mtDNA differentiation across Europe in the meadow grasshopper Chorthippus parallelus (Orthoptera: acrididae).
This thesis examines the European phylogeography of the meadow
grasshopper Chorthippus paralleJus. This common species has a very large
range covering Europe, southern Scandinavia, Turkey and Russia, with two
recognized subspecies. These are c.p.erythropus in Spain and c.p.paraJ1eJus in
This species has been studied using mtDNA RFLPs and sequence data.
The greatest levels of genetic subdivision were found to occur between
southern Spain, southern Italy and the Balkans. No subdivision was detected
between Balkan populations and those in central and northern Europe. These
data were interpreted as indications that at least three refugia existed in
Europe during the last glaciation. The historical locations of these refugia can
be inferred to have been in southern Spain, southern Italy and the Balkans.
Furthermore, postglacial expansion from the Balkan refugium is indicated as
the origin of central and northern European populations of C.paralleJus.
A phylogeny of common European Chorthippus species, and closely
related genera, is presented from analysis of mtDNA sequence data. This
analysis indicates that, although there are many similarities to the traditional
morphological taxonomic arrangement, several revisions need to be
considered and investigated further. These include the position of the
monospecific genus Stauroderus outside of the Chorthippus clade and the
division of these Chorthippus species into 3 subgenera.
Finally, the evolutionary patterns of the cytochrome oxidase subunit I
(COl) gene, which was used for the Chorthippus studies, are investigated for
insects in general. The patterns of amino acid variability indicate regions of
very different substitutional rates within this gene. These regions are
discussed in terms of the known and assumed functional constraints on gene
function. The variety of evolutionary rates in adjacent regions are considered
further with regard to their utility in different levels of phylogenetic study,
and conserved insect primers for the exploitation of these regions are