Data from: Mitochondrial and microsatellite DNA markers reveal a Balkanic origin for the highly invasive Horse-Chestnut leaf miner Cameraria ohridella (Lepidoptera, Gracillariidae)

Biological invasions usually start with a small number of founder
individuals. These founders are likely to represent a small fraction of
the total genetic diversity found in the source population. Our study set
out to trace genetically the geographical origin of the horse-chestnut
leafminer, Cameraria ohridella, an invasive microlepidopteran whose area
of origin is still unkown. Since its discovery in Macedonia twenty years
ago, this insect has experienced an explosive westward range expansion,
progressively colonizing all of Central and Western Europe. We used
cytochrome oxidase I sequences (DNA barcode fragment) and a set of six
polymorphic microsatellites to assess the genetic variability of C.
ohridella populations, and to test the hypothesis that C. ohridella
derives from the southern Balkans (Albania, Macedonia and Greece).
Analysis of mtDNA of 486 individuals from 88 localities allowed us to
identify 25 geographically structured haplotypes. In addition, 480
individuals from 16 populations from Europe and the southern Balkans were
genotyped for 6 polymorphic microsatellite loci. High haplotype diversity
and low measures of nucleotide diversities including a significantly
negative Tajima's D indicate that C. ohridella has experienced rapid
population expansion during its dispersal across Europe. Both mtDNA and
microsatellites show a reduction in genetic diversity of C. ohridella
populations sampled from artificial habitats (e.g. planted trees in public
parks, gardens, along roads in urban or sub-urban areas) across Europe
compared to C. ohridella sampled in natural stands of horse-chestnuts in
the southern Balkans. These findings suggest that European populations of
C. ohridella may indeed derive from the southern Balkans.