains, nor south of the Zuni Mountains. It flies in Bluewater Canyon below Bluewater Dam in Bluewater Lake State Park.
Papilio (Papilio) polyxenes Fabricius Black Swallowtail (updated March 23, 2021)
Description. Papilio polyxenes males are black with postmedian and marginal rows of yellow spots above and below, on forewing and hindwing. Between these two rows on the hindwing are blue spots. The ventral hindwing’s postmedian yellow row is suffused with orange. The hindwing tornus has an orange eye-spot with a black pupil that is round and centered. The black abdomen has four to six rows of yellow dots; tegulae are black. Females mimic Battus philenor with heavy blue scaling in place of the postmedian yellow band on the hindwing above. Range and Habitat. Black Swallowtail is resident east of a line that runs from Guaymas, Mexico, through the Four Corners (where Utah, Colorado, Arizona and New Mexico come together) to Saskatchewan. Its range includes all of New Mexico, where it lives in a variety of habitats as different as deserts, grasslands, cities and piñon-juniper woodlands, 3300 to 9000′ elevation. Life History. Females place their eggs on many different species of umbellifers (Apiaceae, or Carrot Family), including culinary herbs like anise, fennel and dill. Native hosts include water hemlock (Cicuta douglasii), poison hemlock (Conium maculatum), mountain parsley (Pseudocymopteris montanus) and cutleaf water parsnip (Berula erecta). Flight. Black Swallowtails complete three generations per year in southern New Mexico with peak numbers in April, July and September; extreme dates are March 5 and October 9. Northern New Mexico has two overlapping generations from May to September, peaking in June and July. Adults seek nectar. Males are strong hilltoppers, sometimes climbing above 12,000 feet. Comments. Occasional spring individuals in southern New Mexico (Ed,Hi,Va) resemble the yellow southwestern subspecies Papilio polyxenes coloro W. G. Wright. Otherwise, expect the widespread eastern version, Papilio polyxenes asterius Stoll. Females frequent urban herb gardens with dill and fennel.
Papilio (Papilio) zelicaon Lucas Anise Swallowtail (updated December 28, 2020)
Description. Anise Swallowtail has black [form nitra (W. H. Edwards)] and yellow [form gothica (Remington)] versions. The latter version dominates in New Mexico and is arguably our most beautiful swallowtail. The postmedian yellow band is widened to the hindwing base. The black abdomen lacks the yellow racing stripes of Papilio machaon brucei, with which it is easily confused. Form nitra looks like Papilio polyxenes, but the abdomen has only one row of yellow dots on each side, instead of two or three. In both color forms of Anise, the hindwing red eyespot has a black pupil that is centered and round, like Papilio polyxenes. Range and Habitat. Anise Swallowtails live from Baja California to British Columbia, east to Saskatchewan and New Mexico. Here it lives in Canadian Zone coniferous woodlands and savannas in our northwest quadrant. Unlike Old World Swallowtails, Anise is distributed farther east to the eastern foothills of the Sangre de Cristos (counties: Be,Ci,Co,LA,MK,Mo,RA,Sv,SJ,SF,SM,Ta,To,Un). Form nitra is less widespread (counties: Be,LA,MK,RA). The altitudinal range of Anise Swallowtails here is 6000 to 12,800′; the higher reports are hilltopping males. Life History. Like Papilio polyxenes, Papilio zelicaon larvae will eat many Apiaceae. Oviposition is reported on Harbouria trachypleura and Conium maculatum (poison hemlock) in Colorado. Pupae overwinter. Flight. Anise Swallowtails have one extended annual generation in New Mexico. Adults fly from April 12 to August 17, but primarily May and June. Males aggressively patrol hilltops, which can be the most reliable places to find this swallowtail. Comments. In the semi-arid Southwest, many desert umbellifers have evolved oily compounds to reduce transpiration of precious water. Often each plant species has its own unique oils, with distinctive scents. These oils have become crucial links between butterfly herbivores and their host plants. Female swallowtails distinguish plants by their scents, thus identifying proper plants for oviposition.
Heraclides pallas (G. Gray) Broad-Banded Swallowtail (updated March 9, 2021)
Though seen here but rarely, Broad-Banded Swallowtails resemble Giants and Ornythions (see below). On males, dorsal forewing submarginal yellow spots hug the wing margin. The dorsal forewing also has a yellow spot in the discal cell, but there is no yellow on the tails. Much darker, females lack the broad yellow bands and have one or no tails. Heraclides pallas is multi-brooded in the Neotropics, breeding from Argentina to south Texas. Adults occasionally stray farther north and reports are known from southern Arizona and New Mexico. Larvae eat plants in the citrus family (Rutaceae), but reproduction is not expected in New Mexico. This butterfly was first recognized in New Mexico by Christopher Rustay, who videotaped a relatively fresh male nectaring in a patch of roadside alfalfa near Roy (Harding County) on 22 June 2003. His find prompted a review of specimens of ostensible Ornythion collected by the author in the Guadalupe Mountains of Eddy County in 1986. One ragged female proved to be Heraclides pallas; that specimen, taken in Bullis Canyon (Chaves County) on 28 July 1986, is in the Richard Holland collection, now in the C. P. Gillette Museum at Colorado State University. Until the publication of Pelham (2019), this butterfly was previously called Papilio astyalus Godart.
Heraclides ornythion Boisduval Ornythion Swallowtail
This beauty may be confused with Giant and Broad-banded Swallowtails. The postbasal band of dorsal hindwing yellow spots is narrower than on Broad-banded and broader than on Giants. Females have tails and may look like males, with yellow postbasal bands narrower and paler, or with dorsal yellow bands heavily suffused with brown. On the forewing above, the submarginal series of small yellow lunules remains separate from, and parallel to, the postmedian band of larger yellow spots. Ornythion breeds in the eastern tropics of Mexico, rarely entering southern New Mexico as a stray. Like Giants, Ornythion larvae eat plants in the citrus family (Rutaceae); there is no evidence of reproduction here, but Choisya dumosa and Ptelea trifoliata are potential warm season hosts. Only three New Mexico records are known; all fall between July 26 and August 27. It was first found by William A. Baltosser at the Las Cruces (DA) dump, 27 August 1975. A female taken at Rattlesnake Springs (Ed) on 26 July 1986 is in the Richard Holland collection, now in the C. P. Gillette Museum at Colorado State University.
Heraclides cresphontes Cramer Giant Swallowtail
Description. Giant is large even for a swallowtail. On the upperside, warm yellow spot bands crisscross on a dark brown background. Each hindwing has a long tail with a yellow spot. Range and Habitat. Giant Swallowtails live and breed in Tropical and Subtropical Life Zones in the southeast US and as well as east and west coasts of Mexico, south to Colombia. In good years, adults wander north into New Mexico. Giants reproduce seasonally along our southern border, producing fresh individuals late in the season, but none of its life stages survive our cold winters, even in relatively mild southern New Mexico, though that may be changing. It is almost routine in southern New Mexico and at low elevations (counties: Ch,DB,Ed,Gr,Hi,Li,Lu,Ot,Ro,So,To). There are a small number of sightings from northern New Mexico and at higher elevations (counties: Ca,Be,Co,Sv). Life History. Larvae eat plants in the citrus family (Rutaceae). Seasonal reproduction occurs on our two native Rutaceae: Choisya dumosa and hoptree or wafer ash (Ptelea trifoliata). Farther south, larvae are pests of citrus orchards, giving rise to its other common name, Orange Dog. Flight. Giant Swallowtails breed all year long farther south, appearing as occasional summer strays in New Mexico. Our records fall between April 21 and September 28, mostly July to September. Adults love thistle nectar. Comments. Some authors treat Heraclides as a subgenus within the genus Papilio. This present work follows Pelham (2019).
Pterourus palamedes Drury Palamedes Swallowtail
This large butterfly is dark brown with a pattern of yellow spots generally reminiscent of an inflated Black Swallowtail. The hindwing is larger, more distended and more rounded than in Papilio polyxenes. The pattern of yellow, red and blue markings on the hindwing beneath is unlike any other North American swallowtail. Palamedes is a very rare stray that has been recorded only once in New Mexico, so do not go looking for it here. It is resident and breeds most of the warm season in subtropical southeast US along the Gulf of Mexico coast. Larvae eat various Lauraceae such as Sassafras sp. Our one record is from Raton (Co) in late June 1935, by J. R. Merritt. Although capable of wandering long distances, it rarely wanders upwind against the prevailing westerlies all the way to the foothills of the Sangre de Cristo Mountains. Some authors treat Pterourus as a subgenus within the genus Papilio. This present work follows Pelham (2019).
Pterourus multicaudata W. F. Kirby Two-Tailed Swallowtail (updated July 22, 2021)
Description. Pterourus multicaudata has a warmer yellow ground color with long, narrower black stripes and a brighter appearance than the similar Pterourus rutulus. Each hindwing has one long and one short tail. With a wingspan that can approach 6 inches for females, this is our largest butterfly. Range and Habitat. Two-Tailed Swallowtails live throughout western North America and south as far as Central America. In New Mexico they inhabit Upper Sonoran Zone riparian canyons. They usually are found below 7500′, but often wander up valleys to higher elevations. It is most common in southern New Mexico, but is regular in much of the state (counties: all but Cu,Le). Life History. Several deciduous trees and shrubs are larval hosts. Hoptree (Ptelea trifoliata, Rutaceae) is an important host in southern and central New Mexico. Chokecherry (Prunus virginiana, Rosaceae) is used in northern New Mexico. Various species of ash are used statewide, especially velvet ash (Fraxinus velutina, Oleaceae), which is often sold by nurseries as ‘Arizona Ash.’ City gardens attract this butterfly and urban plantings of native ash allow it to reproduce. Pupae overwinter. Flight. Adult Two-Tails begin to emerge with persistent warm weather in spring. There are two to three annual generations in southern New Mexico, with indistinct flight peaks from April through August. There are two broods in northern New Mexico, with peak numbers in July. Extreme flight dates are (January 29) March 22 and October 20. Two-Tailed Tigers patrol majestically along canyons, nectar at thistles and red flowers, and sip from wet sand. Comments. New Mexico has the nominate subspecies. A larva rescued from an asphalt parking lot in Santa Fe pupated on July 27, 1997; after wintering in an unheated garage, the adult emerged exactly 365 days later, on July 27, 1998.
Pterourus rutulus Lucas Western Tiger Swallowtail
Description. Western Tiger is one of three New Mexico swallowtails with black ‘tiger’ stripes. Compared to Two-Tailed Swallowtails, Pterourus rutulus is smaller and lemony yellow with relatively broad, short, black stripes. Each hindwing has one full tail. Pale Swallowtail is white rather than yellow Range and Habitat. Western Tigers inhabit riparian settings in mountains of the western US, chiefly in Transition and Canadian Zone environments. They occupy New Mexico’s higher mountains (counties: Be,Ca,Ci,Co,Gr,Ha,Hi,Li,LA,MK,Mo,Ot,RA,Sv,SJ,SM,SF,Si,So,Ta,To,Un), usually between 7000 and 10,000′ altitude. Life History. Larvae eat foliage of several deciduous shrubs and trees in several plant families. Among these are aspen (Populus) and willow (Salix) [both Salicaceae]; ash (Fraxinus, Oleaceae), wild cherry (Prunus, Rosaceae) and alder (Alnus, Betulaceae]. Urban plantings of shade-offering native ash trees (e.g., Fraxinus velutina) help this colorful species reproduce in urban and suburban settings such as Santa Fe and Albuquerque. Flight. Western Tigers complete one generation per year. Adults fly in early summer and are usually most abundant in June. Early and late dates in New Mexico are May 12 and September 2. Adults patrol up and down mountain stream corridors looking for mates and shopping for nectar. They sometimes gather at moist earth. Comments. Western Tiger is related to the Eastern Tiger, Pterourus glaucus (Linnaeus), with which it hybridizes in the northern Great Plains. Some experts lump them as one species. Others consider them separate and further divide southwestern populations into nominate Pterourus rutulus rutulus (most of New Mexico) and subspecies Pteourus rutulus arizonensis W. H. Edwards (counties: Ca,Gr,Hi,So,Si). The latter race has broad dark margins, but this difference is minor.
Pterourus eurymedon Lucas Pale Swallowtail
Description. Pale Tiger is about the same size as the Western Tiger, but it is creamy white rather than yellow. In addition, black stripes and black submarginal areas are broader, giving it a darker look. Each hindwing has a tail. Range and Habitat. This swallowtail occurs north through the Rocky Mountains to British Columbia, then south along the Sierra Nevada to Baja California. It has a more limited distribution in New Mexico than other Tigers (counties: LA,MK,Mo,RA,Sv,SM,SF), 7000 to 10,600’. It is restricted to Transition and Canadian Zone meadows in our north-central mountains; it seems uncommon east of the Rio Grande. Life History. Fendler’s Buckthorn (Ceanothus fendleri; Rhamnaceae) is the host. Wild cherries (Prunus spp., Rosaceae) may suffice in a pinch. Chrysalids overwinter. Flight. Pale Tigers are on the wing from May 25 to July 24, mostly in June. Adults patrol through mountain meadows, stopping occasionally to sip nectar or moisture, but they are rarely seen in large numbers. Comments. The Los Angeles (California) County Museum curates our oldest specimen, collected in near Ft. Wingate (MK) by John Woodgate on 3 June 1912. A recent survey of the Zuni Mountains (Holland 1984) failed to produce Pterourus eurymedon, casting some doubt on the origin of Woodgate’s specimen.