Diptera (Hexapoda) diversity in the Shivapuri Mountain Range, Nepal-a rather unexpected Oriental fauna above 1,800 m

Abstract

The Diptera fauna of a small area in Samundradevi, north of Kathmandu, at 1,890 m, was sampled during an expedition, resulting in records of 54 families, of which 176 genera could be recognized. These are the first records for Nepal of 12 fly families—Anisopodidae, Diadocidiidae, Neriidae, Lonchaeidae, Platystomatidae, Piophilidae, Strongylophthalmidae, Diopsidae, Anthomyzidae, Clusiidae, Camillidae, and Stenomicridae—and 86 genera. Our samples from Samundradevi are dominated by Oriental Region elements—while sites with similar altitudes in Nepal or much more to the south in Asia used to have a higher proportion of typically Palearctic components. The possibly complete or nearly complete ice coverage of the Shivapuri Mountain Range along the last glaciation cycle may have entirely wiped out the previous fauna and flora, dominated by Palearctic elements, that would have been replaced more recently by the surrounding Oriental elements.