Cobweb spider vs Common Flat-body

Enoplognatha thoracica compared with Agonopterix heracliana

Key Differences

• Cobweb spider is Vulnerable while Common Flat-body is Least Concern.

Taxonomic Classification

Rank	Cobweb spider	Common Flat-body
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (Arthropods)	Arthropoda (Arthropods)
Class	Arachnida (Arachnids)	Insecta (Insects)
Order	Araneae (Araneae)	Lepidoptera (Butterflies & Moths)
Family	Theridiidae	Depressariidae
Genus	Enoplognatha	Agonopterix
Species	Enoplognatha thoracica	Agonopterix heracliana

Evolutionary Relationship

Cobweb spider and Common Flat-body share a common ancestor at the Phylum level: Arthropoda. (Arthropods)

Conservation Status

Cobweb spider

VU — Vulnerable

Common Flat-body

LC — Least Concern

Physical Characteristics

Attribute	Cobweb spider	Common Flat-body
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Cobweb spider

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Found across Europe (4 countries) and North America (Canada, United States). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Flat-body

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

Cobweb spider

Enoplognatha thoracica is a slender cobweb spider in the family Theridiidae, a widespread group of three-dimensional web-building spiders found across the temperate regions of Europe and North America. This small spider, typically measuring 3–5 millimeters in body length, constructs irregular, tangled cobwebs in low vegetation, hedgerows, meadow margins, and scrubby habitats where it captures small flying and crawling arthropods. The body is pale yellowish-brown to creamy white with darker markings on the abdomen, and the legs are long and slender relative to body size, adapted for navigating the three-dimensional structure of its web. Like other theridiids, Enoplognatha thoracica uses a gum-foot trap technique in which sticky vertical threads attached to the substrate at their lower ends snap insects upward when disturbed, immobilizing prey effectively. The species occupies a range spanning much of Europe eastward into temperate Asia and has established populations in parts of North America, likely through accidental human-mediated dispersal. Females produce egg sacs that are guarded within the web until hatching. The species is associated with disturbed and edge habitats and tolerates moderate agricultural landscapes. It is classified as Vulnerable by some assessments, reflecting localized population pressures from habitat loss and intensification of land use in parts of its range, though other evaluations consider it more broadly secure.

Common Flat-body

<em>Agonopterix heracliana</em> is a moth belonging to the family Depressariidae within the order Lepidoptera. Commonly known as the common flat-body, this species is named for the flattened resting posture characteristic of the genus Agonopterix. The species is classified as Least Concern on the IUCN Red List, with no indication of significant population decline. <em>Agonopterix heracliana</em> is distributed across northwestern Europe, with documented occurrences in Belgium, Denmark, Norway, and Sweden. Larvae of this species are typically associated with plants in the family Apiaceae, particularly hogweed (Heracleum sphondylium) and related umbellifers, upon which they feed while sheltering in rolled or folded leaves. Adults are typically brownish with subtle markings and are active from late summer through winter and early spring, overwintering as adults — an unusual life history trait among moths. The species inhabits hedgerows, woodland margins, and meadows where its host plants are abundant. Biological traits of this species remain poorly documented in the scientific literature.

Shared Countries

Both species can be found in 4 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden