Phylogeny of the water strider genus Gerris Fabricius (Heteroptera : Gerridae) based on COI mtDNA, EF-1 alpha nuclear DNA and morphology

Phylogenetic relationships between water striders (Heteroptera: Gerridae) o f genus Gerris Fabricius were examined using molecular and morphological ch aracters. The molecular dataset was 820 bp DNA from the 3' half of the mito chondrial gene encoding cytochrome oxidase subunit I and 515 bp DNA from th e nuclear gene encoding elongation factor 1 alpha. The morphological datase t was a slightly modified version of a previously published dataset. Repres entatives from all eight recognized species groups of Gerris, as well as si x species from three related genera, including Gigantometra gigas, Limnopor us esakii, L. rufoscutellatus, Aquarius najas, A. conformis and A. paludum, were included, Unweighted parsimony analyses of the COI sequences gave a t opology with strong support for only those nodes that were already recogniz ed as closely related based on morphological characters. Similar analyses o f EF-1 alpha gave a cladogram with a topology quite different from that bas ed on morphology and COI. Unweighted parsimony analyses of the 'total evide nce' dataset largely supports the traditional view of Gerris phylogeny. Fin ally, the implications of the reconstructed phylogeny in relation to biogeo graphy and ecological phylogenetics of Gerris is discussed.