Malheur Pseudoscorpion

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  • Species Common Name Malheur Pseudoscorpion
  • Species Scientific Name Apochthonius malheuri
  • Federal Listing Status Species of Concern


Special needs

Malheur Cave is a thermal lava tube cave that supports the largest array of cave-adapted species in the Pacific Northwest. It contains a geothermal lake which regulates climate within the cave (making it warmer than outside surface temperatures). Species have adapted to this moist, warm environment, and they also require wood and other materials for substrate. Small mammals and bats bring this material into the cave.

Limiting factors

Malheur pseudoscorpions are endemic to Malheur Cave and therefore highly vulnerable to random or localized disturbance. Potential disturbance from pesticide drift, water diversion, or visitor use could severely impact this species.

Conservation actions

Continue to maintain suitable habitat, especially water quality. Manage recreation to minimize impacts to endemic species.