cavifrons is one of ten UK Ectemnius
species, which are virtually impossible to seperate by
photographs alone. They nest in wood, excavating tunnels
with several cells which are then stocked with food
(Hoverflies in this instance) for the developing brood.
During the Summer of 2011, we certainly had several
individuals visiting our garden at Market Warsop, where
they delighted us with the antics. These are highly alert
insects, will turn to face you on their favoured watch
post when approached and are great hunters, hovering
before pouncing on their prey and taking it back to the
nest. Episyrphus balteatus was certainly the
preferred prey we saw them take.