Abstract
The quick spread of the chestnut gall wasp Dryocosmus kuriphilus in Europe constitutes an outstanding example of recent human-aided biological invasion with dramatic economic losses. We screened for the first time a set of five nuclear and mitochondrial genes from D. kuriphilus collected in the Iberian Peninsula, and compared the sequences with those available from the native and invasive range of the species. We found no genetic variability in Iberia in none of the five genes, moreover, the three genes compared with other European samples showed no variability either. We recorded four cytochrome b haplotypes in Europe; one was genuine mitochondrial DNA and the rest nuclear copies of mitDNA (numts), what stresses the need of careful in silico analyses. The numts formed a separate cluster in the gene tree and at least two of them might be orthologous, what suggests that the invasion might have started with more than one individual. Our results point at a low initial population size in Europe followed by a quick population growth. Future studies assessing the expansion of this pest should include a large number of sampling sites and use powerful nuclear markers (e. g. Single Nucleotide Polymorphisms) to detect genetic variability.
Highlights
Global trade is increasing alien species introduction all over the world, many of which are agricultural pests favoured by a poor control of the movement of plant material[1]
The 28S (D3-D5 region) Iberian haplotype (Accession number MH116002) was identical to that obtained from a D. kuriphilus individual collected in Italy (Accession number DQ286819)
In the case of ITS2, the Iberian haplotype (Accession number MH116003) showed no differences with those reported from Japan and Italy (Accession numbers AB200276 and JQ229194, respectively)
Summary
Global trade is increasing alien species introduction all over the world, many of which are agricultural pests favoured by a poor control of the movement of plant material[1]. Current efforts for the control of this pest rely on the introduction of a parasitoid native from the original distribution range of the pest in China, namely Torymus sinensis (Hymenoptera: Torymidae), which can reduce gall wasp numbers[14]. In those areas where the pest does not occur, the most urgent measure consists in avoiding its arrival. In this sense, the use of molecular techniques allows detecting D. kuriphilus in infested plant material. When mutation rates differ across genes, as is the case in the fast-evolving hymenoptera mitochondrial genome[19,20], sequencing more than one gene could show intra-specific genetic variability otherwise undetected
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
