Grass Spider, Funnel Weaver
Agelenopsis aperta or similar Agelenidae species
Agelenidae (Funnel Web Weavers), Order Araneae. Key family characteristics include long, distinct spinnerets at the rear of the abdomen and a characteristic sheet web that ends in a tubular retreat.
Physical Description
The spider has a relatively elongated body with a tapering, pointed abdomen and a distinct cephalothorax marked by longitudinal stripes. The overall build is athletic and robust, typical of active running spiders.
Size Estimate
Body length is roughly 10-15 mm with a leg span reaching up to 30-40 mm. This specimen appears to be an adult or sub-adult.
Coloration & Markings
Predominantly brown and tan with dark longitudinal stripes running along the carapace (cephalothorax) and lighter, mottled patterns on the dorsal abdomen.
Web Type
Builds a horizontal, non-sticky sheet web made of dense silk that terminates in a funnel-shaped retreat where the spider hides, waiting for prey to land on the sheet.
Eye Arrangement
Eight small eyes arranged in two closely spaced, curved rows across the front of the carapace, typical of funnel weavers.
Leg Characteristics
Long, tapered legs covered in fine hairs and prominent spines used for rapid sprinting across the sheet web. Legs are typically spread wide in an alert posture.
Venom & Safety Information
Venom Information
Contains mild, non-lethal neurotoxic venom primarily specialized for subduing small insect prey quickly.
Medical Significance
Not medically significant. A bite may cause minor, localized pain, redness, or swelling similar to a mosquito bite, but they pose no serious danger to humans.
Safety Recommendations
Seal cracks around windows and doors to prevent indoor entry. If relocation is necessary, gently guide the spider into a cup using a piece of cardstock and release it outdoors.
Habitat & Behavior
Habitat & Range
Found across North America, commonly inhabiting grassy fields, low vegetation, and frequently wandering indoors near window sills, doorframes, and basements.
Behavior & Temperament
Extremely fast and skittish. When disturbed, they dart rapidly into their funnel retreat. They are non-aggressive toward humans and will only bite if firmly trapped against the skin.
Diet & Prey
Primarily feeds on flying and crawling insects such as flies, beetles, grasshoppers, and moths that land on their sheet web.
Seasonal Activity
Most active during late spring, summer, and early autumn, with mature males frequently wandering indoors in search of mates during the fall.
Description
This is a classic grass spider or funnel weaver, easily recognized by its brownish, striped body and the sheet-like web it constructs near structural crevices or vegetation. While their sudden movements can startle homeowners, they are harmless pest controllers that prefer to flee rather than fight.
Key Features
Distinctive longitudinal stripes on the cephalothorax, prominent rear spinnerets, and a horizontal sheet web ending in a tubular funnel retreat.
Similar Species
Often confused with Wolf Spiders (Lycosidae) or the Brown Recluse (Loxosceles reclusa). Unlike wolf spiders, grass spiders have prominent long spinnerets and build sheet webs. Unlike brown recluses, they have prominent stripes on the back and do not possess the violin marking.
Life Cycle
Females construct tough, disc-shaped silk egg sacs in sheltered areas during autumn. Eggs overwinter, and spiderlings hatch in spring to mature by late summer.
Ecological Importance
Acts as an effective natural pest control agent by regulating populations of nuisance insects around homes and gardens.
Conservation Status
Not evaluated by the IUCN, but populations are abundant, secure, and widespread.
Interesting Facts
Grass spiders possess some of the fastest acceleration rates among terrestrial animals when sprinting across their webs to capture prey.
Photography Tips
Use natural indirect lighting to capture the fine striped details on the carapace. Maintain a safe, low angle without disturbing the spider to avoid sending it rushing back into its retreat.
Identified: 2026-08-27T15:01:06.663232