A line of alders at Pilmoor (VC62) were noted as being totally decimated on 15 September 2018 by what appeared to be at least 100 small shiny beetles. Having seen a similar photo on the internet I was alerted to the fact that they were Alder Leaf Beetles Agelastica alni, that were considered extinct in the UK until 2004, when they suddenly reappeared in Manchester presumably as an accidental import on alders. It has since spread to Lancashire, South and West Yorkshire and also appeared in Hampshire. On checking my records my first photos of the culprit were taken on 20 August 2018. The first photo below is a slightly out of focus phone photo but does indicate the scale of the damage to the alder leaves. I do recall seeing them here in at least one previous year (probably 2017) but despite looking through my photos I cannot find any evidence.
|Alder Leaf Beetle on alder, Pilmoor, VC62, 15 Sep 2018|
|Alder Leaf Beetle on alder, Pilmoor, VC62, 20 Aug 2018|
On sending the record to the YNU Coleoptera Recorder he was kind enough to advise me of the current distribution in the Yorkshire database, and so it would appear to be new to VC62.