Chestnut Coloured Click Beetle vs Cobweb Spiders

Anostirus castaneus compared with Parasteatoda tepidariorum

Taxonomic Classification

Rank	Chestnut Coloured Click Beetle	Cobweb Spiders
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (Arthropods)	Arthropoda (Arthropods)
Class	Insecta (Insects)	Arachnida (Arachnids)
Order	Coleoptera (Beetles)	Araneae (Araneae)
Family	Elateridae	Theridiidae
Genus	Anostirus	Parasteatoda
Species	Anostirus castaneus	Parasteatoda tepidariorum

Evolutionary Relationship

Chestnut Coloured Click Beetle and Cobweb Spiders share a common ancestor at the Phylum level: Arthropoda. (Arthropods)

Conservation Status

Chestnut Coloured Click Beetle

LC — Least Concern

Cobweb Spiders

LC — Least Concern

Physical Characteristics

Attribute	Chestnut Coloured Click Beetle	Cobweb Spiders
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Chestnut Coloured Click Beetle

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, Sweden, and Switzerland.

Cobweb Spiders

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Africa (South Africa), Asia (Taiwan), Europe (7 countries), North America (Canada, United States), and South America (Colombia).

Chestnut Coloured Click Beetle

The Chestnut Coloured Click Beetle (Anostirus castaneus) is a species in the genus Anostirus. It is currently classified as Least Concern on the IUCN Red List. Typically found in virtually all terrestrial and freshwater habitats.

Cobweb Spiders

The common house spider (Parasteatoda tepidariorum) is one of the most cosmopolitan of all spider species, having followed human civilization to virtually every inhabited corner of the globe. A member of the family Theridiidae, this small to medium-sized spider—females reaching 5–8 millimeters, males somewhat smaller—constructs the characteristic messy, three-dimensional cobwebs in sheltered corners of buildings, under eaves, in cellars, and in other human-modified structures worldwide. Originally native to North and South America, the species has spread through commerce and human transport to Europe, Asia, Africa, and beyond, where it thrives in the stable temperature and prey-rich conditions provided by human habitation. The web design is deceptively effective: irregular sticky threads radiate in all directions from a silk retreat, ensnaring flies, mosquitoes, ants, and other arthropods that blunder into the structure. Females are long-lived—surviving several years—and produce multiple egg sacs containing hundreds of eggs during a lifetime, contributing to the species' population resilience. Parasteatoda tepidariorum has become an important laboratory model organism for arachnid developmental biology, with its genome sequenced to facilitate studies of spider gene expression, venom evolution, and silk production. It is broadly classified as Least Concern given its cosmopolitan distribution and remarkable adaptation to anthropogenic environments.

Shared Countries

Both species can be found in 4 countries:

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