Grass Spider, Funnel Weaver
Agelenopsis species
Agelenidae (Funnel Weavers), Order Araneae. Key family feature includes the prominent, elongated spinnerets at the rear of the abdomen.
Physical Description
Elongated, teardrop-shaped abdomen with a flat cephalothorax. The body is covered in fine hairs (setae) giving it a matte appearance. Notable for two long, prominent spinnerets extending from the tail end.
Size Estimate
Body length 10-20mm; leg span 25-50mm. This appears to be a sub-adult or adult specimen.
Coloration & Markings
Tan to grayish-brown base with two distinct dark longitudinal stripes running the length of the cephalothorax. The abdomen features a central lighter band bordered by darker, wavy, or chevron-like patterns.
Web Type
Dense, horizontal sheet web that tapers into a funnel-shaped retreat at one end. Built in grass, shrubs, or corners of structures. The web is non-sticky; it relies on speed to capture prey.
Eye Arrangement
Eight eyes arranged in two rows, with the rows appearing strongly procured (arched), often looking like three rows (2-4-2) depending on the angle.
Leg Characteristics
Long, slender legs with visible spines (macrosetae) used for traction. Usually light brown with faint dark banding or spotting.
Venom & Safety Information
Venom Information
Neurotoxic venom designed to paralyze small insects quickly. The venom is not considered potent or dangerous to humans.
Medical Significance
Harmless. Bites are extremely rare because the spider is timid. If a bite occurs, it typically results in mild redness, localized itching, or minor swelling similar to a bee sting.
Safety Recommendations
No control is necessary as they are beneficial. If found indoors, they can be easily moved outside using the 'cup and paper' method. They are unlikely to bite unless handled roughly.
Habitat & Behavior
Habitat & Range
Found throughout North America. Preferred habitats include low-lying vegetation, gardens, window wells, and foundations of buildings.
Behavior & Temperament
An ambush hunter that waits in the back of its funnel retreat. Extremely fast runners but very shy. They will flee into their retreat at the slightest vibration and are not aggressive toward humans.
Diet & Prey
Generalist predators feeding on various insects such as crickets, flies, and moths that land on their horizontal sheet web.
Seasonal Activity
Most active from late summer to early autumn when adults reach full size and males wander to find mates.
Description
The Grass Spider is a common and fascinating architect of the garden. Known for its 'lightning-fast' speed, it is a master of the sheet web, providing excellent natural pest control around homes.
Key Features
Elongated spinnerets, two dark parallel stripes on the cephalothorax, and very fast movement.
Similar Species
Wolf Spiders (Lycosidae) are often confused with them but lack the long spinnerets and build no webs. Fishing Spiders (Dolomedes) are larger and have a different eye arrangement.
Life Cycle
Females lay egg sacs in autumn, often in crevices or under bark. The female dies shortly after. Spiderlings hatch in spring and may disperse via ballooning.
Ecological Importance
Significant role in controlling agricultural and garden pests like moths and grasshoppers. They serve as a food source for birds and wasps.
Conservation Status
Common and widespread; not listed on the IUCN Red List. No immediate threats known.
Interesting Facts
Despite their speed, they are virtually blind and rely almost entirely on vibrations across their web to detect the size and location of their prey.
Photography Tips
Focus on the long spinnerets and the head stripes. Use a fast shutter speed to catch them before they retreat into their funnel.
Identified: 2026-07-06T20:09:37.170407