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 Phidippus apacheanus    Chamberlin and Gertsch, 1929

A Jumping Spider 


MN Status:
special concern
Federal Status:
none
CITES:
none
USFS:
none

Group:
spider
Class:
Arachnida
Order:
Araneae
Family:
Salticidae
Habitats:

(Mouse over a habitat for definition)


Phidippus apacheanus

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Map Interpretation

Map Interpretation

  Synonyms

Phidippus insolens

  Basis for Listing

Phidippus apacheanus is a common species in the southern United States from Florida to California. However, it appears to be of local occurrence north of 30° to 35°N latitude. It is rare in the Upper Midwest, known only from a few locations in southwestern Wisconsin and southeastern Minnesota. In Minnesota, the species is limited to undisturbed native prairie, a rapidly diminishing habitat type. Phidippus apacheanus has been collected at just three sites in the state, the most recent being from 1982. It was subsquently listed as a special concern species in Minnesota in 1996. Special concern spider species are those known from three or more sites in Minnesota, but with significant range restrictions or particular habitat associations that make their populations appear vulnerable from a conservation standpoint.

  Description

Phidippus apacheanus is a large, stocky, showy jumping spider. The males are black with bright red-orange backs and rings on their legs. The females are similar, but also have a few black markings on their backs. This species is often over 1 cm (0.4 in.) long, and the front of the jaws are iridescent.

  Habitat

In Minnesota, P. apacheanus is only known from dry prairie in the southeastern corner of the state, a diminishing habitat type. Elsewhere, the species has been found in a variety of open habitats, including sagebrush flats in Utah (W. Ehmann, pers. comm.).

  Biology / Life History

Jumping spiders do not spin webs for catching prey. Instead, they construct small tent-like silken retreats under rocks or logs, or on plants, which they use at night and during hibernation. The females will also lay their eggs in them. Jumping spiders are most active during the day, and they prefer sunshine. They tend to stay in their retreats on cloudy or rainy days. Jumping spiders are generally interested in whatever approaches them, and will often turn and face human observers, and may even advance towards them. They are generally harmless to people.

Jumping spiders have four pairs of eyes, with the pair of large principal eyes giving them better vision than other spiders. The forward-looking placement of this pair of eyes provides binocular vision, enabling them to judge distances accurately, and they are able to identify prey, predators, and mates from up to a foot away (Weber 2002). Physiological and behavioral experiments have demonstrated that they have color vision, possibly extending into the ultraviolet range.

Jumping spiders feed primarily on insects, although some may feed on web-building spiders. They will also feed on other jumping spiders, usually those that are smaller than themselves. Jumping spiders actively stalk their prey instead of snaring it in a web. They may however, steal insects snared by the webs of other spiders. Jumping spiders hunt primarily during the day, using their keen eyesight to find prey. Having spotted a potential victim, a jumping spider will slowly stalk the prey until it is within jumping distance. Then, it lifts its front legs and pounces. Like all spiders, jumping spiders move their legs not by muscular contractions but by changing the pressure of the fluid within them. This hydraulic system enables them to jump up to several times their body length without having large, muscular legs. Before jumping, the spider always affixes a silk safety line to whatever it is jumping from; in case it falls it can climb back up this tether.

The visual capabilities of jumping spiders that are critical to their performance as hunters also support complex courtship behaviors. Males often differ in appearance from females and my have colorful, sometimes iridescent modifications to their bodies, front legs, or mouthparts. The parts of the male's body that are used in courtship are often conspicuously colored. In many jumping spider species, the males perform courtship dances in front of the female that are specific to each species. The male's movements range from a slight lifting of a leg to complex movements, such as bobbing their bodies, twitching their abdomen, performing zigzag movements, waving their front legs, or flashing their mouthparts into the eyes of the females. Some male jumping spiders may also have auditory signals which when amplified sound like buzzes or drum rolls. It is presumed that females choose mates based on their courtship dances. After mating, females lay their eggs in their silken retreat, and will often guard their eggs and newly hatched young.

Because of the size and coloration of P. apacheanus, it has been suggested that this species is a generalized wasp mimic. Other members of the same genus have been studied for specific courtship and foraging behaviors (see Jackson and Pollard 1997).

  Conservation / Management

The best time of year to survey for P. apacheanus is from August through September. Though P. apacheanus has a large range, the scant Minnesota records define its northernmost extent, suggesting an opportunity to learn more about this species' ecological tolerances. Although remnants of natural areas may often be too small or isolated for some rare vertebrates, they may be suitable for maintaining invertebrates. Each new locality for a species adds to the suite of management options for their conservation and may even guide new land designations or acquisitions. Benign to humans, diverse, colorful, and behaviorally complex, jumping spiders may be good ambassadors for their kin and invertebrates in general.

  Conservation Efforts in Minnesota

Surveys of all known localities of P. apacheanus conducted in early summer 1996 were unsuccessful at relocating this species (Ehmann and Boyd 1997). Late-season sampling, including hand searches, may yield new records. Any new records, including date of collection, behaviors observed, and habitat details will be of high interest.

  References

Ehmann, W. J. 2002. Conservation biology of special concern jumping spiders (Araneae: Salticidae) of Minnesota. Final Report submitted to the Natural Heritage and Nongame Research Program, Minnesota Department of Natural Resources. 11 pp.

Ehmann, W. J., and B. E. Boyd. 1997. Surveys for proposed special concern jumping spiders of Minnesota. Final report submitted to the Minnesota Department of Natural Resources. Unpaged.

Foelix, R. F. 1996. Biology of spiders. Oxford University Press, New York. 330 pp.

Forster, L. M, and M. R. Forster. 1999. How do jumping spiders catch up on their prey?: a model for pursuit behaviour. (Araneae; Salticidae) - a preliminary draft. . Accessed 16 Aug 2006.

Jackson, R. R., and S. D. Pollard. 1997. Jumping spider mating strategies: sex among cannibals in and out of webs. Pages 340-351 in J. C. Choe and B. J. Crespi, editors. Mating systems in insects and arachnids. Cambridge University Press, Cambridge, Massachusetts.

Maddison, W. 2006. Jumping spiders of American north of Mexico. . Accessed 16 Aug 2006.

Richman, D. B., and B. Cutler. 1977. A list of jumping spiders (Araneae: Salticidae) of the United States and Canada. Peckhamia 1:82-109.

Weber, L. 2002. Spiders of the North Woods. Kollath-Stensaas Publishing, Duluth, Minnesota. 205 pp.

Wikipedia contributors. 2010. Jumping spider. Wikipedia, The Free Encyclopedia. <http://en.wikipedia.org/wiki/Jumping_spider>. Accessed 15 April 2010.