Uloborus diversus

Marx, 1898

hackled orb-weaver, featherlegged orb-weaver

Uloborus diversus is a -weaving in the Uloboridae. It inhabits desert regions of the southwestern United States and Mexico. The is one of few North spiders that lack glands, instead subduing through constriction. It has become an important model organism for studying the evolution of spidroins (spider silk ) and the neurobiology of orb-web construction . A -level assembly has been completed to support this research.

Uloborus diversus by no rights reserved, uploaded by Jesse Rorabaugh. Used under a CC0 license.Uloborus diversus by no rights reserved, uploaded by Jesse Rorabaugh. Used under a CC0 license.Uloborus diversus by no rights reserved, uploaded by Jesse Rorabaugh. Used under a CC0 license.

Pronunciation

How to pronounce Uloborus diversus: /ˈjuː.ləˌbɔː.ɹəs daɪˈvɜː.səs/

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Identification

Distinguished from other -weaving by the presence of a and ( production system) versus the sticky, glue-studded silk of orb-weavers. Within Uloboridae, U. diversus is separable from by its desert distribution and typical coloration with longitudinal abdominal mottling; however, considerable phenotypic variability has led to many junior synonyms. The reduced, horizontal orb web with possible linear or auxiliary spiral differs from the triangular sector webs of Hyptiotes. Examination of male and female required for definitive identification.

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Habitat

Desert regions of the southwestern United States and Mexico. Constructed webs have been observed in greenhouses, at culvert openings, and in various outdoor situations suggesting adaptability to human-modified environments within arid zones.

Distribution

Southwestern United States and Mexico. Records from Mexico and USA (GBIF).

Life Cycle

Females construct small, flattened, papery sacs typically positioned near the periphery of the web; multiple sacs may be arranged in a row. Spiderlings hatch and immediately build webs, but these differ from webs: they possess additional and retain the auxiliary spiral at the hub because hatchlings lack and . After the second , spiderlings develop these structures and transition to "normal" web architecture.

Behavior

Constructs relatively small, horizontal webs that may incorporate a —either as an auxiliary spiral or a linear through the web center. Lacks glands; subdues through extensive wrapping and constriction that compresses softer body parts and may break appendages, potentially causing asphyxiation as silk dries and tightens. Web construction is slow and methodical, with silk drawn through the and "fluffed" using the .

Ecological Role

of small flying ; may incidentally capture larger insects (such as in greenhouse environments) without successful subjugation, potentially interfering with their and feeding.

Human Relevance

Important model for scientific research on (spidroin) evolution and the neurobiology of -web building . Subject of a 2.15-Gbp -level assembly. Non-venomous; harmless to humans.

Similar Taxa

  • Hyptiotes cavatusAlso in Uloboridae and lacks glands, but constructs triangular sector webs rather than complete , and is primarily eastern North in distribution.
  • Uloborus glomosusCongeneric -weaver with similar and web structure, but differs in geographic distribution and specific genitalic characters; males are rarely observed.
  • Argiope spp. -weavers that construct webs with , but use sticky glue-studded rather than hackled silk, and possess glands.
  • Cyclosa spp. -weavers that may incorporate and debris into webs; differ in (sticky, not ) and presence of .

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