Grass Spider

Grass spiders, in the genus Agelenopsis, are common funnel-weaving spiders found throughout much of North America. They have a brown to tan body marked with two dark longitudinal stripes running down the front of the cephalothorax, and long, spiny legs adapted for extremely fast running across their horizontal web.

Their most recognizable feature is their web: a flat, densely woven sheet of silk spread across grass, shrubs, or low structures, which narrows at one edge into a funnel-shaped tunnel retreat where the spider hides. These webs become especially visible on cool, dewy mornings when droplets of moisture cling to every strand, revealing sheets that might otherwise go unnoticed.

Grass spiders are non-aggressive and rely on speed rather than sticky silk to capture prey, sprinting out from their funnel to grab insects that land on the sheet and retreating instantly at the first sign of disturbance. They are important predators of small insects in lawns, gardens, and grasslands.

• Brown to tan coloring with two dark stripes running down the top of the cephalothorax (front body segment)
• Long spinnerets visible at the rear tip of the abdomen, often longer than in similar-looking spiders
• Long, spiny legs built for rapid movement across the web
• Web: large, flat, non-sticky sheet with a funnel retreat at one edge, often seen glistening with dew
• Lookalikes: hobo spider (similar funnel web but different range and pattern), wolf spiders (no web, hunt on the ground)

Common across most of the United States and southern Canada, grass spiders are found wherever there is low vegetation to anchor a horizontal web - lawns, meadows, hedges, rock piles, and the base of shrubs and foundations. Webs are most conspicuous in late summer and autumn.

This spider waits at the mouth of its funnel retreat, sensing vibrations transmitted across the flat sheet web, and darts out with remarkable speed to seize insects that land on the silk before dragging them back into the funnel to feed. It does not use sticky silk, relying instead on the sheer speed of its attack. Diet includes flies, crickets, beetles, and other small arthropods encountered on lawns and in vegetation. Grass spiders are shy and quickly retreat into their tunnel when disturbed rather than confronting a threat.

Mating typically occurs in late summer or early autumn, after which females produce a flattened, disc-shaped silken egg sac that is often hidden in bark, leaf litter, or under debris. Eggs overwinter and spiderlings emerge in spring, dispersing to build their own small funnel webs. The spiders grow through a series of molts over the summer, reaching maturity by late summer, at which point their large, dew-laden webs become most noticeable before the adults die off with the onset of cold weather, completing an annual life cycle.