''Papilio rutulus'', the western tiger swallowtail, is a swallowtail butterfly belonging to the ''

Papilionidae Swallowtail butterflies are large, colorful butterflies in the family Papilionidae, and include over 550 species. Though the majority are tropical, members of the family inhabit every continent except Antarctica. The family includes the larg ...

'' family. The species was first described by

Hippolyte Lucas Pierre-Hippolyte Lucas (17 January 1814 – 5 July 1899) was a French entomologist. Lucas was an assistant- naturalist at the Muséum national d'Histoire naturelle. From 1839 to 1842 he studied fauna as part of the scientific commission on the e ...

in 1852. Like the other tiger swallowtails, the western tiger swallowtail was formerly classified in genus ''Pterourus'', but modern classifications all agree in placing them within ''

Papilio ''Papilio'' is a genus in the swallowtail butterfly family, Papilionidae, as well as the only representative of the tribe Papilionini. The word ''papilio'' is Latin for butterfly. It includes the common yellow swallowtail (''Papilio machaon''), ...

''.

Distribution

This common species is present in western North America. The normal range of the western tiger swallowtail covers much of western North America, from

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

North Dakota North Dakota () is a U.S. state in the Upper Midwest, named after the indigenous Dakota Sioux. North Dakota is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minnesota to the east, So ...

in the north to

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

and

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

in the south. Individuals occasionally turn up east of this range; in eastern North America, though, it is replaced by the similar eastern tiger swallowtail, ''

Papilio glaucus ''Papilio glaucus'', the eastern tiger swallowtail, is a species of butterfly native to eastern North America. It is one of the most familiar butterflies in the eastern United States, ranging north to southern Ontario, Canada, and is common in m ...

''.

Habitat

These butterflies are frequently seen in urban parks and gardens, as well as in rural woodlands and

riparian A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks a ...

areas.

Description

''Papilio rutulus'' can reach a

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan o ...

of . These large butterflies are brightly colored. The wings are yellow with black stripes and blue and orange spots near their tail. They have the "tails" on the hindwings that are often found in swallowtails. Young caterpillars resemble bird droppings, and as they molt, they eventually turn bright green, with a pair of large yellow eyespots with black and blue pupils. The chrysalis is green in summer and dark brown in winter, and looks like a piece of wood.

Biology

Butterflies emerge from winter chrysalids between February and May, the date depending on the temperature, so they are seen earlier in the more southerly and more coastal parts of their range. They are very active butterflies, rarely seen at rest. The adult females lay up to a hundred eggs in total. The eggs are deep green, shiny, and spherical. They are laid singly, on the undersides of leaves. The caterpillars emerge about four days later. They can feed on the leaves of a variety of trees, and the predominant food plant varies across their range; trees commonly used include cottonwood,

willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist so ...

quaking aspen ''Populus tremuloides'' is a deciduous tree native to cooler areas of North America, one of several species referred to by the common name aspen. It is commonly called quaking aspen, trembling aspen, American aspen, mountain or golden aspen, tr ...

, and many others. The caterpillars molt five times, eventually reaching a length up to 5 cm before pupating. In summer, the butterfly can emerge as quickly as 15 days after the caterpillar pupated, but when the caterpillar pupates in the fall, the butterfly does not emerge until the spring. The males often congregate, along with other species of swallowtail, at pools and along streams and rivers; they drink from the water and mud, extracting minerals, as well as moisture.

Gallery

File: Papilio rutulus- Western Tiger Swallowtail caterpillar.jpg , Caterpillar, pre-pupal state File: Papilio rutulus extending osmeterium 01.jpg, Caterpillar extending

osmeterium The osmeterium is a defensive organ found in all papilionid larvae, in all stages. The organ is situated in the prothoracic segment and can be everted when the larva feels threatened. The everted organ resembles a fleshy forked tongue (not unlik ...

File: Cherry blossoms Lake Balboa (20140330-0239).jpg, Adult of ''P. rutulus'' on ''

Prunus serrulata ''Prunus serrulata'' or Japanese cherry is a species of cherry tree that grows naturally in Japan, China, and Korea, and it also refers to a cultivar produced from ''Prunus speciosa'' (Oshima cherry), a cherry tree endemic in Japan.Toshio Katsu ...

'' File: Papilio rutulus.webm, Video clip

References