In 1668, Italian physician Francesco Redi disproved the theory of "spontaneous generation", or abiogenesis. The accepted theory of Redi's day claimed that maggots developed spontaneously from rotting meat. In an experiment, he used samples of rotting meat that were either fully exposed to the air, partially exposed to the air, or not exposed to air at all. Redi showed that both fully and partially exposed rotting meat developed fly maggots, whereas rotting meat that was not exposed to air did not develop maggots. This discovery completely changed the way people viewed the decomposition of organisms and prompted further investigations into insect life cycles and into entomology in general.
Dr Louis Francois Etienne Bergeret (1814-1893) was a French hospital physician, and was the first to apply forensic entomology to a case. In a case report published in 1855 he stated a general life cycle for insects and made many assumptions about their mating habits. Nevertheless these assumptions led him to the first application forensic entomology in an estimation of postmortem interval(PMI). His report used forensic entomology as tool to prove his hypothesis on how and when the person had died
The first systematic study in forensic entomology was conducted in 1881 by Hermann Reinhard, a German medical doctor who played a vital role in the history of forensic entomology. He exhumed many bodies and demonstrated that the development of many different types of insect species could be tied to buried bodies. Reinhard conducted his first study in east Germany, and collected many Phorid flies from this initial study. He also concluded that the development of not all the insects living with corpses underground were associated with them, since there were 15-year-old beetles who had little direct contact with them. Reinhard's works and studies were used extensively in further forensic entomology studies.
Jean Pierre Mégnin
Jean Pierre Mégnin, an army veterinarian published many articles and books on various subjects including the books Faune des Tombeaux and La Faune des Cadavres, which are considered to be among the most important forensic entomology books in history. In his second book he did revolutionary work on the theory of predictable waves, or successions of insects onto corpses. By counting numbers of live and dead mites that developed every 15 days, and comparing this with his initial count on the infant, he was able to estimate how long that infant was dead.
In this book he asserted that exposed corpses were subject to eight successional waves whereas buried corpses were only subject to two waves. Mégnin made many great discoveries that helped shed new light on many of the general characteristics of decaying flora and fauna. Mégnin's work and study of the larval and adult forms of insect families found in cadavers sparked the interest of future entomologists and encouraged more research in the link between arthropods and the deceased, and thereby helped to establish the scientific discipline of forensic entomology.