The cavernicolous fauna of Hawaiian lava tubes, Part VI. Mesoveliidae or water treaders (Heteroptera)

Abstract

This paper is a systematic report and a biological analysis of the Mesoveliidae from Hawaiian caves. Most important is a new species of Speovelia Esaki, S. sp. (Hawaii I.), described from material collected on moist walls in lava tubes. This apparently represents the world's first troglobitic heteropteran. Morphologically, all instars show lack of pigmentation, functionless eyes and prolongation of the appendages and head. Biologically, it is restricted to the dark zone of lava tubes. Notes on its biology are given. It also represents the first known endemic species of the family for the Hawaiian Islands. Another species, Mesovelia amoena Uhler, is troglophilic. This is the first record of this immigrant American species in the Hawaiian Islands. The remaining species in Hawaii, the immigrant M. mulsanti White, has only been found in epigean situations. A key to the species is also presented.