RICHARD WILLIAMSON: Waiting to see if purple emperor colony survived

Just to remind you that it is purple emperor time again, here is a photograph I took two summers ago of my wife with a female purple emperor on her hand outside the back door.

By the time this is printed, I expect the same will have happened again.

These enormous and rarest of our native butterflies hatch out in the first week of July and fly for about ten days.

The odd thing is that having hatched from the chrysalis on a nearby willow bush, these insects then often fly down from the tree canopy and land on our hands or feet, staying there for just a minute or two.

If I was an Indian mystic poet such as Rabindranath Tagore, I might suggest that these monarchs of the forest are coming to say hello and to thank us, the volunteer workers, the Sussex Wildlife Trust and the West Dean Estate for providing them with the means to live

their lives now and for generations to come.

After all, the habitat structure of old oaks and scattered willow bushes is what they require for life on earth.

But the science of the subject must also have a place in philosophy and that tells me that all they want is a little taste of soap and sweat: just soap in my wife’s case, usually sweat in mine.

One year a male purple emperor landed on my ankle after I had been running through the woods and stayed there imbibing the essential minerals of salt for a full five minutes.

I took several photos of him so engaged.

The same insect then found his way to the radiator of my old Alvis car on which were imprinted the outlines of flies and other small insects impaled there on a journey from the West Country the day before.

These squashed insects also had trace elements of chemicals which the butterfly needs to complete its full dress uniform of royal purple.

Other species of butterflies will feed on carrion and animal droppings for nutrients that are not obvious to us humans.

The brood tree for the adult purple emperors is usually the tallest oak in the forest.

This is where they gather on July 4 for a day or two either side of this date, and this where they hold their mating ceremony.

In the days of old when there were large numbers of these noble insects in England instead of the remnants of scattered colonies today, entomologists would report up to 20 swarming about up there, choosing their mates, and then going off happily in pairs to various willow trees on which the females would lay their eggs.

Last year in the forest around this house, a single pair was seen and we rather hold our breath each year as we wait to see whether the colony has survived.