Grass Spider, Funnel Weaver
Agelenopsis sp.
Agelenidae (Funnel Weavers), Order Araneae. Characterized by long, visible spinnerets and sheet-like webs.
Physical Description
Elongated, pear-shaped body with a distinct cephalothorax and a tapering abdomen. The surface is covered in fine hairs (setae). A notable feature is the pair of long, prominent spinnerets extending from the rear of the abdomen.
Size Estimate
Body length 10-20mm; leg span 25-50mm. This appears to be an adult or sub-adult female based on abdomen size and proportions.
Coloration & Markings
Tan to grayish-brown base with two dark longitudinal stripes running down the cephalothorax. The abdomen features a central lighter stripe often bordered by darker, chevron-like or spotted patterns.
Web Type
A horizontal, non-sticky sheet web that tapers into a funnel-shaped retreat at one end. Built in grass, low shrubs, or building corners.
Eye Arrangement
Eight eyes arranged in two rows that appear strikingly curved (procurved), creating a somewhat circular or hexagonal grouping when viewed from the front.
Leg Characteristics
Long, slender, and hairy legs with noticeable spines. They are built for extreme speed across the surface of their silk sheets.
Venom & Safety Information
Venom Information
Contains agelenitoxin, which is highly effective against insects but has very low toxicity to mammals.
Medical Significance
Harmless to humans. Bites are rare and usually cause only minor localized redness or itching, similar to a mosquito bite or bee sting.
Safety Recommendations
No action is usually necessary. If one enters a home, they can be easily moved outside using a cup and paper. They do not pose a danger to pets or children.
Habitat & Behavior
Habitat & Range
Common across North America; found in lawns, gardens, low bushes, and occasionally tall grass. They often build near foundations or windowsills.
Behavior & Temperament
Extremely fast runners but very timid. They spend most of their time in the funnel retreat and dart out only when vibrations signal prey on the sheet. They are not aggressive towards humans.
Diet & Prey
Generalist predators eating grasshoppers, moths, flies, and beetles. They use speed to overtake prey rather than sticky silk.
Seasonal Activity
Most visible in late summer and early autumn when webs are largest and mating occurs.
Description
The Grass Spider is the architect of the dew-covered morning webs often seen on lawns. They are incredibly fast hunters that rely on acoustics and vibration to detect prey landing on their platform-like webs.
Key Features
Prominent elongated spinnerets at the rear of the abdomen and two dark stripes on the cephalothorax.
Similar Species
Wolf Spiders (Lycosidae) - which lack the long spinnerets and do not build sheet webs; Nursery Web Spiders (Pisauridae) - which have a different eye arrangement.
Life Cycle
Females lay disc-shaped egg sacs in fall and often die after frost. Spiderlings emerge in spring. They typically have a one-year lifespan.
Ecological Importance
Critical for natural pest control in suburban and agricultural landscapes, significantly reducing populations of leaf-eating insects.
Conservation Status
Not evaluated by IUCN, but widespread and common with stable populations.
Interesting Facts
Despite the large, intimidating webs, these spiders are one of the most beneficial garden predators and can run at speeds up to 1.5 feet per second.
Photography Tips
Focus on the elongated spinnerets and the head area. Best photographed in the early morning when dew makes the web sheet highly visible.
Identified: 2026-07-12T08:27:34.415989