Physocyclus

Members of Physocyclus can be distinguished from the more commonly encountered Pholcus phalangioides (Long-bodied Cellar Spider) by their occurrence patterns; Physocyclus appears to replace Pholcus as the typical indoor cellar spider in the southwestern United States. The genus is characterized by morphological features used in phylogenetic analysis, including 54 discrete character states across binary and multistate traits. Species-level identification requires examination of male pedipalp structures and other genitalic characters.

Species occupy diverse environments including indoor spaces, with P. globosus noted as a common indoor spider in the southwestern United States. The globosus group is associated with Mesoamerican and Mexican Mountain biotic components, while the dugesi group occurs in Mesoamerican and Continental Nearctic regions.

Native range includes South America, Asia, Central America, North America, Africa, Australia, Czechia, and Pacific Islands. Mexico harbors the greatest species diversity with numerous endemic species. P. globosus has been introduced to Africa, Czechia, Iran, Sri Lanka, China, Japan, Philippines, Indonesia, Australia, and Pacific islands.

Observations indicate adult males may wander in search of mates during fall, as documented in New Mexico. Activity likely extends into unseasonably warm late autumn periods in temperate regions.

Web construction behavior differs between life stages and sexes. Early juveniles and adult males construct webs primarily for shelter and lack gumfoot threads. Adult females build prey-capture webs with gumfoot threads that serve as defensive retreats when disturbed. All instars possess piriform spigots capable of producing gumfoot threads, indicating the behavioral difference is not morphologically constrained. Egg sacs are produced by mated females, with spiderlings potentially overwintering within protective silk enclosures.

Adult females construct specialized webs with gumfoot threads used as defensive retreats when disturbed. Early juveniles and adult males exhibit different web architecture suited to shelter rather than prey capture. Adult males have been observed wandering in search of females, sometimes congregating near female webs.

Indoor populations contribute to arthropod pest control, as noted in human dwellings. The genus occupies ecological niches similar to Pholcus in building interiors.

P. globosus serves as a common indoor spider in the southwestern United States, replacing Pholcus phalangioides in this ecological role. Observations suggest these spiders are tolerated or encouraged indoors for pest control of flies and other insects. The genus has been subject to taxonomic research including phylogenetic reanalysis and chromosomal studies.

• Pholcus phalangioidesLong-bodied Cellar Spider; Physocyclus replaces this species as the typical indoor cellar spider in the southwestern United States, though both occupy similar ecological niches in buildings.

• Pholcidae
• cellar spiders
• Mexico
• introduced species
• indoor spiders
• phylogenetics
• cytogenetics
• web architecture
• Araneomorphae
• Haplogynae

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Bug Eric: ArachNovember?
• A reanalysis of the morphological phylogeny of the spider genus Physocyclus Simon (Araneae: Pholcidae) with the description of a new species and description of the female of Physocyclus paredesi Valdez-Mondragón from Mexico
• The Absence of Gumfoot Threads in Webs of Early Juveniles and Adult Males ofPhysocyclus globosus(Pholcidae) is not Associated with Spigot Morphology
• CHROMOSOMES OF CROSSOPRIZA LYONI (BLACKWALL 1867), INTRAINDIVIDUAL NUMERICAL CHROMOSOME VARIATION IN PHYSOCYCLUS GLOBOSUS (TACZANOWSKI 1874), AND THE DISTRIBUTION PATTERN OF NORs (ARANEOMORPHAE, HAPLOGYNAE, PHOLCIDAE)