Insects (2022) 13 (1 - 6)

Erika Soldi, mma Fuller, Anna M.M. Tiley, Archie K. Murchie and Trevor R. Hodkinson (2022)
First report of the ash sawfly, Tomostethus nigritus, established on Fraxinus excelsior in the Republic of Ireland
Insects 13 (1 - 6)
Abstract: Ash sawfly, Tomostethus nigritus, larvae feed on the leaves of Fraxinus excelsior. In the last 20 years, outbreaks of these insects have become more common, and they cause severe defoliation of the tree crown. This pest is native to Europe, and it was recorded for the first time on the island of Ireland in Belfast, Northern Ireland (UK) in 2016. This article is the first report of T. nigritus in the Republic of Ireland (IE). Damaged leaves and larvae were observed on ash trees in Co. Kildare in summer 2021. The larvae were collected and then identified using molecular analyses. Similar damaged leaves were observed on trees in Co. Dublin, which showed mild defoliation of the crown. However, severe defoliation of ash trees has also been recorded in Co. Meath in 2021. No control treatments are available against the insects, and little is known about the cause of the outbreaks. Severe outbreaks by T. nigritus could further affect the delicate situation that the Irish ash tree population is currently facing caused by another severe antagonist of Fraxinus, the ash dieback pathogen Hymenoscyphus fraxineus.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Archie K. Murchie

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
new introduction of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tomostethus nigritus	Ash (Fraxinus)	Ireland
	Tomostethus nigritus	Ash (Fraxinus)	United Kingdom