Grass Spider, American Grass Spider, Funnel-Web Spider
Agelenopsis sp.
Agelenidae (Funnel-Weavers), Order Araneae
Physical Description
Elongated, slender body with a distinctively pointed abdomen ending in prominent, two-segmented spinnerets. The cephalothorax is teardrop-shaped and relatively flat, while the abdomen is oval and tapers sharply.
Size Estimate
Body length 10-20mm (females 15-20mm, males 10-18mm). Leg span typically 25-50mm. This specimen appears to be a sub-adult or adult based on the prominent spinnerets.
Coloration & Markings
Characterized by two dark longitudinal stripes running down the cephalothorax on a light tan or greyish background. The abdomen features a central, darker chevron or herringbone pattern flanked by lighter tan areas.
Web Type
Builds a large, horizontal, non-sticky sheet web that leads to a funnel-shaped retreat in one corner. Webs are typically built in low vegetation, grass, or evergreen shrubs.
Eye Arrangement
Eight eyes arranged in two rows that are strongly procurved (arched forward), appearing almost like three rows: 2:4:2 or a circular pattern. This provides nearly 360-degree detection of movement.
Leg Characteristics
Long, hairy, and bristly legs with numerous spines (macrosetae). Usually tan or light brown with faint darker banding. The legs are designed for extremely fast running across the top of their sheet webs.
Venom & Safety Information
Venom Information
The venom is neurotoxic but specialized for paralyzing insects. It is not considered toxic or dangerous to humans or pets.
Medical Significance
Harmless. Bites are extremely rare because the spider is very fast to retreat. If a bite occurs, it typically results in mild redness or localized itching similar to a mosquito bite.
Safety Recommendations
No action is typically needed as they are beneficial. If found indoors, they can be safely relocated using the cup-and-paper method. They pose no threat to children or pets.
Habitat & Behavior
Habitat & Range
Common throughout North America (USA, Canada, Mexico). They prefer lawns, meadows, gardens, and dense ornamental shrubs like the juniper/cypress shown in the image.
Behavior & Temperament
Extremely fast runners and shy. They sit at the mouth of their funnel retreat, darting out rapidly to grab prey that lands on the sheet. They are non-aggressive toward humans and will retreat if disturbed.
Diet & Prey
Generalist predators feeding on various insects such as flies, crickets, moths, and beetles. They do not wait for prey to get stuck (the web isn't sticky); they rely on speed to ambush prey before it leaves the sheet.
Seasonal Activity
Most visible in late summer and autumn when they reach full size and their large webs become more prominent, often coated in morning dew.
Description
The Grass Spider is a master of the low canopy, easily identified by its lightning-fast speed and the iconic funnel retreats it weaves into garden foliage. This specimen is perfectly camouflaged within the dense needles of a conifer, utilizing the branch structure to anchor its expansive sheet web.
Key Features
Elongated spinnerets (extending past the end of the abdomen), two dark longitudinal stripes on the cephalothorax, and the distinct funnel-shaped web.
Similar Species
Wolf Spiders (Lycosidae) are often confused with Grass Spiders but lack the long spinnerets and do not build funnel webs. Barn Funnel Weavers (Tegenaria) are similar but usually darker with more mottled markings.
Life Cycle
Females produce a white, disc-shaped egg sac in autumn and die shortly after. The eggs overwinter and hatch in spring. Spiderlings often undergo ballooning to disperse. They typically live for only one year.
Ecological Importance
Highly beneficial as natural pest control. They consume large quantities of garden and lawn pests that might otherwise damage turf and ornamental plants.
Conservation Status
Not evaluated by IUCN, but considered stable and abundant throughout their range.
Interesting Facts
Despite their sheet webs not being sticky, they are among the fastest spiders; their speed allows them to tackle prey before it can fly away. The 'funnel web' of this North American species should not be confused with the unrelated and dangerous Sydney Funnel-Web Spider of Australia.
Photography Tips
Focus specifically on the tail end to capture the long spinnerets. To highlight the web, photograph during the early morning when dew or mist makes the silk strands clearly visible against the foliage.
Identified: 2026-06-11T19:33:33.484797