Theridiidae - Achaearanea canionis
Size: 1.81 mm (male); 3.06 mm (female)
Group Guild Status
Eutroglophile Predator Uncommon
This small species occurs in the cave only near entrance areas, and shares these areas with the pholcid spiders. They are somewhat less common than the pholcids, and they typically spin their webs among rocky rubble in collapse areas near entrances, or between rocks and the cave floor. One of the two records we have of the ptinid beetle (Niptus ventriculus) in the cave was obtained from a specimen trapped in a web of A. canionis just inside the historic Entrance Sink in the Crinoid Room. A juvenile
pseudoscorpion (likely Dinocheirus [arizonensis?]) was found in the chelicerae of an adult female of this species in her web in the Crinoid Room on May 31, 2012. We currently have no other prey records for this species in the cave. Only a single adult male of the species has been found to date, which was observed in a web with a female on September 24, 2011. The female that accompanied it appeared gravid. This species is a eutroglophile in Kartchner Caverns.
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