Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar
Upcoming Events

Discussion of 2018 gathering

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Photos of insects and people from the 2011 gathering in Iowa

Photos from the 2010 Workshop in Grinnell, Iowa

Photos from the 2009 gathering in Washington

TaxonomyBrowse
Info
ImagesLinksBooksData

Genus Pholcus

My Office Spider - Pholcus phalangioides cellar spider - Pholcus phalangioides - male Cellar Spider? - Pholcus manueli Pholcus phalangioides - Longbodied Cellar Spider - Pholcus phalangioides Female Pholcus phalangioides with Eggs? - Pholcus manueli - female Cellar Spider? - Pholcus opilionoides Spider - Pholcus opilionoides Pholcus phalangioides? - Pholcus phalangioides - female
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Chelicerata (Chelicerates)
Class Arachnida (Arachnids)
Order Araneae (Spiders)
Infraorder Araneomorphae (True Spiders)
No Taxon (Haplogynes)
Family Pholcidae (Cellar Spiders)
Genus Pholcus
Synonyms and other taxonomic changes
Explanation of Names
See chapter 73 in SoNA(1) for an interesting explanation of the name Pholcus. In summary, Walckenaer's intended meaning was likely "squint-eyed," because of how the eyes of the type species are arranged in triangular groups slightly directed away from one another; viewed from some angles, they can appear squint-eyed.
Numbers
13 described species in BugGuide's range, and possibly additional undescribed ones; note that the recently(?) introduced P. opilionoides is included in this count. Also see remarks section for more.
Size
Endemic species:
The kingi species group - 4-5.5 mm

Introduced species:
P. manueli - 4.5-5mm
P. opilionoides - 3-5.5mm
Identification
The endemic (native) species all have a partly divided dark medial mark on the carapace and a grayish-yellow abdomen lacking pattern, although a few are described as having some indistinct internal marks visible through the cuticle. Based on their general descriptions, those 10 endemic Pholcus species sound too similar to identify by their habitus alone, at least until we have images of each one for reference. The unique characters of their genitalia are going to be key to identification, as is ultimately true for all spiders.

It will be rare for BugGuide to get submissions of any of the endemic Pholcus, so it will mostly only be the three (so far) introduced/non-native species that we will see and need to differentiate, thus here is a cheat sheet pertaining to those three in particular:

Pholcus manueli has two dark, vertical stripes on the clypeus (the space between the bottom row of eyes and the beginning of the chelicerae), while P. phalangioides & P. opilionoides do not. The dark medial mark on the carapace of P. manueli is more distinctly divided than the medial mark on P. phalangioides. And P. opilionoides can be separated from the others by the dark marks on the lateral border of their carapace. P. phalangioides also gets bigger than the other two species, at least twice as large in some cases.

    P. manueli     vs.       P. phalangioides       vs.       P. opilionoides
          

In addition, below is a (potentially growing) written list of some traits of each species that may be unique and that may help us separate them visually in the future.

Endemic species (known as the P. kingi species group):
P. cheaha -
P. choctaw - adult females can be distinguished from others in this group by their epigynum that has dark lines converging posteriorly, e.g... \ /
P. dade -
P. dixie -
P. jusahi -
P. kingi -
P. koasati -
P. lanieri - male abdomen with many indistinct darker spots dorsally and laterally, genital area with pair of brown marks.
P. muralicola - significantly smaller than the other endemics.
P. reevesi -

Introduced species:
P. manueli - has two dark, vertical marks on the clypeus (as far as we know, no other species in our range has that feature).
P. opilionoides - distinguished from others by having dark marks on the lateral portions of the carapace; the dark medial marks on the carapace are also more narrow than on the other species.
P. phalangioides - the largest species of the whole group.
Range
Endemic species:
P. cheaha - only known from two localities in Alabama and Tennessee.(2)
P. choctaw - only known from Madison County, Alabama.(2)
P. dade - only known from northwestern Georgia.(2)
P. dixie - only known from Alabama and Tennessee.(2)
P. jusahi - only known from type locality in North Carolina.(2)
P. kingi - only known from Tennessee.(2)
P. koasati - only known from northern Alabama.(2)
P. lanieri - only known from the type locality in northwestern Georgia.(2)
P. muralicola - only known from Missouri and Kansas, though possibly extinct at its type locality: Univ. of Kansas Natural History Reservation. (B. Cutler & H. Guarisco, pers. comm., May 2010 in (2)).(3)
P. reevesi - only known from the type locality in northwestern Georgia.(2)

Introduced species:
P. manueli - introduced synanthrope; midwestern & northeastern United States (specific localities in published literature include IL, KS, ME, MN, NJ, OH, PA.(4)(5)(2)
P. opilionoides - sparingly introduced in North America where distribution is largely unknown (ChH), see related conversation here; also Europe to Azerbaijan.
P. phalangioides - introduced synanthrope; cosmopolitan & widespread worldwide.
Habitat
Most of the endemic species have been collected in and around caves, under rocks, the forest shrub layer, some even from man-made structures.(2) One of those native species, P. muralicola, is probably widespread but in very difficult collecting environment, deep limestone cracks (pers. comm. Bruce Cutler 2011).
The introduced species are synanthropic; they occur in and around buildings and other disturbed habitats.
Remarks
One specimen submitted from Kansas is unique from any other Pholcus we have seen on BugGuide (and/or in North America?) so far:

"The pattern is indeed unusual, and what immediately comes to mind is Pholcus crypticolens. This species seems to be widely distributed in Eastern Asia (Japan, China, Korea, eastern Russia), but I am not sure if the mainland records of P. crypticolens are actually P. spilis, a very similar (and closely related) species currently known from several places in China. In any case, the distribution seems to be affected by humans, and this makes it slightly less surprising to find it in the USA." pers. comm. Dr. Bernhard A. Huber, Alexander Koenig Zoological Research Museum, November 2009 to Andrew Williams.
See Also
Other pholcid genera with cylindrical or elongated oval abdomens: Smeringopus, Holocnemus
Works Cited
1.Spiders of North America: An Identification Manual
D. Ubick, P. Paquin, P.E. Cushing and V. Roth (eds). 2005. American Arachnological Society.
2.Revision and cladistic analysis of Pholcus and closely related taxa (Araneae, Pholcidae)
Bernhard A. Huber. 2011. Bonner zoologische Monographien 58: 1-509.
3.A new pholcid spider from Northeastern Kansas (Arachnida: Araneida)
O. Eugene Maughan & Henry S. Fitch. 1976. Journal of the Kansas Entomological Society 49: 304-312.
4.The identity of the small, widespread, synanthropic Pholcus (Araneae, Pholcidae) species in the northeastern United States
Bruce Cutler. 2007. Transactions of the Kansas Academy of Science 110(1): 129-131.
5.New American spiders
Willis J. Gertsch. 1937. American Museum Novitates 936: 1-7.