The Theridiidae – Cobweb Spiders are a family of spiders belonging to the order Araneae. These spiders are known for their small size, characteristic webs, and varied behaviors. Below is a summary of the main characteristics of Theridiidae:
- Webs: Theridiidae spiders construct irregular sheet-shaped webs, often referred to as “tangled webs.” These webs consist of threads woven into a three-dimensional configuration, forming a chaotic structure that traps prey.
- Morphology: Theridiidae spiders generally have a compact, rounded body with slender legs. Their coloration and appearance vary, but many have complex patterns and bright colors that help them camouflage in their environment.
- Feeding behavior: Theridiidae are mainly insect predators. They often hide in their web, waiting for prey to get caught in the threads or come close enough to be captured.
- Life cycle: Theridiidae spiders go through a typical spider life cycle, including the stages of egg, larva, nymph, and adult. Eggs are usually laid in silk cocoons attached to surfaces near the web.
- Habitat: Theridiidae can be found in a variety of habitats, including gardens, meadows, forests, and shrublands. They often build their webs in discreet and sheltered locations.
The best-known species of the family is Latrodectus mactans, the black widow.
List of Theridiidae genera (external link to Araneae)
Genus Steatoda
Steatoda triangulosa – Triangulate Cobweb Spider
| Order | Aranea |
|---|---|
| Family (Aranea) | Theridiidae |
| Genus | Steatoda |
| Species | Triangulosa |
| Identifier | Walckenaer |
| Year identified | 1802 |
| Male size min | 3.5 |
| Male size max | 5 |
| Female size min | 3.5 |
| Female size max | 8.6 |
| Color | Dark brown to reddish-brown |
| Prosoma/Cephalothorax | – |
| Opisthosoma/Abdomen | light geometric markings with white specks on a dark brown to reddish background |
| Legs (Aranea) | banded |
| Spider habitat | House/indoor habitat, Rocks, Trees |
| Web | irregular-shaped web made of sticky silk, sometimes with a retreat. The cocoons, containing 40 to 100 eggs, are spherical and translucent, attached directly to the web and often visible |
| Period start | January |
| Period end | December |
| Range | Europe, Asia, North America, South America |
| Distinctive features |
Steatoda triangulosa, the Triangulate Cobweb Spider, is recognizable by the pattern on its abdomen. It is a cosmopolitan species. A cousin of the black widow… but harmless.
References:
https://www.gbif.org/fr/species/2157242
https://fr.wikipedia.org/wiki/Steatoda_triangulosa
http://www.dipode-vie.net/arachnides/Theridiidae/Steatoda/tr