clouded magpie vs cobweb spiders

Abraxas sylvata compared with Steatoda grossa

Key Differences

• clouded magpie is Vulnerable while cobweb spiders is Least Concern.

Taxonomic Classification

Rank	clouded magpie	cobweb spiders
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (Arthropods)	Arthropoda (Arthropods)
Class	Insecta (Insects)	Arachnida (Arachnids)
Order	Lepidoptera (Butterflies & Moths)	Araneae (Araneae)
Family	Geometridae	Theridiidae
Genus	Abraxas	Steatoda
Species	Abraxas sylvata	Steatoda grossa

Evolutionary Relationship

clouded magpie and cobweb spiders share a common ancestor at the Phylum level: Arthropoda. (Arthropods)

Conservation Status

clouded magpie

VU — Vulnerable

cobweb spiders

LC — Least Concern

Physical Characteristics

Attribute	clouded magpie	cobweb spiders
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

clouded magpie

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its 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).

clouded magpie

The clouded magpie (Abraxas sylvata) is a geometrid moth in the family Geometridae found across temperate Europe, extending eastward through Russia to Japan. The adult wingspan measures approximately 32–42 mm, with white wings bearing a distinctive pattern of yellow-orange and dark grey to black spots and patches arranged in rows across the forewing and hindwing, creating a striking patterned appearance resembling the magpie coloring of the related magpie moth Abraxas grossulariata, but with a more yellowish, muted tone and less black — hence 'clouded.' Adults fly in one generation from June to July, resting on leaf surfaces and attending woodland flowers for nectar. The larvae feed on wych elm (Ulmus glabra) and occasionally other Ulmus species in mature deciduous woodland and woodland edges. The clouded magpie has become less common in parts of its European range due to the widespread loss of mature elms from Dutch elm disease, which devastated European elm populations from the 1970s onward. Conservation of this species requires the protection of surviving mature elm trees and management of regrowth elms in woodland ecosystems.

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.

Shared Countries

Both species can be found in 3 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇸🇪 Sweden