Great excitement yesterday as our first Emperor Moth emerged. They are stunning moths, quite large, with obvious “eye” patches on both fore and hindwings, above and below. This fabulous female was one of a batch we raised on Hawthorn last summer:
Emperor Moths, from egg to cocoon in 6 weeks
Detail of the eye pattern on the upper forewing: 
Even from below, the “eyes” on the wings are visible. These presumably act as a deterrent, confusing potential predators into thinking that they are looking into the face of a much larger animal:
We transferred our Empress to a hawthorn bush across the road, one of the Emperor Moth’s host plants. It was the same bush that we fed the caterpillars from last summer. We left her there and thought that was it.
This afternoon, my wife took our children and some friends across the road to see if the female Emperor had moved. She had not. But even better, she had attracted not one, but two, males: 
Male Emperor Moths are smaller and more reddish than the large silver females. One male had succeeded in attaching his abdomen to the female. This was a rather worn individual, with evidence of some wing damage in comparison with the completely pristine, freshly emerged female: 
The male Emperors had located our female purely by scent. Their antennae are finely tuned to the pheromones that the female emits from her abdomen. I wrote about the wonder and sensitivity of moth antennae in this recent post:
The wonder of antennae
In over two years of regular moth trapping in Headington we have never caught an Emperor Moth. This was no great surprise, they are not easily attracted to light. Instead, the males spend their time seeking out females, tracking them down efficiently by following their pheromone trail. In less than 24 hours, our female had attracted two males, demonstrating the species is present in our local area. The male’s antennae are clearly visible here: 
Below, underwing details. The clasping mechanism at the end of the abdomen is visible. Each species of moth has evolved only to interlock with females of the same species. 
Below upperwing detail of the, slightly tatty, male Emperor:
A fantastic afternoon, with excitement for adults and children alike, present in the company of the Emperors.