Filmy Dome Spider
Neriene radiata
Linyphiidae (Sheet-web Spiders), Order Araneae
Physical Description
A small, delicate spider with an elongated cephalothorax and a high, somewhat rounded abdomen that often tapers toward the rear. The body has a smooth texture with very fine hairs. Females are larger and more robust than males, which have more slender bodies and enlarged pedipalps.
Size Estimate
The specimen appears to be an adult female with a body length of approximately 4–5 mm. The leg span is typically between 10–15 mm.
Coloration & Markings
The carapace is brown with darker margins. The abdomen features a distinct pattern of white or pale yellow markings against a darker brown or olive background, often resembling a series of chevrons or a 'scalloped' dorsal line. The sides of the abdomen usually have a bright white or yellow lateral stripe.
Web Type
The spider builds a unique two-part structure: a fine, silk 'dome' roughly 10–15 cm in diameter, suspended by a maze of 'tangle' threads above it and sometimes a flat sheet below it. The spider hangs upside down from the underside of the dome's apex.
Eye Arrangement
Like most Linyphiids, it has eight eyes arranged in two rows of four. The eyes are relatively small and equal in size, though not clearly visible in the provided image due to the distance and silk interference.
Leg Characteristics
The legs are long, thin, and translucent yellowish-brown or green. They lack heavy spines but are covered in fine sensory hairs. The legs are typically held in a spread-out posture while the spider clings to the silk dome.
Venom & Safety Information
Venom Information
The venom is a mild neurotoxin designed to immobilize small insects. It is not considered toxic to humans or large pets.
Medical Significance
Harmless. Their fangs are generally too small to penetrate human skin. In the rare event of a bite, symptoms would be limited to minor, localized irritation similar to a pinprick.
Safety Recommendations
No safety precautions are necessary. They are beneficial garden inhabitants. If found indoors, they can be easily moved outside using a cup and paper, though they rarely survive for long without the structural support needed for their domes.
Habitat & Behavior
Habitat & Range
Common across North America, Europe, and Asia (Holarctic distribution). They prefer damp, shaded areas including deciduous forests, shrubbery, tall grasses, and garden plants like the Hosta visible in the image.
Behavior & Temperament
An ambush hunter that waits at the top of its dome. When an insect flies into the tangle threads above, it falls onto the dome; the spider then bites it through the silk. They are very shy and will drop or retreat to the foliage if disturbed.
Diet & Prey
Primary diet consists of small flying insects such as gnats, flies, small moths, and leafhoppers that become entangled in the upper support threads.
Seasonal Activity
Most active from May through September. They typically overwinter as eggs or immatures in leaf litter.
Description
The Filmy Dome Spider is a masterpiece of architectural silk engineering. This tiny architect spends its life suspended upside down beneath a shimmering umbrella of silk. Often found in gardens and woodlands, their webs are especially visible when covered in morning dew, appearing like miniature crystal ballrooms among the leaves.
Key Features
The distinctive dome-shaped web is the primary diagnostic feature. Morphologically, the white scalloped markings on the dark abdomen and the habit of hanging upside down are key identifiers.
Similar Species
Linyphia triangularis (European Hammock Spider) which builds a flat sheet rather than a dome, and Frontinella communis (Bowl and Doily Spider) which builds a web with a bowl-shaped top and a flat 'doily' sheet beneath.
Life Cycle
Females lay eggs in small, white, flattened egg sacs attached to the underside of leaves near the web. Spiderlings emerge and often disperse via ballooning. The typical lifespan is one year, with adults occurring mostly in late spring and summer.
Ecological Importance
Significant for natural pest control in gardens and forests, as they consume large quantities of small flying pests that might otherwise damage foliage.
Conservation Status
Not evaluated by the IUCN, but considered common and stable throughout its range.
Interesting Facts
The dome shape serves a defensive purpose: it makes it difficult for predators (like wasps) to reach the spider from above, while the spider can easily drop through the open bottom if threatened.
Photography Tips
To capture the web, use a dark background and side-lighting (like early morning sun). For the spider itself, focus on the dorsal pattern of the abdomen while it hangs upside down, using a macro lens if possible.
Identified: 2026-06-11T19:54:20.880693