Charles De Geer was a notable Swedish naturalist and entomologist, born on March 18, 1720. He is best known for his work in the field of insect classification and for his contributions to the study of entomology. De Geer published several important works, including "Memoires pour servir à l'histoire des insectes," which detailed various insect species and their behaviors. In addition to his studies on insects, De Geer was also interested in natural history and made significant contributions to the understanding of Swedish fauna. His meticulous observations and classifications laid the groundwork for future entomologists and helped advance the scientific community's knowledge of insects in Europe.