Evolution of cave living in Hawaiian Schrankia (Lepidoptera: Noctuidae) with description of a remarkable new cave species

Authors

  • MATTHEW J. MEDEIROS,

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    1. Department of Integrative Biology, University of California, 3060 Valley Life Sciences Building, Berkeley, California 94720, USA
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  • DON DAVIS,

    1. Department of Entomology, Smithsonian Institution, National Museum of Natural History, 10th & Constitution NW, Washington, District of Columbia 20560, USA
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  • FRANCIS G. HOWARTH,

    1. Department of Natural Sciences, Bishop Museum, 1525 Bernice Street, Honolulu, Hawaii 96817, USA
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  • ROSEMARY GILLESPIE

    1. Department of Environmental Science, Policy & Management, Division of Organisms and Environment, 137 Mulford Hall MC 3114, University of California, Berkeley, California 94720, USA
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*E-mail: m_j_m@berkeley.edu

Abstract

Although temperate cave-adapted fauna may evolve as a result of climatic change, tropical cave dwellers probably colonize caves through adaptive shifts to exploit new resources. The founding populations may have traits that make colonization of underground spaces even more likely. To investigate the process of cave adaptation and the number of times that flightlessness has evolved in a group of reportedly flightless Hawaiian cave moths, we tested the flight ability of 54 Schrankia individuals from seven caves on two islands. Several caves on one island were sampled because separate caves could have been colonized by underground connections after flightlessness had already evolved. A phylogeny based on approximately 1500 bp of mtDNA and nDNA showed that Schrankia howarthi sp. nov. invaded caves on two islands, Maui and Hawaii. Cave-adapted adults are not consistently flightless but instead are polymorphic for flight ability. Although the new species appears well suited to underground living, some individuals were found living above ground as well. These individuals, which are capable of flight, suggest that this normally cave-limited species is able to colonize other, geographically separated caves via above-ground dispersal. This is the first example of an apparently cave-adapted species that occurs in caves on two separate Hawaiian islands. A revision of the other Hawaiian Schrankia is presented, revealing that Schrankia simplex, Schrankia oxygramma, Schrankia sarothrura, and Schrankia arrhecta are all junior synonyms of Schrankia altivolans. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156, 114–139.

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