Grass Spider

Agelenopsis species are agelenid funnel weavers, 10–20 mm, with a tan-brown carapace carrying two dark longitudinal stripes, a striped abdomen and conspicuously long, prominent posterior spinnerets that project like tails. Legs are long and hairy and the body is built for speed. Eggs are laid in flat, disc-shaped sacs in late summer and autumn under bark, siding and debris, overwintering to hatch in spring; most adults die at first hard frost, giving one generation per year with a strong autumn adult peak.

Grass spiders spin a dense horizontal sheet web with a funnel retreat at one edge, sitting head-out in the funnel and sprinting across the sheet to seize prey that stumbles onto it. The silk is not sticky — capture depends entirely on speed. They are shy, fleeing into the funnel or dropping away at the slightest disturbance, and bites on people are exceptionally rare and medically trivial. Males wander widely in late summer searching for mates, which is when they most often blunder indoors and generate service calls.