Cobweb spider vs Common Sun Beetle

Enoplognatha thoracica compared with Amara aenea

Key Differences

• Cobweb spider is Vulnerable while Common Sun Beetle is Least Concern.

Taxonomic Classification

Rank	Cobweb spider	Common Sun 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 aenea

Evolutionary Relationship

Cobweb spider and Common Sun Beetle share a common ancestor at the Phylum level: Arthropoda. (Arthropods)

Conservation Status

Cobweb spider

VU — Vulnerable

Common Sun Beetle

LC — Least Concern

Physical Characteristics

Attribute	Cobweb spider	Common Sun 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 Sun Beetle

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (7 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 Sun Beetle

<em>Amara aenea</em>, the common sun beetle, is a carabid ground beetle in the family Carabidae, order Coleoptera. It is broadly distributed across Europe and has been introduced to North America, typically inhabiting open, sunny habitats such as arable fields, grasslands, sandy heathlands, and disturbed ground with sparse vegetation. Adults are omnivorous, feeding on seeds, small invertebrates, and plant material, and are considered important predators of weed seeds in agricultural systems. <em>Amara aenea</em> is surface-active during warm, dry conditions, typically exhibiting peak activity in late spring and summer. Like many carabid beetles, it is nocturnal and shelters under stones and debris during the day. Larvae develop in the soil, where they also feed on organic matter and small invertebrates. Biological traits including precise adult lifespan, body length measurements, and detailed prey preferences remain poorly documented at the species level. The species is assessed as Least Concern by the IUCN, reflecting its wide distribution, high adaptability to disturbed environments, and no significant known threats to global population status.

Shared Countries

Both species can be found in 6 countries:

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