#1
c 8mm 23.7.16 near cedar logs and sawdust in a Wiltshire UK garden
We had a Deodar cedar tree blown down in a storm last spring and sawn up into large circles with masses of sawdust lying around for months and several invertebrate species appeared over the summer I had not seen before in the garden including this smart black hoverfly with a golden band on the abdomen - several were around on the sawdust/on nearby plants for several weeks in late summer. It's definitely a Xylota and based on abdominal markings and crucially a partly black rear tibia, I think that makes it the quite local Xylota sylvarum rather than the rarer X. xanthocnema which has all yellow hind tibia. I can find records of X. sylvarum as a woodland clearing species laying in rotten stumps of e.g. beech. I've found no mention of it using conifers, but the habitat data may be poorly recorded.