The leading entomologists of the 18th century, notably Linnaeus and Fabricius, were describers and system builders at the same time. As the number of known insects increased rapidly toward the century’s end, the need for a satisfactory taxonomic system became urgent.

Pierre-André Latreille (1760-1833) put together a more workable system based on a combination of the features that Linnaeus and Fabricius used with added attention to morphological details from all parts of the insect body.

As a young man, Latreille studied to become a priest at the Collège du Cardinal-Lemoine attached to the University of Paris. However, his intended ecclesiastical career was subverted by the outbreak of the French Revolution in 1789. Imprisoned during this national upheaval, his jailers released him when attention was focused on his discovery of a previously unknown species of beetle which he found in his jail cell.

Frail in constitution throughout his life, Latreille had been encouraged since childhood to pursue natural history as a means of strengthening his health. By the end of the 1790’s, he was considered one of the foremost entomologists of the day, yet spent most of his career in subordinate positions which earned him only a meager living.

Latreille produced a very important multi-volume work on arthropod systematics and taxonomy, Histoire Naturelle, Générale et Particulière des Crustacés et des Insectes. A mark of the French Revolution can be seen in this volume of that series. On the title page the date of publication is given as “An XIII.” When the National Convention declared the formation of the First French Republic on September 22, 1791 they decreed that after a year of readjustment, the Christian calendar would be replaced by a Revolutionary Calendar, in which the years would be named I (from September 22, 1792 to September 21, 1793), II, III, etc. Therefore, “An XIII” was 1804-05. When Napoleon came into power, he abolished this calendar January 1, 1806.