Grass Spider, Funnel-Weaver
Agelenopsis sp.
Agelenidae (Funnel-Weaver Spiders), Order Araneae
Physical Description
Small-to-medium spider with a teardrop-shaped abdomen and a distinct elongated cephalothorax. The abdomen often features long, prominent spinnerets extending from the rear, which are a hallmark of this genus. The body has a hairy texture (setae).
Size Estimate
Body length 10-20mm for females, males slightly smaller; leg span approximately 25-50mm (1-2 inches). This appears to be an adult or sub-adult specimen.
Coloration & Markings
Characterized by two dark longitudinal stripes running the length of the cephalothorax, separated by a lighter tan or gray median band. The abdomen often has a chevron or 'herringbone' pattern in shades of brown, gray, and tan.
Web Type
Builds a flat, non-sticky horizontal sheet-like web ending in a funnel-shaped retreat where the spider hides. Webs are typically found in tall grass, low shrubs, or near building foundations.
Eye Arrangement
Eight eyes arranged in two rows of four, typically appearing to form a slightly curved or 'smiling' pattern across the front of the cephalothorax.
Leg Characteristics
Long, slender, and hairy legs with distinct spines (macrosetae). They are usually tan or light brown, sometimes showing faint banding, and are designed for high-speed running on the surface of their webs.
Venom & Safety Information
Venom Information
Possesses venom primarily composed of agelenotoxins (neurotoxic to insects). It is not potent enough to be a significant threat to humans.
Medical Significance
Low medical significance. Bites are rare due to their shy nature. If a bite occurs, it typically results in localized redness, mild swelling, and temporary pain similar to a bee sting.
Safety Recommendations
No special precautions needed. To relocate, use a cup and a piece of paper to gently move the spider back to a garden area. They do not seek out humans to bite.
Habitat & Behavior
Habitat & Range
Found throughout North America. They prefer lawns, gardens, low-lying vegetation, and areas around man-made structures such as siding, corners of windows, and porch stairs.
Behavior & Temperament
Extremely fast runners. They are ambush hunters that wait in their funnel retreat for vibrations on the sheet web. They are shy and generally non-aggressive, retreating to their funnel if disturbed by humans.
Diet & Prey
Insects such as moths, flies, beetles, and crickets. When prey lands on the sheet web, the spider rushes out with incredible speed to bite and drag the prey into the funnel.
Seasonal Activity
Most active from mid-summer through early autumn. This is when their webs become most visible due to morning dew or frost.
Description
The Grass Spider is a ubiquitous sight in North American yards during the late summer months. Known for their incredible speed and distinctive sheet webs, these spiders are efficient predators of garden pests. While often mistaken for wolf spiders, their prominent spinnerets and web-building habits set them apart.
Key Features
Two dark longitudinal stripes on the cephalothorax and long, visible spinnerets at the end of the abdomen.
Similar Species
Wolf Spiders (Lycosidae) - lack the long spinnerets and do not build webs; Hobo Spiders (Eratigena agricola) - have different cephalothorax patterns and shorter spinnerets.
Life Cycle
Females lay egg sacs in crevices or under tree bark in autumn. The mother usually dies before winter, and the spiderlings emerge in the spring. They undergo several molts to reach maturity by late summer.
Ecological Importance
Highly beneficial for pest control, consuming large quantities of insects that are often considered lawn and garden pests.
Conservation Status
Common and widespread; not listed as threatened or endangered.
Interesting Facts
Grass spiders are among the fastest spiders in North America relative to their size; they can clear several feet in a single second when dashing to catch prey or escape a predator.
Photography Tips
Focus on the cephalothorax stripes and the rear spinnerets for identification. Low-angle shots can capture the funnel-web structure, and morning light is best for highlighting dew-covered webs.
Identified: 2026-07-03T17:49:01.234225