''Banksula melones'' is a species of

harvestman The Opiliones (formerly Phalangida) are an order of arachnids colloquially known as harvestmen, harvesters, harvest spiders, or daddy longlegs. , over 6,650 species of harvestmen have been discovered worldwide, although the total number of ext ...

in family Phalangodidae. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

to caves along the Stanislaus River of

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

, United States. This, with a body size of only slightly more than 2 mm, minute harvestman lives only in caves. Its body is colored yellowish-orange, with white to yellowish white appendages. It appears in the same caves as '' Banksula grahami'', which is slightly smaller and has no well-developed eyes. In fact, ''B. melones'' has the best eyes in the whole genus, except for ''B. incredula'', which is the only species that does not inhabit caves. ''B. melones'' has been occasionally found near cave openings. When disturbed, they tend to remain motionless for up to several minutes. They can probably live for several years, which is quite long for a harvestman, with molts occurring only every several months. They have been shown to survive without food for up to 43 days (Rudolph, 1979). They prey on very small arthropods, preferring

springtail Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called En ...

s over

booklice Psocoptera are a paraphyletic group of insects that are commonly known as booklice, barklice or barkflies. The name Psocoptera has been replaced with Psocodea in recent literature, with the inclusion of the former order Phthiraptera into Psocodea ...

Conservation

In the late 1970s, the caves of the region were threatened by the construction of the

New Melones Dam New Melones Dam is an earth and rock filled embankment dam on the Stanislaus River, about west of Jamestown, California, United States, on the border of Calaveras County and Tuolumne County. The water impounded by the dam forms New Melones ...

. ''B. melones'', ''B. grahami'' and about 30 other cave-dwelling species were therefore transplanted from McLean's Cave to an abandoned mine shaft, where the ''Banksula'' species reproduced well at first. However, ten years later, no ''B. grahami'' was found, while more than 50 individuals of ''B. melones'' were counted. Again ten years later, in 1996, only six individuals were left. However, the species was since found in a number of nearby caves.

References

* (1974). Phalangodidae from caves in the Sierra Nevada (California) with a redescription of the type genus (Opiliones: Phalangodidae). ''Occasional Papers of the California Academy of Sciences'' 108: 8 * (1979). Final report on the status of the Melones cave harvestman in the Stanislaus River drainage. Contract #14-16-0009-79-009, U. S. Fish and Wildlife Service, Washington, D.C. * & : Melones cave harvestman
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Conservation

References

Further reading