cobweb spiders vs koala

Steatoda grossa compared with Phascolarctos cinereus

Key Differences

• cobweb spiders is Least Concern while koala is Vulnerable.

Taxonomic Classification

Rank	cobweb spiders	koala
Kingdom same	Animalia (動物)	Animalia (動物)
Phylum	Arthropoda (節足動物)	Chordata (脊索動物)
Class	Arachnida (クモガタ類)	Mammalia (哺乳類)
Order	Araneae (クモ目)	Diprotodontia (カンガルー目)
Family	Theridiidae	Phascolarctidae (Koalas)
Genus	Steatoda	Phascolarctos (Koalas)
Species	Steatoda grossa	Phascolarctos cinereus

Evolutionary Relationship

cobweb spiders and koala share a common ancestor at the Kingdom level: Animalia. (動物)

Conservation Status

cobweb spiders

LC — Least Concern

koala

VU — Vulnerable

Population: ~100.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	cobweb spiders	koala
Diet	—	Herbivore
Average Lifespan	—	15 years
Average Length	—	75 cm
Average Weight	—	10.0 kg

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).

koala

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

Found in Australia. Currently classified as Vulnerable 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.

koala

オーストラリア東部・南東部を代表する有袋類で、体重は最大15kgに達し、低カロリーのユーカリの葉食から得るエネルギーを節約するために1日最大22時間を睡眠に費やす。他の哺乳類の多くを死に至らしめる有毒なユーカリ成分を処理するために高度に特化しており、解毒に特別に適応した腸内微生物叢を持つ。クラミジア感染症、生息地の伐採、気候変動により個体数が激減し、2022年に絶滅危惧種に指定された。