Banksula melones
Encyclopedia
Banksula melones is a species of harvestman in family Phalangodidae
Phalangodidae
The Phalangodidae are a family of harvestmen with about 20 genera and more than 100 described species, distributed in the Holarctic Region.It is not to be confused with the harvestman family Phalangiidae, which is in the suborder Eupnoi.-Name:...

. It is endemic to caves along the Stanislaus River
Stanislaus River
The Stanislaus River in California is one of the largest tributaries of the San Joaquin River. The river is long and has north, middle and south forks...

 of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

, USA.

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
Springtail
Springtails form the largest of the three lineages of modern hexapods that are no longer considered insects...

s over booklice
Psocoptera
Psocoptera are an order of insects that are commonly known as booklice, barklice or barkflies. They first appeared in the Permian period, 295–248 million years ago. They are often regarded as the most primitive of the hemipteroids. Their name originates from the Greek word psokos meaning...

.

Conservation

In the late 1970s, the caves of the region were threatened by the construction of the New Melones Dam
New Melones Dam
New Melones Dam is an earth and rock filled dam across the Stanislaus River creating New Melones Lake. Situated between Calaveras and Tuolumne County, California in the Sierra Nevada foothills near Jamestown, the dam was completed in 1979 replacing the old Melones Dam.-Background:The dam was...

. 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.

Further reading

(1978). Final Report on the New Melones Cave Harvestman Transplant. PDF & (2002). The harvestman family Phalangodidae 4. A review of the genus Banksula (Opiliones, Laniatores). The Journal of Arachnology 30: 435-451. PDF
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