The alpine habitat on Mauna Kea represents one of the most extreme environments in the Hawaiian Islands . Daily temperature fluctuations between 116ºF and 25ºF, winter snow pack, and virtually no plant life suggests lifelessness. However, there are creatures that are specialized to live here.
One of the most interesting Hawaiian endemic insects to have evolved on the volcano summit is the Wekiu bug, Nysius wekiuicola. The Wekiu bug is an insect predator-scavenger that tolerates very cold temperatures and preys exclusively on low-elevation insects deposited near the summit by the wind and immobilized by desiccation and cold. This wingless 'true' bug is restricted to the cinder cones of Mauna Kea above 11,500 ft, and exhibits the most extreme specializations of morphological and behavioral characters in the genus Nysius. The Wekiu bug adult is about .5cm long, and the immatures can be as small as .8mm. They are well camouflaged in the cinder at the summit of Mauna Kea .
The Wekiu bug, and other Mauna Kea endemic species, may be threatened by habitat loss due to telescope facility development and competition from introduced species stressing this fragile ecosystem. The Wekiu bug is a candidate for listing under the Endangered Species Act.