Cobweb Spiders vs Common Kidney-Vetch

Parasteatoda tepidariorum compared with Anthyllis vulneraria

Key Differences

Cobweb Spiders is Least Concern while Common Kidney-Vetch is Vulnerable.

Taxonomic Classification

Rank	Cobweb Spiders	Common Kidney-Vetch
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Magnoliophyta (Flowering Plants)
Class	Arachnida (Arachnids)	Magnoliopsida (Dicots)
Order	Araneae (Araneae)	Fabales (Legumes & Allies)
Family	Theridiidae	Fabaceae
Genus	Parasteatoda	Anthyllis
Species	Parasteatoda tepidariorum	Anthyllis vulneraria

Conservation Status

Cobweb Spiders

LC — Least Concern

Common Kidney-Vetch

VU — Vulnerable

Physical Characteristics

Attribute	Cobweb Spiders	Common Kidney-Vetch
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

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).

Common Kidney-Vetch

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, temperate broadleaf and mixed forests, and temperate coniferous forests, among 6 distinct biome types spanning the Indomalayan and Oceanian and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (Libya), Asia (Japan), Europe (9 countries), North America (Canada, United States), and Oceania and the Pacific (Australia). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Common Kidney-Vetch

Common Kidney-Vetch (<em>Anthyllis vulneraria</em>) is a flowering plant in the legume family Fabaceae, assessed as Vulnerable on the IUCN Red List due to habitat degradation and agricultural intensification across parts of its range. It is widely distributed across Africa (Libya), Asia (Japan), Europe (nine countries), North America (Canada and the United States), and Oceania (Australia), occupying six distinct biome types and occurring within the Indomalayan and Oceanian biogeographic realms. The species typically grows in dry, calcareous grasslands, coastal cliffs, sand dunes, and rocky slopes, often favoring nutrient-poor soils. It is an important larval food plant for certain butterfly species, particularly the Small Blue butterfly in Europe, and contributes to soil fertility through nitrogen fixation via root nodules. Its cheerful yellow, orange, or red flower heads make it a recognizable component of chalk and limestone grassland communities. Biological traits of this species remain poorly documented in the scientific literature.