cobweb spiders vs Common Roller

Steatoda grossa compared with Ancylis badiana

Taxonomic Classification

Rank	cobweb spiders	Common Roller
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (Arthropods)	Arthropoda (Arthropods)
Class	Arachnida (Arachnids)	Insecta (Insects)
Order	Araneae (Araneae)	Lepidoptera (Butterflies & Moths)
Family	Theridiidae	Tortricidae
Genus	Steatoda	Ancylis
Species	Steatoda grossa	Ancylis badiana

Evolutionary Relationship

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

View Phylum: Arthropoda

Conservation Status

cobweb spiders

LC — Least Concern

Common Roller

LC — Least Concern

Physical Characteristics

Attribute	cobweb spiders	Common Roller
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).

Common Roller

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

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.

Common Roller

<em>Ancylis badiana</em>, the common roller, is a small moth in the family Tortricidae, order Lepidoptera. It is distributed across northwestern Europe, with documented records from Belgium, Denmark, Norway, and Sweden, typically inhabiting woodland margins, hedgerows, scrubland, and areas where its larval host plants are abundant. The species is assessed as Least Concern on the IUCN Red List. Tortricid moths in the genus Ancylis are commonly known as "rollers" or "leafrollers" because their larvae typically roll or fold leaves of host plants to create sheltered feeding structures. <em>Ancylis badiana</em> larvae feed on the foliage of various herbaceous plants, particularly species in the pea family (Fabaceae). Adults are small moths with intricately patterned wings that provide camouflage against bark and plant material. Adult moths are primarily nocturnal and are attracted to light, while larvae are cryptic within their leaf shelters. Biological traits such as lifespan, body measurements, and detailed diet host range remain poorly documented beyond general family-level characteristics. The species typically completes one to two generations per year in temperate European climates, overwintering as pupae. It is considered a minor component of invertebrate biodiversity in European lowland habitats.