Geographic Range
The pearl crescent butterfly ranges from Alberta, Canada down south along the east
coast of the United States into Mexico. It has also been seen in Montana, Wyoming,
Colorado, New Mexico, Arizona, southeastern California, and Mexico. This species
is not found in the Pacific Northwest.
Habitat
The pearl crescent prefers open, moist, and sunny places. It is commonly found along
roadsides, fields and meadows, open pine forests, and vacant lots.
- Habitat Regions
- temperate
- Terrestrial Biomes
- savanna or grassland
- forest
- Other Habitat Features
- agricultural
Physical Description
Phyciodes tharos
is a small to medium sized butterfly that is 16-18 mm in length, with a wingspan
of 3-4 cm. There are characteristic traits that differentiate males from females.
Female wing coloration is generally darker than in males, with paler median spots.
Males have black antennal knobs, which females lack altogether. The butterfly's coloration
is black and vibrant orange, but the markings can vary geographically and can change
from season to season. Spring butterflies tend to be darker than summer generations
and have grey mottled hindwings. Typically, the upperside of the wings are brighter
orange with marks on the forewings. The underside of the hindwings are an unmarked
orange-brown to gray-brown, with a white cresent along the outer margin. Eggs are
green. Larvae are chocolate brown, have a white mid-dorsal line, and are covered
with tiny white dots. As larvae develop, caterpillars turn black and gain yellow
bands on thier sides and spots along their back. The caterpillar also has eight rows
of brown-yellow spines.
- Other Physical Features
- ectothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes colored or patterned differently
- sexes shaped differently
Development
As larvae develop, caterpillars turn black and gain yellow bands on thier sides and
spots along their back.
- Development - Life Cycle
- metamorphosis
Reproduction
During courtship, the male pursues the female butterfly while he is patroling the
host plant. If the female is flying, she lands, keeping her wings spread. Next,
the male lands behind her, possibly displaying his wings and on occasion fluttering
them. With his wings partially opened he crawls under her hindwings to mate. For
highly receptive females, which are usually motionless, the male rarely displays or
flutters before mating. On the other hand, an unreceptive female will close her wings,
possibly causing the male to leave. If the male doesn't fly away, the female may
raise her abdomen (so he cannot join), turn and crawl away, drop down into vegetation,
or fly away to escape.
Females lay eggs in masses of 20-200 (average 36), sometimes two or three layers deep on the underside leaves of a host plant (usually aster leaves).
- Key Reproductive Features
- semelparous
- sexual
- fertilization
- oviparous
After oviposition, there is no further parental involvement.
- Parental Investment
-
pre-fertilization
- provisioning
-
protecting
- female
Behavior
The pearl crescent will descend onto leaves, stones, flowers,or bare ground. In the
field,
Phyciodes tharos
can be identified by the way it holds it wings out to the side and "saws them up
and down" during its descent (Klots and Klots 1951). This species also keeps its
wings spread at rest, basking in the sun, or feeding. Like most brushfooted butterflies,
the pearl cresent is a puddle visitor, and males will behave territorially toward
other males approaching the same puddle -especially around the puddles where females
tend to group. They have been recorded darting after other butterflies that come
near its perch or puddle and driving them out of the area. Various theories speculate
the cause of activity is to drive out competing males from claiming territory or mating
with females as they pass through quickly. This is studied as an evolutionary adaptation
that offers increased chance of success in search for a partner and ensures that the
offspring receive food and protection. The Pearl Crescent has been seen chasing more
than just other males of their species. Due to their investigative and aggressive
behavior, they have been observed flying out at passing objects, including butterflies
of different species, insects, birds and frisbees. They will even leave their path
of flight to observe human activities.
Phyciodes tharos
has different flight patterns depending on region. In warmer climates such as Texas
and Florida there are several flights throughout the year, whereas in northern regions
there are few flights, and only from May to September. From April to November there
are several broods in the north. In the south (Florida, Texas, New Mexico, and Mexico)
there are three to four broods throughout the year.
- Key Behaviors
- flies
- diurnal
- territorial
Food Habits
The adult uses a siphoning technique to feed on nectar from an array of flowers including
dogbane, swamp milkweed, shepherd's needle, asters, black-eyed susans, thistle, gloriosa
daisies, white clover, and winter cress. The butterfly siphons nectar out of the
flower by using its coiled tongue (proboscis). Caterpillars have chewing mouthparts
used to eat leaves and other materials off of plants.
- Primary Diet
- herbivore
- Plant Foods
- leaves
- nectar
- flowers
Economic Importance for Humans: Positive
Economic Importance for Humans: Negative
This butterfly has little economic significance, although larvae can be a nuisance,
eating the leaves off of their host plants.
Conservation Status
The pearl crescent butterfly is in no danger of extinction, although it may be rare in parts of its range, especially at the periphery.
Other Comments
The pearl crescent is one the most common of 700 species of butterflies in the United
States and Canada. Many subspecies of
Phyciodes tharos
have been identified.
Phyciodes tharos arctica
, found in Newfoundland, has a deeper more orange and yellow underside.
Phyciodes tharos tharos
, a subspecies found in New York, is lighter than the subspecies found in Newfoundland.
Other subspecies found in Colorado and Washington are
Phyciodes tharos morpheus
and << Phyciodes campestris>>. Similar species to
P. tharos
are the Silvery Checkerspot and Phaon Crescent.
Additional Links
Contributors
Sara Diamond (author), Animal Diversity Web.
Jamie King (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- agricultural
-
living in landscapes dominated by human agriculture.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- heterothermic
-
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- metamorphosis
-
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
- semelparous
-
offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- internal fertilization
-
fertilization takes place within the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- diurnal
-
- active during the day, 2. lasting for one day.
- territorial
-
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- herbivore
-
An animal that eats mainly plants or parts of plants.
- folivore
-
an animal that mainly eats leaves.
- nectarivore
-
an animal that mainly eats nectar from flowers
References
Carter, D. 1992. Eyewitness Handbook of Butterflies and Moths . New York: Dorling Kindersley, Inc.
Klots, A. 1951. Field Guide to Butterflies of North America, East of the Great Plains . Boston: Houghton Mifflin Co..
Pyle, R. 1984. Audubon Society for Butterfly Watchers . New York: Charles Scribner's Sons.
Schneck, M. 1990. Butterflies . Pennsylvania: Rodale Press.
Scott, J. 1986. The Butterflies of North America . Standford, California: Stanford University Press.
Taylor, J. 1994. Some Common Butterflies. Conservationist , March-June, 1994: 48, 5-6, 10-13.