Uloborus

Uloborus is a genus of cribellate spiders belonging to the family Uloboridae, also known as feather-legged lace weavers. This family is unique among spiders because they lack venom glands entirely. Instead of using venom to subdue their prey, Uloborus spiders rely solely on their cribellum and calamistrum to produce and apply a dense, tangled silk wrapping that suffocates or immobilizes the insect.

Characteristics:

Uloborus spiders are generally small and cryptic, blending in well with their surroundings. Key characteristics include:

• Cribellum and Calamistrum: These are essential for producing and applying their specialized silk. The cribellum is a plate-like structure located in front of the spinnerets, containing thousands of tiny spigots that extrude the fine silk. The calamistrum is a comb-like structure on the fourth pair of legs, used to comb out the silk from the cribellum, giving it a characteristic fuzzy or feathery appearance.
• Absence of Venom Glands: This is the defining feature of the Uloboridae family.
• Web Construction: They build horizontal orb webs or sheet webs, depending on the species. The webs are often decorated with stabilimenta (silken structures of unknown function).
• Camouflage: Many species exhibit excellent camouflage, resembling twigs, bark, or other natural debris.
• Diet: Primarily insects that are ensnared in their sticky webs.

Distribution:

Uloborus spiders are found worldwide in a variety of habitats, including forests, grasslands, and gardens.

Taxonomy:

The genus Uloborus is the largest in the Uloboridae family and contains numerous species. The classification of these species is subject to ongoing research and revision.