Animal Diversity Web

Ge­o­graphic Range

Ra­bidosa ra­bida is very com­mon and widely dis­trib­uted. It is often recorded as a wan­der­ing spi­der. It is typ­i­cally found in east to cen­tral Texas and Ok­la­homa, north­ward to Ne­braska. It has fre­quently been traced as far east as Maine and as far south as Florida. (Jack­man, 1997)

• Biogeographic Regions
• nearctic
  • native

Habi­tat

Ra­bidosa ra­bida is­most often found in wooded areas, cot­ton fields, and build­ings. These spi­ders usu­ally re­side among lit­ter, rub­bish, in holes, under rocks, and on low fo­liage in these areas. Some in­di­vid­u­als have been found around ponds or in deep bur­rows with a tur­ret of de­bris. (Jack­man, 1997; Milne and Milne, 1980; Parker, 1982)

• Habitat Regions
• temperate
• terrestrial

• Terrestrial Biomes
• forest

• Other Habitat Features
• urban
• suburban
• agricultural

Phys­i­cal De­scrip­tion

A typ­i­cal rabid wolf spi­der has a dark gray cephalotho­rax with two light lon­gi­tu­di­nal stripes ex­tend­ing across the top and a nar­row light line on each lat­eral mar­gin of the tho­rax. The ab­domen has a dark me­dian band, notched on each side in front of the mid­dle of the ab­domen, with sev­eral pairs of light spots on the rear part of the ab­domen. The first pair of legs is often black or dark brown, and the other legs are brown. Fe­males av­er­age 16 to 21 mm long, Males are typ­i­cally much smaller than fe­males, mea­sur­ing an av­er­age of 13 mm in length. (Com­stock and Gertsch, 1965; Milne and Milne, 1980)

• Other Physical Features
• ectothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger

• Average length

  males, 13 mm; females 21 mm

  in

De­vel­op­ment

Fe­male R. ra­bida drag their egg mass around, hav­ing spun a silken co­coon around the egg mass and at­tached it to spin­nerets. The co­coon dark­ens from shiny white to dirty brown be­fore the eggs hatch.

Spi­der­lings ride on their mother's back until they are ready for dis­per­sal. Egg sacs are from 7 to 10 mm in di­am­e­ter and con­tain from 168 to 365 eggs. (Jack­man, 1997; Milne and Milne, 1980)

Re­pro­duc­tion

Fe­male R. ra­bida re­lease a dragline. Males stum­ble across the line, which leads them to the fe­male. Once court­ing is over, the male spins a ball of silk and then re­leases sperm onto the ball. The fe­male at­taches the ball and drags it along with her until she is fer­til­ized. (Rovner, 1991)

Re­pro­duc­tion in R. ra­bida is one of the most com­monly de­bated and stud­ied areas of the an­i­mal's be­hav­ior. Rabid wolf spi­ders ef­fi­ciently de­tect move­ments. When males and fe­males are in courtship mode, they use a se­ries of dis­plays to in­ter­act and breed. R. ra­bida per­form a se­ries in­ter-bout turns in which one spi­der turns in a given di­rec­tion based upon the di­rec­tion in which the other spi­der turned pre­vi­ously. Pheromones also play a role in these in­tri­cate court­ing rit­u­als. Sci­en­tists have shown that the in­ten­sity of the pheromone is di­rectly re­lated to the turn­ing in males, specif­i­cally the de­gree and time of turn­ing.

Fe­male R. ra­bida drag their egg mass around, hav­ing spun a silken co­coon around the egg mass and at­tached it to spin­nerets. The co­coon dark­ens from shiny white to dirty brown be­fore the eggs hatch.

Spi­der­lings ride on their mother's back until they are ready for dis­per­sal. Egg sacs are from 7 to 10 mm in di­am­e­ter and con­tain from 168 to 365 eggs. (Jack­man, 1997; Milne and Milne, 1980; Rovner, 1991)

• Key Reproductive Features
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• oviparous
• delayed fertilization

• Breeding season

  Breeding occurs from late summer to early fall.

• Range number of offspring

  168 to 365

The spi­der­lings hatch and re­main on the mother's back until they are ready for dis­per­sal. (Jack­man, 1997)

• Parental Investment
• precocial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
• pre-independence
  • protecting
    • female

Lifes­pan/Longevity

Most rabid wolf spi­ders live up to around two years, six months of which is some­times spent on the mother's back. The larger, more fit R. ra­bida can live be­yond two years in sta­ble en­vi­ron­ments. (Com­stock and Gertsch, 1965)

• Range lifespan
  Status: wild

  2 (high) years

• Typical lifespan
  Status: wild

  2 (high) years

Be­hav­ior

Be­cause rabid wolf spi­ders are among the most com­mon spi­ders in the United States, they have adapted to many types of en­vi­ron­ments. These spi­ders are very ag­gres­sive to­wards hu­mans, spi­ders,other an­i­mals and in­sects. Be­cause of their wan­der­ing habits, these spi­ders are sub­ject to a plethora of in­ter­ac­tions be­tween the same and other species. Al­though harm­less to hu­mans, its bite is often feared. (Milne and Milne, 1980)

• Key Behaviors
• terricolous
• motile
• nomadic

Com­mu­ni­ca­tion and Per­cep­tion

Rabid wolf spi­ders com­mu­ni­cate in many dif­fer­ent ways. One way is through the re­lease of pheromones. Both males and fe­males lay out a dragline and de­posit a chem­i­cal at­trac­tor on the line. Male wolf spi­ders in­ter­sect these lines and use their palps to fol­low the line for mat­ing. An­other type of com­mu­ni­ca­tion is web vi­bra­tions. This type of com­mu­ni­ca­tion, known as the sub­stra­tum-cou­pled vi­bra­tion sys­tem, is used mainly by males to at­tract fe­males, but is also used for males to com­mu­ni­cate with one an­other. Es­sen­tially, a male "plucks" the web fibers to play a "song". (Com­stock and Gertsch, 1965; Milne and Milne, 1980; Rovner, 1991; Un­known, 1999)

• Communication Channels
• tactile
• acoustic
• chemical

• Other Communication Modes
• pheromones
• vibrations

• Perception Channels
• visual
• tactile
• acoustic
• vibrations
• chemical

Food Habits

Rabid wolf spi­ders usu­ally pre­fer to eat small in­sects and other in­ver­te­brates. They have been known to eat crick­ets, lo­custs, ants, grasshop­pers and even other spi­ders. R. ra­bida is very strong and is not usu­ally in­tim­i­dated by larger or­gan­isms. These spi­ders are "sit-and-wait" preda­tors. In order to more eas­ily de­tect vi­sual and vi­bra­tory cues from prey, R. ra­bida must re­main mo­tion­less. These spi­ders do not eat solid ma­te­r­ial, so once they over­take the in­sect, they usu­ally suck out liq­uids and nu­tri­ents of their prey. (Jack­man, 1997; Parker, 1982; Rovner, 1989)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• insects
• terrestrial non-insect arthropods

Pre­da­tion

While Ra­bidosa ra­bida is no­madic and moves fre­quently, it does so in a man­ner that is in­con­spicious to larger preda­tors. By stay­ing low in the brush, under lit­ter or ground cover, the spi­der can move ef­fi­ciently and most often re­mains un­de­tected. Wolf spi­ders get their name from they way they stalk their prey slowly and from a dis­tance, which has been as­so­ci­ated with wolves and other wild dogs. (Parker, 1982; Rovner, 1989)

• Known Predators

  • Other Wolf Spiders
  • Dogs
  • Cats
  • Snakes

Ecosys­tem Roles

Ra­bidosa ra­bida has a lim­ited role in th ecosys­tem. Its main job as a preda­tor is to con­trol the boom­ing in­sect pop­u­la­tion. How­ever, as an oc­ca­sional prey species, it may con­tribute to feed­ing other or­gan­isms also.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Al­though it is of lit­tle di­rect ben­e­fit to hu­mans, R. ra­bida is very com­mon among semi-ur­ban and rural areas and is very ac­tive in its pre­da­tion of in­sects. This can be a big ben­e­fit where pests are a prob­lem.

• Positive Impacts
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Ra­bidosa ra­bida has lit­tle ad­verse af­fect on hu­mans out­side of being pests. These spi­ders are not poi­so­nous but have been know to bite un­sus­pect­ing vic­tims.

• Negative Impacts
• household pest

Con­ser­va­tion Sta­tus

Rabid wolf spi­ders are not cur­rently en­dan­gered or at any pre­v­e­lant risk of be­com­ing threat­ened.

• IUCN Red List

  No special status

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

Nancy Shef­ferly (ed­i­tor), An­i­mal Di­ver­sity Web.

Justin Scar­bor­ough (au­thor), South­west­ern Uni­ver­sity, Stephanie Fab­ri­tius (ed­i­tor), South­west­ern Uni­ver­sity.

Ref­er­ences

Com­stock, J., W. Gertsch. 1965. The Spi­der Book. Ithaca, New York: Com­stock Pub­lish­ing Com­pany, Inc..

Jack­man, J. 1997. A Field Guide to Com­mon Texas In­sects. Hous­ton: Gulf Pub­lish­ing Com­pany.

Milne, L., M. Milne. 1980. The Audubon So­ci­ety Field Guide to North Amer­i­can In­sects and Spi­ders. New York: Chan­ti­cleer Press, Inc..

Parker, S. 1982. Syn­op­sis and Clas­si­fi­ca­tion of Liv­ing Or­gan­isms Vol­ume 2. Mc­Graw-Hill Book Com­pany.

Rovner, J. 1991. Turn­ing be­hav­ior dur­ing pheromone-stim­u­lated courtship in wolf spi­ders. An­i­mal Be­hav­iour, 42: 1015-1016.

Rovner, J. 1989. Wolf Spi­ders lack mir­ror-im­age re­spon­sive­ness seen in jump­ing spi­ders. An­i­mal Be­hav­iour, 38: 526-533.

Un­known, 1999. "In­tro­duc­tion to Ethol­ogy" (On-line). Ac­cessed Oct. 3, 2001 at http://​cas.​bellarmine.​edu/​tietjen/​Ethology/​introduction_​to_​ethology.​htm.