Psilochorus spp.

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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.