Volume 47, Number 1,
February 2001:
Checklist of Kansas Jumping Spiders

Text-only version

ISSUE HOME PAGE

ABOUT THIS ISSUE
- about KSN
- about the authors

IN THIS ISSUE
- introduction
- life cycle
- annotated list of Kansas jumping spiders
- salticid spider bite
- mimicry
- enemies: predators and parasites
- care and maintenance of jumping spiders in the lab
- references

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Checklist of Kansas Jumping Spiders
by Hank Guarisco, Bruce Cutler, and Kenneth E. Kinman

LIFE CYCLE
Kansas jumping spiders have admirably adapted their life cycle to the seasons. Mating, reproduction and growth occur predominantly during the spring, summer, and fall. Although feeding has been observed during all seasons, including on mild winter days, jumping spiders become dormant and spend their time in dense, silk retreats during cold winter weather. As cold weather approaches, physiological changes occur in spiders which allow most of them to withstand freezing temperatures. Various sorts of antifreeze compounds are produced and their blood becomes thicker, and therefore, less likely to freeze. Selecting a good location to pass the winter is also very crucial to a salticid's survival. The leaf litter can provide a good winter retreat, especially when blanketed with a layer of snow. At a study site in Douglas County, the 3-spotted jumping spider (P. audax) had a significantly higher winter survival rate on a south-facing slope than on an adjacent north-facing slope. Winter survival may also vary dramatically from year to year and among different species of jumping spiders within the same year.

Salticids and other spiders become more active during the warmer spring weather. Some species, such as P. audax, reach maturity and mate during this season. The males usually mature one or two weeks before the females. During this time, each male seeks out an immature female and guards her. In the field, it is common to find the resting sac of a male next to one containing an almost mature female. When she matures, this male will mate with her. As the eggs develop within her body, the female feeds voraciously. During late spring and early summer, she lays a mass of eggs (sometimes numbering well over 100) in an eggsac within her silk resting chamber. She then guards her eggs from predators and parasites until the young spiderlings emerge about one month later. During the summer months, she may produce as many as six or more eggsacs, each consecutive sac usually containing fewer numbers of eggs. Therefore, by autumn, the populations of spring-maturing salticids consist mostly of juveniles of various sizes and ages. Spiderlings from the same eggsac grow at very different rates, depending upon their food intake.

Some species, such as the Apache jumping spider (P. apacheanus), mature in autumn. In Kansas, this species mates in September, the males die several weeks later, and only the impregnated females overwinter. Populations of Platycryptus undatus, a salticid commonly found under tree bark, consist of juveniles and adults of both sexes throughout the year.