Uloborus campestratus
Simon, 1893
Featherlegged Orb-weaver, Hackled Band Orb-weaver
Uloborus campestratus is a small -weaving in the Uloboridae. It is one of five Uloborus in North America, distributed from the United States to Venezuela. Like all uloborids, it lacks glands and subdues through extensive wrapping and constriction rather than venomous bites. The species builds small horizontal orb webs with hackled, non-sticky capture threads produced by its and fluffed using a on its hind legs.
Pronunciation
How to pronounce Uloborus campestratus: /ˌjuː.loʊˈbɔːrəs kæmpˈɛstreɪtəs/
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Identification
Distinguished from other -weavers by (non-sticky, hackled threads) rather than viscid glue droplets. Separated from orb-weavers (Araneidae, Tetragnathidae) by presence of and . Among Uloborus , specific identification requires examination of ; U. campestratus is the only species in the with documented range extending from USA through Central America to Venezuela.
Habitat
Found in diverse outdoor situations including greenhouses, culvert openings, and vegetation. Webs typically constructed in sheltered locations. Specific microhabitat preferences for U. campestratus not documented separately from .
Distribution
Geographic range extends from the United States (southern portions) through Mexico and Central America to Venezuela. Records from Mexico and USA-Venezuela span.
Diet
Feeds on small flying captured in webs. size limited by 's small stature and non-venomous capture method.
Life Cycle
Females construct small, flattened, papery sacs, usually placed near web periphery; multiple sacs may be arranged in a row. Spiderlings hatch without and , building webs with additional and retained auxiliary spiral at hub. After second , spiderlings acquire cribellum and calamistrum, enabling 'normal' web construction.
Behavior
Builds small horizontal webs, often with (thickened zig-zag or linear ). When contacts web, wraps victim extensively in silk — observed to take approximately 10 minutes even for small prey. Constriction of silk binding compresses softer body parts and may break appendages; suspected that drying silk shrinks, tightening around prey until asphyxiation. Web construction slow: each tangled spiral drawn through and 'fluffed' with , requiring hours to complete.
Ecological Role
of small ; contributes to regulation in web-building microhabitats.
Human Relevance
Occasionally found in greenhouses and human-altered environments. Non-venomous and harmless to humans. can incapacitate large like in enclosed exhibits, though cannot consume such oversized .
Similar Taxa
- Hyptiotes spp. (triangle spiders)Also Uloboridae with and , but build triangular sector webs rather than complete , and use web-releasing capture mechanism.
- Araneidae (typical orb-weavers)Build similar webs but use viscid sticky rather than hackled threads; lack and ; possess glands.
- Other Uloborus speciesFour other North (U. glomosus, U. diversus, U. americanus, U. octomaculatus) share featherlegged appearance and web structure; require genital examination for definitive identification.
More Details
Cribellate silk production
Uloborus campestratus produces through a multi-step : the issues fine threads that are combed by the into tangled, woolly strands. This hackled silk snares mechanically without adhesive, representing an evolutionary alternative to the viscid silk of -weavers.
Venom gland absence
All Uloboridae, including U. campestratus, lack glands — unique among North . This anatomical loss correlates with extreme -wrapping and constriction-based subdual.