Cobweb Spiders vs common greasewort

Parasteatoda tepidariorum compared with Aneura pinguis

Taxonomic Classification

Rank	Cobweb Spiders	common greasewort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Marchantiophyta (liverwort)
Class	Arachnida (Arachnids)	Jungermanniopsida (Jungermanniopsida)
Order	Araneae (Araneae)	Metzgeriales (Metzgeriales)
Family	Theridiidae	Aneuraceae
Genus	Parasteatoda	Aneura
Species	Parasteatoda tepidariorum	Aneura pinguis

Conservation Status

Cobweb Spiders

LC — Least Concern

common greasewort

LC — Least Concern

Physical Characteristics

Attribute	Cobweb Spiders	common greasewort
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 greasewort

Habitat

Native to Asia and Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Widely distributed across Asia (Taiwan), Europe (6 countries), North America (United States), and South America (Brazil, Colombia).

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 greasewort

<em>Aneura pinguis</em>, commonly known as common greasewort, is a liverwort belonging to the genus Aneura within the family Aneuraceae. This cryptogamic plant inhabits ecosystems across Asia, Europe, and North America, thriving in moist or waterlogged environments. Its range encompasses Taiwan in Asia, six European countries, the United States in North America, and Brazil and Colombia in South America, indicating a broad geographic distribution across multiple continents. Common greasewort is assessed as Least Concern on the IUCN Red List. The species typically forms flat, ribbon-like thalli in damp habitats such as stream banks, wet rocks, and boggy ground. Biological traits of this species remain poorly documented in the scientific literature.

Shared Countries

Both species can be found in 8 countries:

🇧🇪 Belgium 🇨🇴 Colombia 🇩🇰 Denmark 🇳🇴 Norway 🇵🇹 Portugal 🇸🇪 Sweden 🇹🇼 Taiwan 🇺🇸 United States