Order: Araneae


All spiders have two body segments, eight legs, and lack antennae. They typically have six to eight eyes arranged in two rows and modified mouthparts called pedipalps, which are spherical and enlarged on male spiders. Collectively, they range in size and color, depending on family and species. For example, jumping spiders (family: Salticidae) are relatively small, measuring about 4-12 mm (1/7-1/2 inch) long, and have abundant body hairs, while wolf spiders (family: Lycosidae) are 1.3-5 cm (1/2-2 inches) long. Generally, male spiders are smaller than female spiders. Both jumping spiders and wolf spiders are usually black, brown, or grey, though some species of jumping spider are very colorful. Other spiders commonly found in gardens and landscapes include orb weaving spiders (family: Araneidae), funnel-web spiders (family: Agelenidae), crab spiders (family: Thomisidae), woodlouse spiders (family: Dysderidae), and ground spiders (family: Gnaphosidae).

Quick Facts

  • Spiders are beneficial arthropods that feed on many different insect pests indoors and outdoors.
  • In Colorado, the western widow spider (Latrodectus hesperus) and brown recluse spider (Loxosceles reclusa) are the only species considered dangerous to humans.
  • Spider control is rarely necessary, and they are often the most important biological control agent of garden pests.
Wolf Spider

Wolf spider. Image credit: David Cappaert, Bugwood.org 

Jumping spider

Immature male black widow spider. Note the enlarged pedipalps (arrows). Image credit: Joseph Berger, Bugwood.org

Crab Spider

Jumping spider. Image credit: Florida Division of Plant Industry, Florida Department of Agriculture and Consumer Services, Bugwood.org

Crab Spider

Crab Spider. Image credit: Whitney Cranshaw, Colorado State University, Bugwood.org 

Crab Spider

Orb weaving spider. Image credit: Joseph Berger, Bugwood.org

Life history and habits

All spiders are generalist predators that feed on insects or other arthropods. There are many spiders – wolf spiders, crab spiders, jumping spiders – that do not build webs but instead move about and hunt their prey on soil or plants. These less conspicuous spiders can be important in controlling insect pests such as beetles, caterpillars, leafhoppers, and aphids.

Female spiders lay eggs in clusters and most species cover their eggs with a protective sheet of silk. Some spiders carry eggs on their back until they hatch. Immature spiders are called spiderlings and often disperse by climbing to the top of a nearby object and produce long silk filaments, which they use to ride wind currents to new locations. This dispersal mechanism is known as ballooning.

Spiders as biocontrol agents

Spiders are recognized as important biological control agents for managing pests indoors and outdoors. Indoors, spiders can help reduce the numbers of undesirable insects such as flies, mosquitoes, and moths. In landscapes and outdoor gardens, spiders can be important predators of insect pests such as beetles, caterpillars, leafhoppers, and aphids. Research also suggests that spiders are very abundant in grain crops, and they may cause high mortality of certain pests such as the diamondback moth (Plutella xylostella).


Killing spiders should be avoided if possible. When spiders are found in the home, they can be carefully removed and placed outdoors away from the building. Cultural or mechanical controls can be used against pests to conserve populations of these natural enemies. When insecticides are used, their selectivity and the timing of applications should be considered.


CSU. (n.d.). Wolf Spiders. Colorado State University – Extension. Available https://planttalk.colostate.edu/topics/insects-diseases/1485-wolf-spiders/#:~:text=Wolf%20spiders%2C%20among%20the%20largest,food%2C%20mates%20or%20wintering%20sites.

Stewart, C., and N. Coverstone. 2004. Beneficial Insects and Spiders in Your Maine Backyard. University of Maine Cooperative Extension. Available https://extension.umaine.edu/publications/7150e/

USU. 2013. Spiders. Utah State University – Extension. Available https://extension.usu.edu/pests/uppdl/files/ezplug/uploads/Spiders_2013PP.pdf

USU. (n.d.). Jumping Spiders. Utah State University – Extension. Available https://extension.usu.edu/pests/schoolipm/structural-pest-id-guide/jumping-spiders

Huang, X., X. Quan, X. Wang, Y. Yun, and Y. Peng. 2018. Is the spider a good biological control agent for Plutella xylostella (Lepidoptera: Plutellidae)? Zoologia 35:1-8. Available https://zoologia.pensoft.net/article/23481/

Full Jumping Spider Fact Sheet

Download or view the Jumping Spider PDF fact sheet for your reference.