Climbing the Trichoptera Tree : Investigations of Branches and Leaves

Sammanfattning: The Trichoptera (caddisflies) is the largest of the primary aquatic insect orders, currently including more than 13,500 species. With more than 100 species new to science described annually, the known caddisfly diversity is rapidly increasing. In the first four papers of this Thesis, a total of 22 species new to science are described. The first three papers include revisions of the New Caledonian species for the genera Symphitoneuria, Gracilipsodes and Triplectides, with descriptions of 3, 7 and 11 new species, respectively. In these papers I strengthen our image of New Caledonia as a biodiversity hotspot. The fourth paper describes a new genus and species from Madagascar, another biodiversity hotspot. These four papers all deal with species and genera of the family Leptoceridae, which ranks among the three largest families within Trichoptera. The family comprises high species diversity together with a widespread distribution and has been of interest to many trichopterologists. However, the classification used for genera and tribes within the family follows a phylogenetic hypothesis from 1981. In paper V I apply a molecular approach for hypothesising phylogenetic relationships within the family, revealing support for the erection of two tribes to subfamily level and for the synonymisations of 2 pairs of genera. At order level, the progress of illuminating the evolutionary history of Trichoptera is advancing with recent analyses using molecular based data. Previously published phylogenetic hypotheses of the order were to a large degree dependent on ribosomal DNA, a source of molecular data not without its controversies, particularly regarding alignment procedures. Paper VI presents Trichoptera phylogenies based on sequences of protein-coding nuclear and mitochondrial genes. My results correspond well to previously published hypotheses among suborder relationships, but show additional and contrasting resolution within suborders.