Phidippus audax

Geographic Range

Bold jumping spiders, Phidippus audax, occur across North America from southeastern Canada west to British Columbia, and south to Florida, the Gulf Coast and northern Mexico. The species may have been absent from the arid southwest prior to modern settlement and irrigation, but have been introduced there by human activity. The species also occurs on the island of Cuba, and has been introduced to the Hawaiian Islands as well. (Barnes, 2004; Huntley, 1997; Jackman, 1997; Suman, 1964; Vest, 1999)

Habitat

The natural habitats of bold jumping spiders are are grasslands, prairies, and open woodlands. They also occur in agricultural habitat, especially old fields, and are frequently found in backyards and gardens. (Barnes, 2004; Jackman, 1997; Vest, 1999)

Physical Description

The most distinctive features on P. audax are the eight eyes. The forward-facing anterior median (AM) eyes are the largest of all the eyes. When a person looks at the spider, the AM eyes are the ones that look back at that person. To the side of the AM eyes are the smaller anterior lateral (AL) eyes. Behind the AL eyes, and almost on top of the head, are the posterior median (PM) eyes and posterior lateral (PL) eyes. Jumping spiders have very keen eyesight. Eyesight is essential for hunting and courting.

Females measure from 8 to 15 mm in length, and males are between 6 and 13 mm.

These spiders are hairy; cephalothorax and abdomen are black with little, white hairs. The cephalothorax is high, heavy, and convex. The abdomen is distinctly marked. In the middle of the abdomen, there is a large, triangular white spot, with two smaller spots posterior and lateral to the large spotk. The large spot may be orange in juveniles, and there is some variation in spot patterns within the species, though spots are always white, yellow, or orange. In some individuals there are two oblique lateral stripes. The chelicerae are iridescent green. Males are smaller than females, with more starkly contrasting markings, and more iridescence on the chelicerae.

The powerful hind legs are responsible for propelling the spider into a leap.

This species is venomous, but the bite is not dangerous to humans. (Barnes, 2004; Comstock, 1980; Huntley, 1997; Jackman, 1997; Kaston, 1978)

  • Sexual Dimorphism
  • female larger
  • Range length
    6 to 15 mm
    0.24 to 0.59 in

Reproduction

The process of copulation begins with a male courting a female. There is a species-specific courting display, which includes movement of the forelegs, palps and chelicerae. The male lifts certain legs and shows off his colored spots. If the female approaches too rapidly, the male will jump away. (Comstock, 1980; Knopf, 1980; Preston-Mafham and Preston-Mafham, 1996)

In males, a pair of coiled testes lie in the anterior part of the abdomen. As with nearly all spiders, there is no copulatory organ, and the seminal fluid is transferred to a female by a highly specialized appendage of the palpus during copulation. Females possess ovaries, oviducts, a uterus, a vagina, and one or more spermathecae (pouches for the reception and storage of seminal fluid). All the reproductive organs are located in the abdomen in both males and females.

Bold jumpers mature in spring, mate in late spring or early summer, then females produce multiple egg sacs over the summer. A female may produce as many as 6 clutches of eggs, each containing 30-170 eggs. Average fecundity is about 200 eggs per female. Later clutches tend to be smaller than earlier ones. Breeding in warmer climates may be more continuous, and adults may survive longer. (Comstock, 1980; Knopf, 1980; Preston-Mafham and Preston-Mafham, 1996; Roach, 1988)

  • Breeding season
    Bold jumpers breed from mid spring to early summer.
  • Range number of offspring
    30 to 600
  • Average number of offspring
    200
  • Average age at sexual or reproductive maturity (female)
    9 months
  • Average age at sexual or reproductive maturity (male)
    9 months

Females make a silk shelter for their eggs, and guard them until they hatch and the spiderlings disperse. (Comstock, 1980; Knopf, 1980; Preston-Mafham and Preston-Mafham, 1996)

  • Parental Investment
  • precocial
  • pre-fertilization
    • protecting
      • female
  • pre-hatching/birth
    • protecting
      • female

Behavior

Like most jumping spiders, bold jumpers hunt alone during the day. Phidippus audax actively watches its prey with its sharp vision. It then sneaks up on its victim and pounces on it. When bold jumping spiders jump, they release a line of webbing for security. This ensures that if a leap fails, there is a safety line that will catch the spider before it falls. Jumping spiders have much better vision than other spiders and are alert for prey and predators.

Where temperatures drop to near or below freezing, juveniles of this species will seek out protected refuge spaces and go dormant during the winter. (Huntley, 1997; Jackman, 1997; Vest, 1999)

Communication and Perception

Bold jumpers have strong visual acuity, and use vision more than most spiders. They also have tactile and chemical senses. They locate prey and predators mainly with their vision.

Visual communication plays a strong role in reproductive behavior. Males use visual signals, such as leg lifting, to communicate with potential mates. Tactile and chemical communication is also of some importance, both for finding mates and for successful mating. (Barnes, 2004; Comstock, 1980; Knopf, 1980; Preston-Mafham and Preston-Mafham, 1996)

Food Habits

Jumping spiders are carnivorous predators. They eat a wide variety of insects and other spiders. They have been studied in cotton fields, where they were found to eat several pest species, including boll weevils, tarnished plant bugs, and adults and larvae of bollworms (moths that attack cotton), including pink bollworms and tobacco budworms. In Idaho, P. audax was observed preying on hobo spiders.

Bold jumping spiders actively hunt during the daytime, but not at night. These spiders use their keen eyesight to locate prey,then they spring upon the prey and bite it, releasing venom. They have been observed to have different stalking strategies for different types of prey, approaching flies from a different angle and jumping from a different distance than they do caterpillars. Male and female bold jumpers hunt differently too. Males prefer smaller prey, and spend less time hunting and feeding. Females prefer larger prey, feed more often, and process prey more to get more food from them. (Barnes, 2004; Huntley, 1997; Jackman, 1997; Vest, 1999)

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods

Predation

Bold jumpers will quickly flee from animals that are too large to eat, jumping down and away or hiding in small crevices. At night they hide in a crevice or small cavity and make a ilk retreat to avoid predators that hunt by touch.

Dragonflies are known to attack them, and birds and lizards do as well. (Knopf, 1980; Preston-Mafham and Preston-Mafham, 1996)

  • Known Predators
    • Dragonflies
    • Lizards
    • Birds (Aves)

Ecosystem Roles

Phidippus audax is an important predator of insects, and as such impacts insect populations.

Economic Importance for Humans: Positive

Phidippus audax has not been reported as having direct economic benefit to humans. However, as predators of many insects that are damaging to cotton crops, these spiders may help to curb populations of these detrimental insects.

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

Bold jumping spiders may bite humans in self-defense if grabbed or pressed. However, this is very rare, and bites are usually asymptomatic to slightly painful. A local reaction might occur, such as an erythematous papule or a small urticarial wheal. (Huntley, 1997)

  • Negative Impacts
  • injures humans
    • bites or stings

Conservation Status

Currently, P. audax and its habitat are not threatened. This spider is quite common and abundant.

Other Comments

The eyes of the bold jumper are very strong, compared to most arthropods. The anterior median eyes form sharp images while the anterior lateral eyes can judge distance. In vertebrates eyes, the lens is moved to adjust the focus, but in jumping spider eyes the lens is fixed and the retina moves. (Wise, 1993)

Contributors

George Hammond (author), Animal Diversity Web.

Nancy Shefferly (editor), Animal Diversity Web.

Katie Knight (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

Glossary

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.

World Map

agricultural

living in landscapes dominated by human agriculture.

arboreal

Referring to an animal that lives in trees; tree-climbing.

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.

carnivore

an animal that mainly eats meat

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

chemical

uses smells or other chemicals to communicate

diurnal
  1. active during the day, 2. lasting for one day.
ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

insectivore

An animal that eats mainly insects or spiders.

internal fertilization

fertilization takes place within the female's body

introduced

referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oceanic islands

islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

saltatorial

specialized for leaping or bounding locomotion; jumps or hops.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

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).

terrestrial

Living on the ground.

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.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

venomous

an animal which has an organ capable of injecting a poisonous substance into a wound (for example, scorpions, jellyfish, and rattlesnakes).

visual

uses sight to communicate

young precocial

young are relatively well-developed when born

References

Barnes, J. 2004. "Arthropod Museum Notes #33, Bold Jumping Spider" (On-line). Arthropod Museum, University of Arkansas. Accessed March 08, 2012 at http://www.uark.edu/ua/arthmuse/boldjump.html.

Comstock, J. 1980. The Spider Book. Ithaca: Cornell University Press.

Huntley, A. 1997. "Phidippus audax: Aggression Unmasked" (On-line). Accessed April 14, 2001 at http://dermatology.cdlib.org/DOJvol3num2/centerfold/phidippus.html.

Jackman, J. 1997. A Field Guide to Spiders & Scorpions of Texas. Houston: Gulf Publishing Company.

Kaston, B. 1978. How to Know the Spiders. Dubuque: Wm. C. Brown Company Publishers.

Knopf, A. 1980. The Audubon Society Field Guide to North American Insects & Spiders. New York: Chanticleer Press, Inc..

Preston-Mafham, K., R. Preston-Mafham. 1996. The Natural History of Spiders. Ramsbury, Marlborough: The Crowood Press.

Roach, S. 1988. Reproductive periods of Phidippus speces (Araneae, Salticidae) in South Carolina. Journal of Arachnology, 16: 95-101. Accessed March 07, 2012 at http://www.americanarachnology.org/JoA_free/JoA_v16_n1/JoA_v16_p95.pdf.

Suman, T. 1964. Spiders Of The Hawaiian Islands: Catalog and Bibliography. Pacific Insects, 6: 665-687. Accessed March 06, 2012 at http://hbs.bishopmuseum.org/pi/pdf/6(4)-665.pdf.

Vest, D. 1999. "Jumping Spiders as Competitors/Predators of the Hobo Spider" (On-line). Accessed April 14, 2001 at http://hobospider.org/jumpings.html.

Wise, D. 1993. Spiders in Ecological Webs. New York: Cambridge University Press.