Psilochorus spp.
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adult female, live; note long legs |
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adult male, live; note long legs |
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female genitalia; epigynum |
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female genitalia; epigynum, lateral view |
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male genitalia; palp, lateral view |
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male genitalia; palp, medial view |
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grape size comparison with adult spiders; male (left), female (right) |
Current valid name
Psilochorus papago Gertsch and Davis (family Pholcidae), Psilochorus utahensis Chamberlin (family Pholcidae)
Recognition and diagnostic features
Both species have very long and flimsy legs with globose abdomens. It is extremely difficult to distinguish one species from the other even when examining genitalia.
Related or similar species
Holocnemus pluchei
Spider
Range of body lengths when mature: (P. papago) male: 2.54 ± 0.20 mm, female: 2.46 ± 0.47 mm, (P. utahensis) male: 3.23 ± 0.04 mm, female: 3.77 ± 0.55 mm
Immatures resemble miniature adults.
Egg sac
Because these spiders carry their egg sacs around in their fangs, the sacs will never be deposited in grape bunches.
Distribution
In California: southern California
Elsewhere: southern Arizona, Great Basin area
Native to North America
This species has not been transported or become established outside of its range.
Biology
Makes webs under canopy. Uncommon in grapes overall.
Status in table grapes
Level of Incidence: none
Level of Concern in New Zealand: WPNZ (May 2010) nr, BORIC (Dec 2011) nr (not listed), MAF-BPRA (2002) nr (coding definition)
Level of Concern in Australia: WPAU (2006) nr (coding definition)
Level of Medical importance: none
Common name
None for either species, cellar spiders or daddylonglegs spiders for family
Taxonomic history
Stable for both species.
Selected references
Slowik, J. 2009. A review of the cellar spider genus Psilochorus Simon 1893 in America north of Mexico (Araneae: Pholcidae). Zootaxa 2144: 1-53.
