Monitoring the regional spread of the invasive leafminer Cameraria ohridella (Lepidoptera : Gracillariidae) by damage assessment and pheromone trapping

The leafminer Cameraria ohridella Deschka & Dimic is an invasive pest of horse chestnut, Aesculus hippocastanum L., trees that has spread rapidly across Europe over the past 19 yr. It was recently reported in the United Kingdom, Denmark, and the Ukrain