Arachnids of North Carolina
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View Sabaconidae Members: NC Records

Sabacon mitchelli Crosby and Bishop, 1924 - No Common Name

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Taxonomy
Order: OPILIONESSuborder: DyspnoiSuperfamily: IschryopsalidoideaFamily: Sabaconidae                                                                                 
Comments: One of 11 species in this genus that occur in North America north of Mexico (Cokendolpher and Lee, 1993; Holmberg and Buckle, 2019). Three species occur in the East and two in North Carolina.
Species Comment: The type locality for this species is Mt. Mitchell (Crosby and Bishop, 1924). A recent molecular phylogeny study (Schönhofer et al., 2013) revealed that this species is much more closely related to Sabacon species in Japan than it is to S. cavicolens, with which it is sympatric. Based on this result, plus other distinct clusterings of species, they suggest that splitting Sabacon into several genera may be warranted.
Identification
Online Description/Photos: BugGuide Google, iNaturalist, Wikipedia, GBIFTechnical Description: Shear (1975)
Comments: Sabacon species are minute Opiliones distinguished by their enlarged, bristly pedipalps (Shear 1975). Mitchelli is light, purplish brown, with yellow shading on the carapace and abdomen above; no patterning is evident. The coxae and trochanters are light brown but the distal leg segments are darker brown. The palpi and chelicerae are medium brown (Shear, 1975). Sabacon cavicolens is also purplish brown to yellowish but is more mottled and has segmental rows of light spots (Shear, 1975). Structural differences are more important, however, than the differences in pattern and coloration.
Total Length: 1.83 mm, male; 2.71 mm, female (Shear, 1975)Adult ID: identifiable by photo
Structural Features: Sabacon mitchelli is much smaller than S. cavicolens (although both are minute). Males of mitchelli lack the knob-like gland on the basal segment of the chelicerae that is present in cavicolens. Females of mitchelli have only the first two abdominal segments sclerotized, whereas all abdominal segments have sclerotized patches in cavicolens (sclerites are also present in male mitchelli) (Shear, 1975).
Distribution in North Carolina
Comments: Appears to be endemic to the North Carolina mountains
County Map: Clicking on a county returns the records for the species in that county.
Adult phenology:
 High Mountains (HM) ≥ 4,000 ft.
 Low Mountains (LM) < 4,000 ft.
 Piedmont (Pd)
 Coastal Plain (CP)

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Habitats and Life History
Habitats: Known only from three sites worldwide, two in Spruce-Fir Forests at over 6,000' in elevation and one in a cove forest below 4,000'
See also Habitat Account for General High Elevation Forests
Observation Methods: Specimens have been found using direct search under logs and stones; sifting of leaf litter and extraction using Berlese funnels is also useful.
Abundance/Frequency: Multiple individuals have been collected at several sites and the population at Mt. Mitchell has been observed on at least two different occasions
Status in North Carolina
Natural Heritage Program Status: [SR]
Natural Heritage Program Ranks: [GNR] [S1S2]
State Protection: Arachnids are not protected under state law, although permits are needed to collect them in State Parks and other public and private nature preserves.
Comments: This species, along Odiellus nubivagus and Microhexura montivaga were first discovered on an October visit made by Crosby and Bishop in 1923 and subsequently described by those authors. Although all three appear to be narrowly distributed and highly specialized on high elevation habitats in the Southern Appalachians, only the Spruce-Fir Moss Spider has received much notice from conservationists. All three, however, are likely to be similarly affected by the impacts of the Balsam Wooly Adelgid, acid precipitation, and global climate change. While the spider has received a great deal of attention as a federally listed Endangered Species, the other two remain some of the most poorly known species in North America. As in the case of the spider, both of these harvestmen would benefit from more intensive surveys, documenting their overall distribution, habitat needs, and population trends.