cobweb spiders vs Cole's Wattle

Steatoda grossa compared with Acacia colei

Taxonomic Classification

Rank	cobweb spiders	Cole's Wattle
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	Steatoda	Acacia
Species	Steatoda grossa	Acacia colei

Conservation Status

cobweb spiders

LC — Least Concern

Cole's Wattle

LC — Least Concern

Physical Characteristics

Attribute	cobweb spiders	Cole's Wattle
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).

Cole's Wattle

Habitat

Inhabits tropical and subtropical grasslands and savannas within the Afrotropic biogeographic realm.

Range

Distributed across Kenya and Tanzania.

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.

Cole's Wattle

<em>Acacia colei</em>, commonly known as Cole's Wattle, is a tree or shrub in the family Fabaceae, subfamily Mimosoideae. The species is assessed as Least Concern on the IUCN Red List, indicating that it is not currently at elevated risk of extinction. It is documented in Kenya and Tanzania, where it is associated with tropical and subtropical grasslands and savannas within the Afrotropic realm. Like many acacias, <em>Acacia colei</em> is likely adapted to seasonally dry conditions, which are characteristic of the East African savanna ecosystems it inhabits. Members of the genus <em>Acacia</em> often play important ecological roles, providing shade, food, and habitat for a range of animals, and some fix atmospheric nitrogen through symbiotic associations with soil bacteria. Diet, population estimates, and biological measurements including length, weight, and lifespan are not specified in available data for this species. Biological traits of this species remain poorly documented in the scientific literature. Its Least Concern status reflects a relatively stable population in East African savanna landscapes.