American Grass Spider, Funnel Weaver
Agelenopsis species (most likely)
Agelenidae (Funnel Weavers), Order Araneae. Characterized by prominent elongated spinnerets and the construction of flat, non-sticky sheets with a funnel-shaped retreat.
Physical Description
A medium-sized spider with a distinct elongated body. The cephalothorax is teardrop-shaped and the abdomen is oval, tapering toward the rear where two prominent, long spinnerets are visible. The body has a somewhat 'hairy' appearanced due to fine bristles (setae).
Size Estimate
The specimen appears to have a body length of approximately 10-15mm. Total leg span likely reaches 25-35mm. This appears to be an adult or sub-adult based on the proportions relative to the mesh.
Coloration & Markings
Features two prominent dark longitudinal stripes running down the cephalothorax, separated by a lighter tan or gray band. The abdomen displays a mottled or chevron-like pattern in brown, tan, and gray tones. The legs are generally uniform tan or light brown, sometimes with faint darker banding.
Web Type
Funnel web. These spiders build flat, horizontal sheet webs with a characteristic tube-like retreat in one corner. The silk is not sticky; the spider relies on speed to capture prey that lands on the sheet.
Eye Arrangement
Eight eyes arranged in two rows of four, typically appearing to curve slightly. The arrangement is characteristic of Agelenidae, though not fully visible in the provided image.
Leg Characteristics
Strong, moderately long legs equipped with prominent black spines (macrosetae). They are designed for running rapidly across their silk sheets and ground surfaces.
Venom & Safety Information
Venom Information
Neurotoxic venom specialized for paralyzing small insects. The venom is not considered medically significant to humans; its potency is very low and generally ineffective against large mammals.
Medical Significance
Low danger level. A bite typically results in minor localized pain, redness, and swelling similar to a bee sting, resolving quickly. No special medical attention is usually required unless an allergic reaction occurs.
Safety Recommendations
These spiders are harmless. If found inside, they can be easily relocated using a cup and a piece of paper. To prevent entry, ensure window screens are intact and gaps under doors are sealed.
Habitat & Behavior
Habitat & Range
Found throughout North America. They are ubiquitous in gardens, tall grass, low shrubs, and frequently enter homes near windows, door frames, or basements during the autumn months.
Behavior & Temperament
Extremely fast runners and active hunters that wait in their funnel retreat. They are generally timid and will retreat rapidly if disturbed. They are not known to be aggressive toward humans and usually bite only if trapped against skin.
Diet & Prey
Primary diet consists of small insects like flies, crickets, and beetles that land on their web. They utilize vibration sensing to detect prey, rushing out to deliver a paralyzing bite before dragging the prey into the funnel.
Seasonal Activity
Most visible in late summer and early autumn when they reach full size and their webs are coated in morning dew. This is also when males wander in search of mates.
Description
The Grass Spider is a staple of temperate gardens, easily identified by the lightning-fast speed at which it darts across its characteristic sheet web. Often mistaken for more dangerous spiders due to its size and speed, it is a beneficial neighbor that works tirelessly to keep insect populations in check.
Key Features
Long, visible spinnerets protruding from the end of the abdomen and two dark parallel stripes on the cephalothorax.
Similar Species
Often confused with Wolf Spiders (Lycosidae), which lack the long spinnerets and do not build webs, and Hobo Spiders (Eratigena agricola), which have less distinct cephalothorax markings.
Life Cycle
Females lay egg sacs in late summer or autumn in protected crevices. The mother typically dies in the winter, and spiderlings emerge in the spring. They undergo several molts before reaching maturity in mid-to-late summer.
Ecological Importance
Crucial for natural pest control. They consume a vast number of agricultural and household pests, serving as an important link in the garden food web.
Conservation Status
Not evaluated by IUCN, but populations are stable and widespread throughout their range; they are not considered threatened.
Interesting Facts
Grass spiders are some of the fastest spiders for their size, capable of reaching speeds that make them a blur to the human eye when they sense prey or a threat.
Photography Tips
Focus on the dorsal (top) view to capture the stripes on the head and the spinnerets at the tail. Side-view photos of the eye arrangement are also helpful for genus confirmation.
Identified: 2026-06-30T12:29:22.575166