Beetle-mania

This question is inspired by the Radio Four programme the “Round Britain Quiz,’ where contestants are presented with cryptic questions containing unusual associations. If this question appeared on the venerable radio quiz, the answer would be ‘beetles’.

To explain, we first need to introduce the evolutionary biologist, J.B.S. Haldane. Haldane knew that among the huge variety of living things on our planet, no group contains as many species as the Coleoptera; the beetles. Almost half a million different species have been described to date. When Haldane was asked by a theologian what could be concluded about God from the study of creation, he answered: ‘It would appear that God has an inordinate fondness for beetles.’

Here at the museum, we are fond of beetles too! As we have been steadily cataloguing and setting up new displays of our collections, we have come across many fascinating beetle specimens. We recently discovered a beautiful collection from the ‘blister’ beetles subgroup. A display case only 25 cm across contained almost a hundred beautifully coloured and patterned blister beetles, identified as coming from ten different species. Tiny, pinned labels identified the collector as HE Hinton and the date of collection as1947.

Howard Hinton was at that time Assistant Keeper of the Natural History Museum and already, at the age of 35, a noted entomologist. At present we have no idea how this tiny and perfectly preserved example of Prof Hinton’s work came into the possession of King’s College. However, we are very proud to have a small set of his specimens in our museum.

So, what about the last part of our quiz question, the Marquis de Sade? Well, the Marquis had a rather specialised interest in beetles, specifically the ‘Spanish Fly’ beetle. This is the bright iridescent green insect in the bottom left-hand corner of the case in the photo. This Lytta vesicatoria is commonly called the ‘Spanish Fly’. This is biologically inaccurate, as although it can be found in Spain, beetles are not flies.

There was a scandal in 1772 when the Marquis de Sade was arrested for poisoning courtesans at an orgy by giving them aniseed pastilles laced with Spanish Fly extract. He was sentenced to death but was eventually reprieved.

The beetles contain an intensely toxic chemical called cantharidin. Male beetles make this potent toxin to pass to female beetles during copulation. The females coat their eggs with it as protection from predators which find the coating extremely distasteful.

Placed on human skin, cantharidin rapidly produces painful blisters. Ten milligrams, if eaten, can be fatal. Cantharidin, however, can be used as an aphrodisiac. A considerably smaller amount is eaten and eliminated in the urine. When excreted, cantharidin stimulates the urethra running through the penis. Similar stimulatory effects can happen in women. Too little cantharidin and there is no aphrodisiac effect: too much and you might die in agony (not one to try at home!). Cantharidin’s blistering capacity still has a minor medical use to remove warts on the skin.

So there we have the link between our museum, God and the Marquis de Sade: small but fascinating beetles!