cobweb spiders vs Common Dart

Steatoda grossa compared with Andronymus caesar

Taxonomic Classification

Rank	cobweb spiders	Common Dart
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	Hesperiidae
Genus	Steatoda	Andronymus
Species	Steatoda grossa	Andronymus caesar

Evolutionary Relationship

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

Conservation Status

cobweb spiders

LC — Least Concern

Common Dart

LC — Least Concern

Physical Characteristics

Attribute	cobweb spiders	Common Dart
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 Dart

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

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 Dart

<em>Andronymus caesar</em>, known as the common dart, is a butterfly belonging to the family Hesperiidae. This species occupies terrestrial and freshwater habitats, though its specific geographic range is not well characterized in current biodiversity databases. Like other members of the genus Andronymus, <em>Andronymus caesar</em> is likely associated with open woodland, savanna, and grassland ecosystems typical of sub-Saharan Africa, where many related hesperiid species are found. Adults typically exhibit rapid, darting flight patterns and are often observed perching on low vegetation or feeding on flower nectar. Larvae of closely related species are generally known to feed on grasses and related monocots, though host plant preferences specific to <em>Andronymus caesar</em> have not been thoroughly detailed in the available scientific literature. The species is assessed as Least Concern, indicating that no significant population declines or major threats have been identified. Biological traits of this species remain poorly documented, and detailed ecological and life history research would contribute substantially to understanding this taxon.