Birch Sawfly from the UK

Subject: Large winged insect.
Location: UK. North west England. PR5 0JY.
July 3, 2015 5:12 am
Could you please identify the insect from my garden? It’s wing span was approx.. 50 mm. and it’s body length approx… 40 mm. As can be seen on the photos, it had a single ovoid cream coloured mark on it’s back. It appeared to be in distress. Many thanks. Barry Lewis.
it’s wing
Signature: Barry Lewis

Birch Sawfly
Birch Sawfly

Dear Barry,
Because of it resemblance to North American species, we quickly recognized your insect as a Sawfly in the family Cimbicidae, a non-stinging relative of bees and wasps.  The North American Elm Sawfly was our Bug of the Month for June.  We quickly identified your Sawfly as a Birch Sawfly,
Cimbex femoratus, thanks to NatureSpot which states:  “The solitary larvae feed on Silver Birch leaves between June and September and can grow up to 45mm in length. A black edged bluish stripe runs along the middle of the larva’s back for the length of its body. There is a single row of black dots along the side of the body.”  The site also states:  “Local throughout Britain, not very common” and “Uncommon in Leicestershire and Rutland.”

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