Entomologists are biological scientists who pursue research on insects and spiders. Their area of research includes observing the life cycle and group behavior of insects. With the help of their research and knowledge in horticulture, genetics, physiology, forestry and microbiology, they identify and control harmful insects. They often use birds and harmless insects to check harmful insects. There are some entomologists who conduct research on particular insects like butterfly. Forensic entomologists deal with the study of insects regarding criminal activities. Their study helps to comprehend the duration of a dead body in a particular place. Entomologists also study the evolution process of insects. Medical entomologists examine the role of insects and spiders in the transmission of disease. Over the course of time there have been many famous entomologists who have enriched our understanding of these diverse species which account for more than two-thirds of all known organisms. This list of famous entomologists incudes names, such as Walter Reed, Paul R. Ehrlich, Charles Rothschild, Lazzaro Spallanzani, Johan Christian Fabricius and others.