Cobweb spider vs Common harp ground beetle

Enoplognatha thoracica compared with Amara communis

Key Differences

• Cobweb spider is Vulnerable while Common harp ground beetle is Least Concern.

Taxonomic Classification

Rank	Cobweb spider	Common harp ground beetle
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (Arthropods)	Arthropoda (Arthropods)
Class	Arachnida (Arachnids)	Insecta (Insects)
Order	Araneae (Araneae)	Coleoptera (Beetles)
Family	Theridiidae	Carabidae
Genus	Enoplognatha	Amara
Species	Enoplognatha thoracica	Amara communis

Evolutionary Relationship

Cobweb spider and Common harp ground beetle share a common ancestor at the Phylum level: Arthropoda. (Arthropods)

Conservation Status

Cobweb spider

VU — Vulnerable

Common harp ground beetle

LC — Least Concern

Physical Characteristics

Attribute	Cobweb spider	Common harp ground beetle
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 harp ground beetle

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (5 countries) and North America (Canada, United States).

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 harp ground beetle

The common harp ground beetle, <em>Amara communis</em>, is an insect belonging to the order Coleoptera, family Carabidae, the ground beetles. This species is distributed across Europe and North America, indicating a wide Holarctic range. Ground beetles of the genus Amara are typically found in a variety of terrestrial habitats including grasslands, agricultural fields, woodland margins, and disturbed areas. Members of this genus are generally omnivorous or seed-feeding, and some are known to consume weed seeds, giving them potential ecological significance in agroecosystems. <em>Amara communis</em> is assessed as Least Concern on the IUCN Red List, reflecting stable populations across its range. No dietary information has been provided specifically for this species in current records. Biological traits of this species remain poorly documented in the scientific literature.

Shared Countries

Both species can be found in 6 countries:

🇧🇪 Belgium 🇨🇦 Canada 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States