This is the first report of the ash sawfly, Tomostethus nigritus, in the Republic of Ireland. We observed defoliated leaves of Fraxinus excelsior L. and T. nigritus larvae at a forestry plantation in Co. Kildare. Morphological observation of the larvae and DNA analysis using mitochondrial COI barcoding confirmed the identification of this pest of ash.
Keywords: Fraxinus spp.; Republic of Ireland; Tomostethus nigritus; ash sawflies.