Agelenopsis naevia

(Walckenaer, 1841)

Dark-legged Grass Spider

Agelenopsis naevia is a of funnel-web in the Agelenidae, commonly known as the Dark-legged Grass Spider. It is found in the United States and Canada. Like other members of its , it constructs flat, sheet-like webs with a funnel-shaped retreat where the spider waits to ambush . The species was first described by Walckenaer in 1841.

Common Spiders U.S. 239 by James Henry Emerton (1847 – 1931). Used under a Public domain license.

Hentz Plate 20 (cropped) by James Henry Emerton
. Used under a Public domain license.

Common Spiders U.S. 223-5 by James Henry Emerton (1847 – 1931). Used under a Public domain license.

Pronunciation

How to pronounce Agelenopsis naevia: /ˌæɡəˌlɛˈnɒpsɪs ˈniːviə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from Hololena by long held parallel to each other (Hololena has short spinnerets directed inward). Differs from Calilena by spinneret orientation and geographic range. Separated from other Agelenopsis by subtle morphological details of and coloration patterns, particularly the dark leg coloration that gives this species its . The flat, horizontal web with a funnel retreat at one end is characteristic of the but not unique to this species.

Images

Appearance

-sized with body length typically 10-20 mm for females, slightly smaller for males. bears two parallel or converging dark stripes on a pale background. displays a central reddish or brownish running its length, often bordered by pale, wavy . Legs are annulated with alternating bands of light and dark coloration. are notably long and held parallel to each other, a distinguishing feature from the related Hololena.

Habitat

Occurs in grassy areas, lawns, gardens, and shrubbery where it can construct its sheet webs close to the ground or vegetation. Webs are often built in protected locations among plants, rocks, or debris. and mature males may wander and enter human structures.

Distribution

United States and Canada. Distributed across North America with records from multiple U.S. states and Canadian provinces.

Diet

. Preys on small and other that blunder onto its web.

Behavior

Constructs flat, hammock- or bowl-shaped sheet webs with a funnel-like retreat in one corner. The web lacks sticky capture threads; instead, a tangle of threads above the sheet intercepts flying , knocking them onto the platform. The detects vibrations through the web and executes rapid attacks to subdue , dragging victims back into the funnel to feed. When threatened, the spider retreats rapidly down the funnel. Sexual has been observed in the , with females consuming males after mating, particularly when hungry or aggressive, resulting in increased weight and hatching success.

Ecological Role

of small and . Serves as for larger predators including birds and other arthropods. Contributes to of insect in grassy and garden .

Human Relevance

Generally harmless to humans; bites are rare and typically result only in mild, transient . May enter homes as wandering or mature males, causing occasional alarm but posing no significant threat. Webs become conspicuous on foggy mornings when dew condenses on , revealing the abundance of these in residential landscapes.

Similar Taxa

Hololena spp.Also Agelenidae with similar web architecture, but distinguished by short, inward-directed versus long, parallel spinnerets in Agelenopsis. Hololena is restricted to western North America.
Agelenopsis pennsylvanicaCongeneric grass with overlapping range; distinguished by subtle differences in coloration and genital , with A. naevia having darker leg coloration.
Calilena spp.Western Agelenidae with long , but spinneret orientation and geographic distribution differ.

More Details

Web Structure

The web architecture is specialized for interception rather than adhesion. Non-sticky sheet webs rely on the 's speed and rather than passive capture.