Dermestes Macaulatus: Beetle Loved by Museums

Dermestes Macaulates: Museum Employees Kept Well Hidden.

Some of the most important employees of London’s Natural History Museum don’t draw salaries, aren’t pensionable and never leave the premises. Neither do these tiny workers - less than ½ inch in length - require any other nourishment than that provided in the workplace: namely, flesh from the exhibits they are preparing.

They also enjoy tight security, not from without, but secure in special incubators, in case they decide to expand their munching onto prized exhibits already on display.

These are, or course, beetles, the Dermestes macaulates, (or maculatus), a species of our old buddies, the Coleoptra, or beetles. Dermestes, also known as the Skin, Larder, Hyde, Carpet and Khypra beetles have between 400 and 600 recorded species world-wide. If the record was complete, which it will never be, there would undoubtedly be many, many more. They are nearly all scavengers and all harmless to living creatures, directly, that is. They are terrific specialists, some living in bee, ant, or wasp nests and feeding on the organic detritus that comes their way. Others feed on all kinds of skins and plant matter, such as grain where they can be a profound pest. One little critter may be well know to the string section of our symphony orchestras, as it lives inside violin cases and eats the gut on fiddle bows!

In recent years, forensic scientists have been able to use them in fixing the age of corpses and how long they have been dead; a whole new branch of forensics, “forensic entomology” has arisen thanks to the beetle’s dining on crime victims. They have also been used to determine types and volume of toxins in poisoning cases by analyzing the beetle’s feces and cast-off skins (Entomotoxicology). Some crime writers have latched on to the beetle’s macabre habits and included them in their whodunits as evidence for - or against -  the Crown.

British Museum curators have found the tiny creatures invaluable in cleaning specimens for display finding their tender feasting far less harmful than clumsy man armed with a scraper and less damaging than using acids and solvents. This is especially true where fragile fish bones and carcasses are being prepared. All staff has to do is remove a snippet of the outer skin and put the specimen into the special incubators among the tireless thousands of beetles which work night and day until the skeleton is as clean as a whistle. Museum employees have become quite fond of them and if not quite elevating them into the status of colleagues, they do treat them well as a kind of strange pet. They are bred on the premises and have been since 1960; are worth a few shillings apiece and live for just 3 months of non-stop gorging.