Physocyclus globosus

Distinguished from the more common long-bodied cellar spider (Pholcus phalangioides) by its short, broad, globose abdomen versus the elongated, cylindrical abdomen of P. phalangioides. The compact body shape and prominent black dorsal stripe are diagnostic. Within its genus, assigned to the globosus species group based on morphological phylogenetic analysis. In the southwestern United States, it appears to replace P. phalangioides as the typical indoor cellar spider.

Small spider with body length approximately 6 mm. Carapace and abdomen short and broad, giving a compact, globose overall appearance. A prominent black line runs longitudinally along the dorsal surface of the carapace, continuing along most of the abdomen. Eight eyes grouped closely together on a raised hump on the anterior face. Coloration generally brown.

Primarily associated with anthropogenic environments including buildings, cellars, and caves. Occupies dark, sheltered corners of ceilings and walls. In natural settings, occurs in caves. Shows preference for warmer climates but has established populations in temperate regions through human-mediated introduction.

Cosmopolitan distribution throughout warmer parts of the world. Native range includes Mesoamerican and Mexican Mountain biotic components. Introduced populations established in Africa (Congo), Europe (Czechia), Asia (Iran, Sri Lanka, China, Japan, Philippines, Indonesia), Australia, Pacific islands, Galápagos Islands, and South America (Brazil, Venezuela). Present in North America.

Active year-round in suitable indoor environments. Observed in autumn in temperate regions when males wander in search of mates. Ballooning behavior for dispersal reported in fall for related species, though not specifically documented for this species.

Development includes early juvenile stages that construct webs lacking gumfoot threads, unlike adult females. Egg sacs produced by females, with spiderlings developing within silk insulation. Intraindividual numerical chromosome variation has been documented.

Constructs irregular, tangled webs in corners of ceilings and walls. Adult males and early juveniles build webs that lack gumfoot threads—sticky trapping lines typical of pholcid webs—despite possessing the morphological structures (spigots) to produce them. This behavioral difference is not explained by spigot morphology. Males wander in search of females in autumn. Females remain in webs, which may contain multiple individuals including males.

Common household spider in tropical and subtropical regions, and increasingly in temperate areas. Considered beneficial as it preys on other arthropods including flies and insects. Frequently encountered in cellars, hence the common name. Non-aggressive and harmless to humans.

• Pholcus phalangioidesLong-bodied cellar spider with elongated, cylindrical abdomen versus the short, globose abdomen of P. globosus; P. globosus replaces P. phalangioides as the typical indoor pholcid in the southwestern United States

• spider
• Pholcidae
• cellar spider
• cosmopolitan
• introduced species
• anthropogenic habitat

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Bug Eric: ArachNovember?
• CHROMOSOMES OF CROSSOPRIZA LYONI (BLACKWALL 1867), INTRAINDIVIDUAL NUMERICAL CHROMOSOME VARIATION IN PHYSOCYCLUS GLOBOSUS (TACZANOWSKI 1874), AND THE DISTRIBUTION PATTERN OF NORs (ARANEOMORPHAE, HAPLOGYNAE, PHOLCIDAE)
• The Absence of Gumfoot Threads in Webs of Early Juveniles and Adult Males ofPhysocyclus globosus(Pholcidae) is not Associated with Spigot Morphology
• 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