Papilio eurymedon
Encyclopedia
Papilio eurymedon, the pale swallowtail or pallid swallowtail is a relatively common swallowtail butterfly
found throughout much of the western United States. It is found on the Pacific coast from northern Baja California
to southernmost British Columbia
and inland to New Mexico
and the Black Hills
of South Dakota
. It is present from the coast to western Montana
and Wyoming
to northern New Mexico
. It is absent from most of Nevada
and western Utah
. It prefers open woodlands and forest clearings, especially near permanent bodies of water such as ponds, but also urban parks and occasionally is seen in suburban areas. Though not as common as the Western Tiger Swallowtail, the pale swallowtail can be seen in large numbers at puddling parties
where up to a dozen or more males may be seen gathered. There they join other species to sip water from damp soil to obtain nutrients for mating. Their appearance is quite similar to that of the western tiger swallowtail except they are a white-cream color or very pale yellow. Some pale swallowtails also have differing amounts of red-orange patches on the wings just above the tail as well as on the . Tiger stripes and borders are thicker than those of western tiger swallowtails. The wingspan is typically 3.5 to 4.5 inches.
The pale swallowtail has a single brood
throughout most of its range, but two or more along the Pacific Coast. Adults fly from April to October and are most common in May and July. Caterpillar
s enter their pupa
stage in the fall and overwinter before emerging as adults. Eggs are laid singly on plant hosts which include members of the Ceanothus
family, including buckbrush
, mountain balm, and mountain lilac, as well as red alder, ccean spray
, bitter cherry, and Serviceberry species. Caterpillars are plump green with a single yellow band behind the thorax
. They have two eye-shaped spots
on the upper thorax which may help frighten predators. Like most swallowtails they have red wishbone shaped organ called the osmeterium
which pops out from behind the head and releases a foul odor to warn off predators. Caterpillars turn brown just before the fifth moult
. The pupa is brown and looks like a piece of bark. As they pupate they face upright, secure the tip of the abdomen to a branch with a silk
thread, and hang freely.
Swallowtail butterfly
Swallowtail butterflies are large, colorful butterflies that form the family Papilionidae. There are over 550 species, and though the majority are tropical, members of the family are found on all continents except Antarctica...
found throughout much of the western United States. It is found on the Pacific coast from northern Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
to southernmost British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
and inland to New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
and the Black Hills
Black Hills
The Black Hills are a small, isolated mountain range rising from the Great Plains of North America in western South Dakota and extending into Wyoming, USA. Set off from the main body of the Rocky Mountains, the region is something of a geological anomaly—accurately described as an "island of...
of South Dakota
South Dakota
South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of and an estimated population of just over...
. It is present from the coast to western Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
and Wyoming
Wyoming
Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
to northern New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...
. It is absent from most of Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
and western Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
. It prefers open woodlands and forest clearings, especially near permanent bodies of water such as ponds, but also urban parks and occasionally is seen in suburban areas. Though not as common as the Western Tiger Swallowtail, the pale swallowtail can be seen in large numbers at puddling parties
Mud-puddling
Mud-puddling is the phenomenon mostly seen in butterflies and involves their aggregation on substrates like wet soil, dung and carrion to obtain nutrients such as salts and amino acids. This behaviour has also been seen in some other insects, notably the leafhoppers.Lepidoptera are diverse in...
where up to a dozen or more males may be seen gathered. There they join other species to sip water from damp soil to obtain nutrients for mating. Their appearance is quite similar to that of the western tiger swallowtail except they are a white-cream color or very pale yellow. Some pale swallowtails also have differing amounts of red-orange patches on the wings just above the tail as well as on the . Tiger stripes and borders are thicker than those of western tiger swallowtails. The wingspan is typically 3.5 to 4.5 inches.
The pale swallowtail has a single brood
Offspring
In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...
throughout most of its range, but two or more along the Pacific Coast. Adults fly from April to October and are most common in May and July. Caterpillar
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
s enter their pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
stage in the fall and overwinter before emerging as adults. Eggs are laid singly on plant hosts which include members of the Ceanothus
Ceanothus
Ceanothus L. is a genus of about 50–60 species of shrubs or small trees in the buckthorn family Rhamnaceae. The genus is confined to North America, the center of its distribution in California, with some species in the eastern United States and southeast Canada, and others extending as far south...
family, including buckbrush
Buckbrush
Buckbrush is the common name for several species of North American shrubs that deer feed on, including but probably not limited to:*Andrachne phyllanthoides, maidenbrush * Some western North American species of the genus Ceanothus...
, mountain balm, and mountain lilac, as well as red alder, ccean spray
Holodiscus discolor
Holodiscus discolor, commonly known as ocean spray, creambush or ironwood, is a shrub of western North America. It is common in the Pacific Northwest where it is found in both openings and the forest understory at low to moderate elevations.-Description:Holodiscus discolor is a fast-growing...
, bitter cherry, and Serviceberry species. Caterpillars are plump green with a single yellow band behind the thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...
. They have two eye-shaped spots
Eyespot (mimicry)
An eyespot is an eye-like marking. They are found on butterflies, reptiles, birds and fish. In members of the Felidae family , the white circular markings on the backs of the ears are termed ocelli, and they are functionally similar to eyespots in other animals.Eyespots may be a form of...
on the upper thorax which may help frighten predators. Like most swallowtails they have red wishbone shaped organ called the osmeterium
Osmeterium
The osmeterium is a fleshy organ found in the prothoracic segment of larvae of Swallowtail butterflies including Birdwings. This organ emits smelly compounds believed to be pheromones. Normally hidden, this forked structure can be everted when the caterpillar is threatened, and used to emit a...
which pops out from behind the head and releases a foul odor to warn off predators. Caterpillars turn brown just before the fifth moult
Moult
In biology, moulting or molting , also known as sloughing, shedding, or for some species, ecdysis, is the manner in which an animal routinely casts off a part of its body , either at specific times of year, or at specific points in its life cycle.Moulting can involve the epidermis , pelage...
. The pupa is brown and looks like a piece of bark. As they pupate they face upright, secure the tip of the abdomen to a branch with a silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...
thread, and hang freely.