American Nursery Web Spider
Pisaurina mira
Pisauridae (Nursery Web Spiders), Order Araneae
Physical Description
Elongated body shape with a distinctively long cephalothorax and abdomen. The cephalothorax features a lighter median band flanked by darker brown lateral stripes. The legs are very long and slender, held in a characteristic paired grouping when resting.
Size Estimate
Body length ranges from 12 to 20 mm with a leg span reaching up to 50 to 75 mm, typical for an adult female specimen.
Coloration & Markings
Variable coloration ranging from yellowish-tan to dark brown. Usually features a broad, pale median band running down the carapace and abdomen, bordered by darker brown or reddish stripes.
Web Type
Does not build a web to catch prey. Instead, females construct a silken nursery web in tall grass or leaves to protect their egg sacs and spiderlings.
Eye Arrangement
Eight eyes arranged in two slightly curved rows, of roughly equal size, which helps distinguish Pisauridae from wolf spiders.
Leg Characteristics
Long, slender legs with distinct spines. When resting on vertical surfaces, they frequently hold their first two pairs of legs paired closely together.
Venom & Safety Information
Venom Information
Contains mild venom used to subdue insect prey. It is not considered dangerous or medically significant to humans.
Medical Significance
Harmless to humans. Bites are extremely rare and typically result only in mild localized pain or swelling similar to a mosquito bite.
Safety Recommendations
No special precautions needed. If found indoors, easily relocated outside using a cup and a piece of paper.
Habitat & Behavior
Habitat & Range
Found throughout the eastern and central United States and parts of Canada. Prefers tall grass, brush, shrubbery, woodland edges, and frequently wanders onto human structures.
Behavior & Temperament
Active nocturnal hunters that do not use webs for prey capture. Docile and non-aggressive, preferring to flee or drop to the ground when disturbed rather than bite.
Diet & Prey
Generalist predator feeding on various insects including grasshoppers, flies, beetles, and other small spiders.
Seasonal Activity
Most active during spring and summer months when mating occurs and females guard nursery webs in vegetation.
Description
The American Nursery Web Spider is a graceful and agile hunter often encountered in gardens and woodland margins. Known for carrying their egg sacs and building protective silken nurseries for their young, they play a beneficial role in controlling insect populations.
Key Features
Distinctive longitudinal striping on the carapace, long slender legs held in pairs, and the habit of carrying egg sacs in the mouthparts rather than attached to spinnerets.
Similar Species
Wolf spiders (Lycosidae), which carry egg sacs attached to their spinnerets and have a different eye arrangement featuring two very large principal eyes.
Life Cycle
Females carry their egg sacs in their chelicerae until just before hatching, then construct a silken tent (nursery web) and stand guard until the spiderlings disperse.
Ecological Importance
Acts as an effective natural predator, helping to regulate populations of garden and woodland insects.
Conservation Status
Not threatened; stable and widespread across its natural geographic range.
Interesting Facts
Male nursery web spiders often present potential mates with a nuptial gift, such as a wrapped insect, to distract the female from cannibalism during courtship.
Photography Tips
Photograph from the side or top using natural diffused light. Capture the distinct carapace striping and eye arrangement for reliable identification.
Identified: 2026-09-01T22:41:35.599460