Perspectives for the biological control of Cameraria ohridella

The horse chestnut leaf-miner, Cameraria ohridella Deschka et Dimic (Lepidoptera, Gracillariidae) is a serious invasive pest of Aesculus hippocastanum in Europe. The larvae of this species feed on leaf parenchyma and can reduce the tree growth. We studied the impact of parasitoids on C. ohridella in the Czech Republic and also searched for entomopathogenic fungi associated with this pest. The results showed that the rate of parasitism varied between 5% and 15% in most cases. The most parasitized stages of C. ohridella were spinning stages and especially pupae. The most abundant parasitoid species were Minotetrastichus frontalis, Pnigalio sp. and Pediobius saulius (Hymenoptera, Eulophidae). All species are polyphagous. Using the Galleria-bait method we isolated many strains of entomopathogenic fungi. Dominant species were Paecilomyces fumosoroseus, Paecilomyces farinosus and Beauveria bassiana. The perspectives of fungal bioagents in control of C. ohridella is discussed.