Stabilimentum
Guides
Argiope
Garden Orbweavers, St Andrew's Cross Spiders, Writing Spiders, Garden Spiders
Argiope is a genus of large, colorful orb-weaving spiders in the family Araneidae. The name derives from Greek, meaning 'silver-faced,' referring to the silvery cephalothorax characteristic of many species. Females are notably larger than males and often display striking abdominal color patterns in yellow, black, and silver. These spiders construct spiral orb webs that frequently include a conspicuous zigzag silk structure called a stabilimentum. The genus has a worldwide distribution, with species found across tropical and temperate regions on every continent except Antarctica.
Argiope argentata
Silver Argiope, Silver Garden Spider, Silver Garden Orbweaver
Argiope argentata is a large, striking orb-weaving spider found from the southern United States through Central and South America to Chile and Argentina. Females are notable for their silvery cephalothorax and distinctive X-shaped stabilimentum in their webs, formed by four zigzag silk bands. The species exhibits extreme sexual dimorphism, with females reaching 12–16 mm body length while males are only 4–5 mm. Unlike many temperate Argiope species that mature in late summer, A. argentata adults may be found year-round in warmer regions, with males maturing as early as February. The spider incorporates UV-reflecting silks into both its body coloration and web decorations, which may function to attract pollinating prey by mimicking floral signals.
Argiope aurantia
yellow garden spider, black and yellow garden spider, golden garden spider, writing spider, zigzag spider, zipper spider, black and yellow argiope, corn spider, Steeler spider, McKinley spider
Argiope aurantia is a large orb-weaving spider recognized by its bold yellow and black abdominal markings and distinctive web architecture. Females construct conspicuous circular webs up to 60 cm in diameter, featuring a dense zigzag band of silk called a stabilimentum at the center. The species exhibits pronounced sexual dimorphism: females reach 19–28 mm in body length with a mass around 752 mg, while males are substantially smaller at 5–9 mm. This spider is common in gardens, meadows, and open habitats across much of North America, where it serves as a significant predator of insects and other small arthropods.
Argiope florida
Florida argiope, Florida garden spider
Argiope florida is a species of orb-weaving spider in the family Araneidae, restricted to the southeastern United States. Like other Argiope species, it constructs spiral orb webs with a conspicuous silk decoration called a stabilimentum. Research on this species has focused on the function of these web decorations and their influence on spider behavior, including fleeing responses and anti-predator strategies.
Argiope trifasciata
banded garden spider, banded orb weaving spider, banded argiope, whitebacked garden spider
A large orb-weaving spider with a nearly cosmopolitan distribution, native to the Americas but now found across six continents. Females construct distinctive spiral orb webs up to 60 cm in diameter, often decorated with zigzag stabilimentum patterns. The species exhibits notable thermoregulatory behavior through strategic web orientation and body positioning. Recent phylogeographic research suggests A. trifasciata may represent a complex of cryptic species rather than a single widespread species.
Cyclosa
Trashline Orbweavers
Cyclosa is a genus of orb-weaver spiders commonly known as trashline orbweavers, first described by Anton Menge in 1866. These spiders are distinguished by their unique web decorations consisting of linear arrangements of prey remains, debris, and sometimes egg sacs arranged vertically through the web center. The name derives from Greek 'to move in a circle,' referencing their spiral web construction. Most species face downward in their webs, though some face upward. The genus contains approximately 178 species distributed worldwide.
Cyclosa conica
Conical Trashline Orbweaver
Cyclosa conica is a small orb-weaving spider known for constructing distinctive vertical webs decorated with debris. Females measure 5.3–7.5 mm in body length, while males are smaller at 3.6–4 mm. The species is recognized by its unique behavior of stringing dead insect bodies and other debris vertically through the center of its web, forming a 'trashline' or stabilimentum. The spider positions itself at the hub of this debris, relying on its cryptic coloration to blend in and avoid detection by predators. When disturbed, it feigns death as a secondary defense.
Mangora
Tuftlegged Orbweaver, Stabilimentum Orb-weaver
Mangora is a genus of small orb-weaving spiders in the family Araneidae, commonly known as tuftlegged orbweavers. These spiders are distinguished by their compact bodies, often with prominent abdominal projections or tubercles, and their distinctive vertical orb webs that frequently feature white silk decorations called stabilimenta. The genus occurs across North America, Europe, and parts of Asia, with species inhabiting diverse habitats from woodlands to grasslands. Mangora spiders are active primarily in late spring and summer, with some species producing multiple generations per year.
Micrathena
spiny orbweavers, spiny orb-weavers
Micrathena is a genus of orb-weaver spiders containing over 100 species, predominantly distributed in Neotropical woodlands. Females are characterized by hardened abdomens bearing prominent spines, which have evolved independently at least eight times and function as anti-predator defenses. These spiders construct vertical orb webs and are diurnally active. The genus originated approximately 25 million years ago and has undergone extensive diversification in Andean cloud forests.
Micrathena sagittata
Arrow-shaped Micrathena, Arrow-shaped Orbweaver
Micrathena sagittata is a small orb-weaving spider in the family Araneidae, recognized by its distinctive arrow-shaped abdomen with prominent spines. Females reach 8-9 mm in body length, while smaller males lack spines entirely. The species constructs circular webs approximately 30 cm in diameter in forest understory vegetation, where it captures flying and jumping insects. It occurs across the eastern United States and Central America, with peak activity from July through September.
Uloborus
Feather-legged Spiders, Featherlegged Orb-weavers, Hackled Band Orb-weavers
Uloborus is a genus of cribellate orb-weaving spiders in the family Uloboridae, comprising approximately 72 described species. These small spiders (3–6 mm body length) are unique among orb-weavers in lacking venom glands entirely, instead relying on constriction and digestive enzymes to subdue prey. They construct small horizontal orb-webs with hackled, non-sticky silk produced by a specialized cribellum organ, often incorporating a stabilimentum—a thickened linear or zigzag silk band at the web hub. The genus is predominantly tropical and subtropical in distribution, with only a few species extending into temperate North America and Europe.
Uloborus campestratus
Featherlegged Orb-weaver, Hackled Band Orb-weaver
Uloborus campestratus is a small cribellate orb-weaving spider in the family Uloboridae. It is one of five Uloborus species in North America, distributed from the United States to Venezuela. Like all uloborids, it lacks venom glands and subdues prey through extensive silk wrapping and constriction rather than venomous bites. The species builds small horizontal orb webs with hackled, non-sticky capture threads produced by its cribellum and fluffed using a calamistrum comb on its hind legs.
Uloborus diversus
hackled orb-weaver, featherlegged orb-weaver
Uloborus diversus is a cribellate orb-weaving spider in the family Uloboridae. It inhabits desert regions of the southwestern United States and Mexico. The species is one of few North American spiders that lack venom glands, instead subduing prey through silk constriction. It has become an important model organism for studying the evolution of spidroins (spider silk proteins) and the neurobiology of orb-web construction behavior. A chromosome-level genome assembly has been completed to support this research.
Uloborus glomosus
Featherlegged Orbweaver
Uloborus glomosus is a small cribellate orb-weaving spider and the only member of its genus recorded in Canada. It belongs to the family Uloboridae, a group distinguished by the absence of venom glands. The species captures prey using hackled, non-sticky silk produced by a specialized spinning organ called the cribellum. Prey is subdued through extensive wrapping and constriction rather than venomous bite.