cobweb spiders vs Mexican Agouti

Steatoda grossa compared with Dasyprocta mexicana

Key Differences

• cobweb spiders is Least Concern while Mexican Agouti is Critically Endangered.

Taxonomic Classification

Rank	cobweb spiders	Mexican Agouti
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (Arthropods)	Chordata (Chordates)
Class	Arachnida (Arachnids)	Mammalia (Mammals)
Order	Araneae (Araneae)	Rodentia (Rodents)
Family	Theridiidae	Dasyproctidae
Genus	Steatoda	Dasyprocta
Species	Steatoda grossa	Dasyprocta mexicana

Evolutionary Relationship

cobweb spiders and Mexican Agouti share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

cobweb spiders

LC — Least Concern

Mexican Agouti

CR — Critically Endangered

Physical Characteristics

Attribute	cobweb spiders	Mexican Agouti
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), Europe (29 countries), North America (Canada, United States), and South America (Ecuador).

Mexican Agouti

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical coniferous forests, among 5 distinct biome types within the Neotropic biogeographic realm.

Range

Found in Cuba. Currently classified as Critically Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

cobweb spiders

The false black widow (Steatoda grossa) is a cosmopolitan cobweb spider in the family Theridiidae, often mistaken for the true black widow due to its similarly dark, globose abdomen, though it lacks the red hourglass marking. Females reach 6–10 millimeters in body length and display a deep purplish-brown to nearly black coloration with faint pale markings on the dorsal abdomen. Originally native to western Europe, Steatoda grossa has spread globally through human commerce, establishing populations in Australia, New Zealand, North America, and other regions where it thrives in human structures including homes, sheds, and outbuildings. The spider constructs a persistent, tangled cobweb in sheltered corners and recesses, where it captures woodlice, ants, beetles, and other arthropods—notably targeting invertebrates that many other spiders avoid. The venom of S. grossa causes steatodism, a syndrome of localized pain, sweating, and systemic discomfort that is rarely serious but can cause significant distress. Interestingly, the antivenin produced for Latrodectus (true widow) spider bites has been shown to effectively treat Steatoda envenomations, underscoring the phylogenetic relatedness of these genera. Females produce several egg sacs during a season, each containing dozens of eggs wrapped in distinctive silken cocoons. The species is classified as Least Concern given its expanding global distribution facilitated by human activity.