Grass Spiders – Funnel Weavers

There are about 300 different species of Grass spiders in North America. During spring and summer, Grass spiders are common around the home and in the landscape. Grass spiders are harmless to humans because their chelicerae (mouth parts) are too small to penetrate human skin. Grass spiders are also known as “Funnel-weavers” due to the type of web they weave for catching prey. Funnel-weaver spiders belong to the family Agelenidae. These spiders may not hurt humans but they sure do create a lot of webs in the grass and on shrubs.

Grass spider (Agelenopsis aperta) “Funnel-weaver”

Grass Spider Habits and Habitat

The Grass spider is a “sit-and-wait” type predator. It makes funnel webs in grassy areas, in low plants, shrubs and on top of hedges. Grass spider webs are easily observed in the spring and summer, especially after an early morning dew. The Grass spider waits patiently within the funnel portion of its web until an insect gets tangled in the upper, sheet-like area, then the spider scurries out to bite and paralyze its victim. Once the insect is immobilized, the Grass spider pulls its prey down into the funnel where she can feed at leisure – It’s the female Grass spider that makes funnel webs.

Grass spiders may blend well with grass but their
webs are easy to see.

Mating and Reproduction

Male Grass spiders wander in search of females; they mate, and then die shortly thereafter. The female creates and stays in the web catching prey and building up her strength to mate and lay her eggs. In the fall, female Funnel-weavers deposit their egg sacs in narrow areas like under the bark of a tree or between rocks. They soon die, sometimes, still clinging to their eggs.

A Grass spider coming out of its Funnel web in search of prey.

Grass spider eggs hatch during the spring and become adults by mid-summer. You can tell how old a spider is by the size of its web; older spiders have layers and layers of flat web spread out like a sheet, up to 12 inches wide, with the funnel to one side of the web.

Grass spiders have eight eyes, two on the top row,
four in the middle, and two on the bottom row.

Pest Control for Grass Spiders

Grass spiders are not harmful to humans but sometimes they may find their way indoors, usually in search of food. Female Grass spiders, however, build and spend their days within the funnel portion of their web. Most people consider their multiple webs an eyesore, but again, they are not harmful and they are beneficial in that they do eat insects. The best way to control Grass spiders is to destroy their webs and treat for insects – their food source.  Hearts Pest Management will treat for both spiders and insects.

Call today at 1-800-986-1006 for help with a spider infestation. You’re also welcome to complete the form below and a caring Hearts Pest Management representative will contact you shortly.

References
University of California Agriculture and Research Department
Cranshaw, Whitney, Garden Insects of North America, Princeton University Press, Princeton, New Jersey, 2004.