Bridge Spider, Gray Cross Spider
Larinioides sclopetarius
Araneidae (Orb-Weavers), Order Araneae
Physical Description
A robust orb-weaver with a flattened, oval abdomen and a hairy cephalothorax. The abdomen features a distinct wavy or scalloped pattern on the dorsal side.
Size Estimate
Body length 10-14mm for females, 6-8mm for males. Total leg span regularly reaches 25-35mm. This appears to be an adult female.
Coloration & Markings
Characterized by a high-contrast 'folium' (leaf-like) pattern on the abdomen in shades of gray, white, and dark brown. The pattern is outlined in white or pale gray.
Web Type
Large, symmetrical orb webs constructed near water or artificial lights. They often hide in nearby crevices during the day.
Eye Arrangement
Eight eyes arranged in two rows of four; the median eyes form a trapezoid, typical of the Araneidae family.
Leg Characteristics
Strong, moderately long legs with distinct dark and light banding. They possess small spines and macrosetae for sensory input and prey manipulation.
Venom & Safety Information
Venom Information
Contains neurotoxic proteins specific to insects. Not considered toxic or medically significant to humans.
Medical Significance
Harmless. Bites are rare and usually result in localized redness or mild itching similar to a bee sting. No specialized treatment is required.
Safety Recommendations
No action is needed as they are beneficial. If relocation is desired, use a cup and paper to move the spider to an outdoor railing or fence.
Habitat & Behavior
Habitat & Range
Holarctic distribution (North America and Europe). They are synanthropic, preferring man-made structures like bridges, fences, and steel railings near water.
Behavior & Temperament
Nocturnal hunters that hide in retreats during the day. They are docile and non-aggressive toward humans, preferring to flee or drop on a silk line if disturbed.
Diet & Prey
Generalist insectivores, primarily feeding on flying insects like midges, flies, and moths that are attracted to lights near their webs.
Seasonal Activity
Most active from late spring through autumn. Large populations can sometimes be seen huddled together in overwintering crevices.
Description
A common sight on urban structures, the Bridge Spider is an architectural specialist that thrives on the abundance of insects found near human lighting and water.
Key Features
White-outlined scalloped abdomen pattern, banded legs, and a preference for steel/wood structures over vegetation.
Similar Species
Larinioides cornutus (Furrow Spider) is very similar but prefers vegetation; Araneus diadematus has a distinct white cross pattern.
Life Cycle
Females lay egg sacs in protected crevices in autumn. Spiderlings emerge in spring. They are known for 'ballooning' to new locations using silk threads.
Ecological Importance
Highly effective at urban pest control, consuming thousands of midges and mosquitoes throughout their lifespan.
Conservation Status
Not evaluated by IUCN; however, they are widespread and common with stable populations in urban environments.
Interesting Facts
This species shows a strong preference for steel surfaces, which stay warm and attract prey, making bridges their ideal ecological niche.
Photography Tips
Focus on the dorsal abdomen pattern for ID. Use a flash to highlight the contrast in the folium markings against the gray body.
Identified: 2026-07-12T17:01:16.735578