Common Trashline Orb-Weaver
Cyclosa conica
Araneidae (Orb-Weavers), Order Araneae. Key family characteristics include the construction of vertical, spiral orb webs and poor vision supplemented by high sensitivity to web vibrations.
Physical Description
The spider has a distinctively elongated, triangular abdomen that extends backward into a prominent posterior tubercle or tail-like projection, giving it a very unusual silhouette that resembles a piece of debris.
Size Estimate
Body length is typically around 5 to 8 millimeters for females, with males being noticeably smaller. The overall leg span is roughly 15 to 20 millimeters.
Coloration & Markings
Characterized by mottled shades of silver, white, brown, and dark grey, creating a highly effective camouflage pattern that mimics bits of bark, lichen, or detritus.
Web Type
Builds a classic vertical orb web featuring a prominent vertical band of debris, prey remains, and silk called a trashline or stabilimentum, right through the center where the spider rests.
Eye Arrangement
Consists of eight small eyes arranged in two distinct rows typical of orb-weavers, with the lateral eyes often paired and the median eyes set on a slight tubercle.
Leg Characteristics
Legs are relatively slender, banded with dark and light rings, and are typically held tightly pulled in close to the elongated body while resting on the trashline.
Venom & Safety Information
Venom Information
Possesses mild venom used exclusively to immobilize small insect prey. It holds no medical significance for humans.
Medical Significance
Completely harmless to humans. Their mouthparts are generally too small to pierce human skin, and bites result in no systemic effects.
Safety Recommendations
No special safety measures are required as these spiders are entirely harmless. If found on patio furniture or gear, they can be gently relocated using a piece of paper or a cup.
Habitat & Behavior
Habitat & Range
Found across the Holarctic region, including North America, Europe, and parts of Asia. Prefers wooded areas, forest edges, gardens, and shrublands, often building webs between branches or on outdoor structures.
Behavior & Temperament
A sedentary, passive web-builder that spends most of its time motionless in the center of its web. Highly cryptic and relies on camouflage rather than aggression, dropping from the web if disturbed.
Diet & Prey
Feeds on small flying insects such as mosquitoes, midges, and small flies captured in its vertical orb web.
Seasonal Activity
Most active during the warm spring and summer months, with mature adults frequently observed from mid-summer through early autumn.
Description
The Common Trashline Orb-Weaver is a master of disguise in the spider world. Hanging motionless amidst a vertical line of debris in its orb web, it completely confounds predators by looking like a discarded bit of trash or bird droppings rather than a juicy meal. This clever evolutionary strategy makes it a fascinating subject for backyard naturalists.
Key Features
The most diagnostic feature is the elongated, pointed abdomen with a posterior tail-like projection, combined with the signature vertical trashline built directly into the center of its orb web.
Similar Species
Other members of the genus Cyclosa, such as Cyclosa turbinata, which have similar body shapes but may vary slightly in the specific contours of the abdominal tubercles and geographic distribution.
Life Cycle
Overwinters as an egg inside a protected silk cocoon attached to twigs or bark. Spiderlings emerge in spring, grow through multiple molts, and reach maturity by mid-summer.
Ecological Importance
Serves as an effective natural controller of small flying insect populations and contributes to the biodiversity of woodland and garden ecosystems.
Conservation Status
Not evaluated by the IUCN, but populations are widespread, stable, and common throughout their native range.
Interesting Facts
Cyclosa species are famous for building decoys of themselves out of debris along the trashline to distract visual predators like wasps and birds from the actual spider.
Photography Tips
Use a macro lens to capture the fine details of the abdominal shape and coloration. Early morning lighting often reveals dew on the web, highlighting the intricate trashline structure.
Identified: 2026-08-02T15:27:04.493693