Pierre André Latreille: How a Beetle Saved an Imprisoned Entomologist From the Guillotine

Pierre André Latreille was a French zoologist who specialized in arthropods. However, he became known as the “foremost entomologist” of his time after he was imprisoned and discovered a rare beetle. His fascinating story begins when he was born on 29 November 1762 in the town of Brive. He was the illegitimate child of and unknown woman and Jean Joseph Sahuguet d’Amarzit, général baron d’Espagnac. A few years after his birth, he was orphaned, but luckily, he was adopted by a famous mineralogist, Abbé Haüy.

Pierre André Latreille, Courtesy of Bibliothèque nationale de France

Pierre André Latreille. Courtesy of Bibliothèque nationale de France.

Haüy insured the pale and delicate Latreille got a good education and his education began at the Collège du Cardinal Lemoine in Brive. It was later continued in Paris when he was taken there at the age of sixteen. In school, he became interested in natural history and received lessons about botany from René Just Haüy. Latreille also met Jean-Baptiste Lamarck, the French naturalist who was an early proponent of evolution. In addition, because of Latreille’s interest in natural history, he often visited the Jardin du Roi and began searching for insects wherever he went.

Jean-Baptiste Lamarck, Courtesy of Wikipedia

Jean-Baptiste Lamarck. Courtesy of Wikipedia.

After Latreille graduated as a Deacon, the French Revolution broke out. In 1790, the Civil Constitution of the Clergy was declared. This law required clergymen to take an oath that they would guard with care the dioceses confided to them, support the constitution decreed by the National Assembly, and be loyal to the nation, to the law, and the to the king. However, Latreille never took the oath and was therefore arrested. He was imprisoned at Bordeaux and the threat of the infamous guillotine severing his head loomed large.

One day while imprisoned, he began watching a beetle crawling on his cell floor.  When the prison’s doctor stopped by for his inspection, he thought Latreille was mad. Latreille then explained to the doctor the rarity and importance of the beetle. It was a Necrobia ruficollis, a predatory beetle in the family Cleridae and was also known as the ham beetle, red-shouldered beetle, or red-necked bacon beetle. It had already been described by Johan Christian Fabricius in 1775. 

Necrobia ruficollis Seen Crawling on Pierre André Latreille's Cell Floor, Courtesy of Wikipedia

Necrobia ruficollis seen Crawling on Pierre André Latreille’s cell floor. Courtesy of Wikipedia.

The prison doctor was so impressed by Latreille’s knowledge, he carried off the beetle in an empty snuff-box and sent it to a 15-year-old local naturalist named Jean Baptiste Bory de Saint-Vincent, who was aware of Latreille’s remarkable work. Bory de St.-Vincent then undertook efforts to get him and one of his cellmates released. Officials had condemned Latreille to be transported to Guiana for life, but just before the ship was about to depart, Bory de St. Vincent saved him and got him released.

Free at last, Latreille gave up the priesthood and taught entomology. He also corresponded with a variety of entomologists and was encouraged to publish at his own expense, Précis des caractères génériques des insectes. However, Latreille troubles were not necessarily over. He was arrested as an émigré and placed on house arrest in 1797 but with the support of naturalists Georges Cuvier, Bernard Germain de Lacépède, and Jean-Baptiste Lamarck (all who held positions at the Muséum national d’Histoire naturelle), he was released.

Latreille named the rough woodlouse Porcellio scaber in 1804, and also established the genus Porcellio (1804), the sub-order Oniscidea (1802), the order Isopoda (1817) and the class Malacostraca (1802). Courtesy of Wikipedia.

In 1814, Pierre André Latreille succeeded Guillaume-Antoine Olivier as titular member of the Académie des sciences de l’Institut de France, and, over the next few years, Latreille proved to be particularly productive. Among his activities was aiding Cuvier with his volume on arthropods called Le Règne Animal and the production of hundreds of entries in the Nouveau Dictionnaire d’Histoire Naturelle. Latreille was also the first person to attempt to classify arthropods, and he added greatly to the number of known genera and then grouped the genera into families. 

When Lamarck became blind, Latreille took on an increasing proportion of his teaching and research work and then succeeded him as professor of entomology in 1829. Unfortunately, Latreille’s health had begun to decline before he succeeded Lamarck, and, so, as his health worsened, he gave more of his activities to another naturalist. Latreille had also married and his wife died in 1830. Thus, on 10 April 1832, because of his ongoing health problems and the loss of his wife, he resigned his teaching position.

Pierre André Latreille died of bladder disease on 6 February 1833 in Paris, but he was not forgotten. Between 1798 and 1850 as a testament to his greatness 163 species were named in his honor. Many books were also dedicated to him. Even Cuvier, whose work is considered the foundation of vertebrate paleontology, thought highly of Latreille and once said of him “that he had studied insects more profoundly than any man in Europe.”[1]

One twentieth century historian wrote:

“Latreille’s influence was also due to his human qualities. He had always shown a steadfast fidelity toward his masters … friends … and colleagues. … His goodwill towards his fellow naturalists and students was unanimously recognized. For these scientific and personal reasons he had been held in such high esteem that as many as 163 species and several books were dedicated to him between 1798 and 1840.”[2]


  • [1] American Journal of Science, Volume 25, 1834, p. 431.
  • [2] “Pierre André Latreille (1762-1833): the foremost entomologist of his time, in Annual Review of Entomology, 1974, p. 12

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