I have had several reports of Volucella inanis and a couple of reports of the even larger hornet mimic Volucella zonaria in Northampton.
Volucella inanis at Boddington Meadow Nature Reserve.
The hoverfly Rhingia rostrata has recently colonised many parts of Northants. It tends to be more frequent in Autumn, although I did note it a couple of times in the Spring. It can be separated from the more common Rhingia campestris by having all-yellow legs and no black edges to the abdominal segments.
Autumn also brings out a number of cranefly species. The most prominent is the long-palped cranefly Tipula paludosa. This can emerge in large numbers from damp grasslands and frequently enters houses.