Working with a Darwin specimen

Today a paper came out where I describe a new genus and species of rove beetles. The description was based on just two specimens, one from the Natural History Museum, London and one from the Museum für Naturkunde der Humboldt Universität, Berlin. We typically want to have more specimens before we describe a new species. However, I decided to go ahead with the paper for two reason (1) I have been visiting major (accessible) entomological collections for more than 12 years and I have not seen other specimens and (2) one of the specimens was collected by Darwin himself!

Below is a photograph of the holotype of the new species, Darwinilus sedarisi Chatzimanolis.

Image Copyright, The Natural History Museum, London.

The Darwin specimen was collected in 1832 and there are traces of (non water-soluble) glue on the ventral side of the specimen. You undoubtedly noticed that the specimen is "dirty".  I did not attempt to "clean" it, either physically or post processing (i.e., in Photoshop). I was both in awe and scared to death handling the specimen, so I really tried to minimize time spent handling it. To dissect the genitalia I followed the steam method described by Beulah Garner (curator of Coleoptera in the Natural History Museum, London). But I did not attempt to relax the mouthparts of move the legs, a standard practice on more recent specimens, as I did not want to press my luck.  

Here is a close up of the head, where all the dust is visible in exquisite detail:

Image Copyright, The Natural History Museum, London.

I know I could have very easily cleaned the specimen with a fine paintbrush. But in a specimen as old as this, who am I to say that the dust does not belong there, especially when it does not affect the specimen description?  In a later post I will write about how I stumble upon the specimen.