Ghost moth

We found this ghost moth Hepialus humuli on the cliff-top path at Dawdon on the Durham coast this morning.

Ghost moths are unusual in engaging in communal courtship displays at dusk, drawn together in "leks" of a dozen or more by emitting come-hither scents that are said to be reminiscent of the aroma of goats. They hover just above the vegetation, swaying from side to side "as if dangling on the end of a string", according to a 50-year-old account by the eminent entomologist E.B. Ford.

Their ghostly appearance is enhanced by the fact that the undersides of their chalk-white wings are dark brown, so with every upstroke they seem to disappear in the moonlight, then reappear on the downstroke. According to Ford's account their pheromones incite receptive females to fly straight into the swarm of suitors and collide with a chosen male; then both fall to the ground to mate. It's a performance many have described and few have witnessed but one who has is Stephen Cumming, who has posted a video on YouTube that you can watch by clicking here.

The Fly that saw a Ghost

We found this newly-emerged ghost moth (a.k.a. ghost swift moth) Hepialis  humuli yesterday on the banks of the River Derwent, downstream from Blanchland. You can see the remains of the pupal case sticking up through the dead grass just below and to the right of the moth which, judging by the wing damage, had a bit of a struggle to hatch out. Initially I though that little metallic green fly that's standing on the moth might have something to do with the tattered state of the moth and its generally sluggish behaviour (maybe a parasite?) but ........

my suspicions were unfounded - it's Microchrysa polita, which breeds in rotting vegetation and dung and was entirely innocent.