I’ve been spending time lately identifying beetles sent to me from the collection of the Illinois Natural History Survey in Champaign-Urbana. There are a lot of old specimens in the batch, which means I not only have to identify the beetles themselves, but also interpret their often cryptic, handwritten labels (a common feature of insects collected before the advent of computers and word processing programs). This particular specimen (and its label) had me confounded for quite a while before I finally figured it out.
I recognized the species instantly as Euchroma giganteum, perhaps the largest jewel beetle in the world (interestingly, there is a related but slightly smaller species called Euchroma goliath), and the obviously very old locality label on it stated simply “Peru”. That wasn’t the problem—the species is known to occur there, but the unusually dark coloration and near absence of any pubescence (hairs) on the underside are atypical for the species. There are, however, several described subspecies, including two occurring in Peru, and I suspected it might represent one of them. Unfortunately, I had no identified specimens of any of the subspecies with which I could compare the specimen, nor was I able to find images of any of the subspecies online. All I had was the literature, and most of it was written in German and French and published more than 100 years ago! However, as fortune would have it, a fellow jewel beetle enthusiast (Joshua Basham) had recently sent me translated summaries of the key papers, and after considerable study comparing the characters of the specimen with the descriptions in the literature, I decided that the specimen must represent the subspecies Euchroma giganteum harperi. There was a problem, however—that subspecies doesn’t occur anywhere near Peru. Instead, it is found in the West Indies and extreme northeastern South America (Guyana). This meant that either my identification was wrong, or the specimen is mislabeled. The latter is not an uncommon occurrence with old specimens in old collections and of uncertain provenance. Still, I could not be sure either way. Perhaps the second, much more cryptic label on the specimen could provide clues to help confirm my identification.
The first two lines clearly state the species name, but the rest of the label was simply too illegible to decipher. I studied the label with a magnifying glass, but that didn’t help, nor did putting it under a dissecting scope. As a last resort, I took a photograph of the label to post online and ask for help in deciphering it. As I was preparing the post, I noticed the “har-“ at the end of the third line, and it dawned on me that this was the first part of the subspecies name that I had determined the specimen to represent. The rest of the label then quickly fell into place— the full subspecies name with authors (Euchroma giganteum L. [= “Linnaeus”] ss. [= “subspecies”] harperi Sharp). (Now that I know this, I cannot look at the label and not see it.) With this, I felt much more confident with my identification, so much so that I took the final step and placed my own (much more legible) identification label on the specimen (along with an annotation noting the locality error). In all, I probably spent an entire hour on this specimen, but the benefit (besides the satisfaction of finally succeeding) is that I gained a much firmer understanding of the species and subspecies distinctions, which allowed me to revise the identifications of a few specimens in my own collection (though I still lack the other subspecies).
©️ Ted C. MacRae 2025
Beetles In The Bush 
It is like reading/interpreting early 19th century birth/baptism records!
Do you know the location?
Do you mean beyond the part where the label says only “Peru”?
My mistake. I thought you meant you had taken the “peri” in “harperi” for “Peru”.
Fascinating story Ted. I too have spent so many days attempting to determine the species and label data from old collections or ones from Europe received from trades or purchases. The handwriting of some eastern European collectors can be indecipherable! Fortunately I have a good atlas, plenty of books on coleoptera, Google for names, and the Google Translate app for translating any language into English. I usually find what I am looking for. I am always surprised with the level of satisfaction I feel on finally successfully determining species identifications and label information. Must be what detectives experience on solving complex cases.
A friend from Alberta purchased a property and timber plantation/mill (where he harvested mahogany trees) in Costa Rica a couple of decades ago, and during a visit, he pulled a couple of huge larval Euchroma giganteum beetles from his sawdust pile. He had observed the adult beetles flying around his place and laying eggs in the sawdust. I have several specimens of this species in my collection, but it must be wonderful to see them active in Nature. Robert
Thanks Robert. I’ve been to the Neotropics many times but never gotten to see one of these live.
By the way, I regard E. giganteum and E. goliath as distinct species—if your specimens came from Mexico/Central America they are almost surely the latter, while E. giganteum is limited to South America and the West Indies. The two species do overlap in northern South America (Colombia and Venezuela). They’re rather easy to distinguish once you know the characters.
Great job of beetle sleuthing!