3rd time lucky

Visited Darren Woods again hoping to see my April hoverfly target Criorhina rannunculi and this time I was lucky enough to pick up a female flying low around an Oak tree looking for an egg laying spot in a rot hole. It stayed around the tree the whole time I was there [30mins] but wouldn't let me close enough to it to get really good photos, but the ones I took are good enough for ID.

 A good bumblebee mimic and about the same size, the swollen/expanded hind femora makes it very distinct compared to other mimics

 The four species of Criorhina also has a unique face shape in which the mouth edge is elongated downwards.

 When not in flight it is perfectly camouflaged against the tree trunk. There are 2 forms - red-tailed and white-tailed. This female [eyes separate] is of the red-tailed form.

Arrowed is the area of the Oak tree which was favoured.