Pest profile

Nursery Web Spider

Pisaurina mira · Araneae: Pisauridae[3]

The nursery web spider is a light brown or orange hunting spider of fields and woodland undergrowth; it's a beneficial predator that doesn't harm people.[1]

Nursery web spider, light brown with a dark stripe down its back, feeding on an insect on white fabric
Nursery web spider, light brown with a dark stripe down its back, feeding on an insect on white fabric. (c) Nick Block, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • It's 1/2 to 3/4 inch long, light brown or orange, usually with a dark stripe running down the front body and abdomen.[1]
  • Its legs aren't banded.[1]
  • Females carry their egg sac under the body, held in their mouthparts.[1]

Look-alikes

Look-alikeHow to tell them apart
Wolf spidersNursery web spiders have a single dark stripe down the back and unbanded legs, and females carry the egg sac in their mouthparts.[1]

Where it lives

Minnesota Extension describes it in fields and the understory plants of wooded areas.[1]

US map: public records from 36 states since 1990 (GBIF).

Biology and life cycle

When the eggs are ready to hatch, the female folds a leaf over and fills the space with silk, building the 'nursery' the spider is named for.[1]

It hunts insects rather than catching them in a web.[1]

Damage and signs

  • It does no damage; it's beneficial as a predator of insects.[1]

Health risk

Minnesota Extension says it doesn't harm people.[1]

Control

Prevention

Trim plants back from the house so spiders don't settle against it and then move indoors.[2]

Traps and physical control

No control is needed outdoors; if one wanders inside, sweep or vacuum it up or move it out, since spiders feed mostly on small insects.[2]

Common questions

Is the nursery web spider dangerous?
No. Minnesota Extension says it doesn't harm people and is a beneficial insect predator.[1]
Why is a spider carrying a big white ball in its jaws?
Female nursery web spiders carry their egg sac in their mouthparts until it's nearly ready to hatch.[1]

Sources

  1. University of Minnesota Extension, “Nursery web spider (What insect is this?).” apps.extension.umn.edu/garden/diagnose/insect/general-curiosity-insects/relatives/medium/nurserywebspider.html (accessed 2026-10-06)
  2. University of California Statewide IPM Program, “Spiders (Pest Notes, Home and Landscape).” ipm.ucanr.edu/home-and-landscape/spiders/ (accessed 2026-10-06)
  3. iNaturalist, “Pisaurina mira taxon page (order and family).” www.inaturalist.org/taxa/84109 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.