Harvestman
Protolophus niger (?)
Crawling at night over a moist area of ground in Ponderosa woodlands at Washington Park, Gila Co., Arizona, USA. 13 June 2015.
Sclerosomatidae -- a Harvestman Family
Harvestmen of several different species are likely to be found patrolling about after dark in ponderosa and sycamore woodlands of Arizona. Most are scavengers feeding on dead or moribund insects. Clearly identified as arachnids on account of their eight legs. However because they doe not produce silk nor venom from their chelicerae (mouthparts) they are not spiders. Although not capable of biting people they are able to release pungent, offensive defense chemicals. Many predacious arthropods and insectivorous invertebrates avoid eating harvestmen, perhaps as a result. When attacked they readily shed a leg or two which continues twitching and distracting attention as the harmless arachnid makes its get-away.
Attached to the anterior of the body of this individual is a bright red mite, probably parasitic and feeding on the blood of the harvestman.