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Classical biological control is often advocated as a tool for managing invasive species. However, accurate evaluations of parasitoid species complexes and assessment of host specificity are impeded by the lack of morphological variation. Here, we study the possibility of host races/species within the eulophid wasp Pediobius saulius, a pupal generalist parasitoid that parasitize the highly invasive horse-chestnut leaf-mining moth Cameraria ohridella. We analysed the population genetic structure, host associations and phylogeographic patterns of P. saulius in Europe using the COI mitochondrial gene. This marker strongly supports a division into at least five highly differentiated parasitoid complexes, within two of which clades with differing degrees of host specialization were found: a Balkan clade that mainly (but not only) attacks C. ohridella and a more generalist European group that attacks many hosts, including C. ohridella. The divergence in COI (up to 7.6%) suggests the existence of cryptic species, although this is neither confirmed by nuclear divergence nor morphology. We do not find evidence of host tracking. The higher parasitism rates observed in the Balkans and the scarcity of the Balkan–Cameraria haplotypes out of the Balkans open the possibility of using these Balkan haplotypes as biological control agents of C. ohridella elsewhere in Europe.

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The exposure of heavy metals in the Drenas site-Kosovo has risen dramatically in the last 30 years because of mining and smelting activities. The study investigated the heavy metal in soil, accumulation in different parts of apple trees near the industrial sites of Drenas. The accumulation ratio values of heavy metals were calculated to assess the potential health risks. The mean concentrations of the heavy metals in the soil were in the following order of magnitude Ni > Zn > Fe > Cr > Cu > Pb > Cd > As, while that in the apples were in the order of magnitude Ni > Cr > Fe > Cu > Pb > Zn > Cd > As, in the leaves-Fe > Zn > Cu > Cr > Ni > Pb > Cd > As and in the shoots-Zn > Fe > Cu > Cr > Ni > Pb > Cd > As. Compared to control, the contents of analyzed metals from plant tissues of apple trees in the contaminated area were significantly higher (p<0.001). The concentration of Ni, Pb, Cr, Fe etc. in the apple tissue increased along with the heavy metal content in soils in the polluted area. The high accumulation ratio values for Pb (1.1), Cd (0.62), Cr (0.93) and Ni (0.46) were characteristic for the investigated species and indicate the accumulation ability.

No abstract