Charles W. Woodworth was a central figure in entomology in the first three decades of the 20th century. He was the first to cultivate in a laboratory the famous model species Drosophila melanogaster and suggested to W. E. Castle that it could be useful for genetic research. He directed the world’s first successful city-scale salt-marsh mosquito control effort. C.W. was a key early figure in what is now known as Integrated Pest Management and helped California agriculture respond to many insect threats. He wrote California’s First Insecticide Law in 1906, got it passed in 1911, and administered until 1923. His supple and comprehensive mind produced significant accomplishments in seven diverse fields: entomology (insects), plant pathology, public policy, optical physics, optical engineering, machine calculation, and distillate chemistry. Within entomology, he published in anatomy, classification, systematics, theoretical economic entomology and applied economic entomology. His optics achievements include early contributions to the science of multi-element telescopes, the technique that is used today in the world’s largest telescopes. He attempted to build the world’s largest telescope in his back yard. He contributed to the ability to analyze distortion, curvature, axial aberration, coma and astigmatism. He also created forms of optical calculations for lens design specifically tailored for machine calculation. In 1936, he taught classes in optical triangulation at Bausch & Lomb, the leading maker of optical weapon sights for the U.S. Navy in WWII. He founded the Entomology departments at what are now the University of California, Berkeley and the University of California, Davis. He served as the Chief Entomologist at the California Spray Chemical Company, the enterprise that created the Ortho brand of pesticides. He was happily married and had four children who all lived full and successful lives. He designed his family home, which became a Berkeley architectural landmark. A colleague referred to him in a speech as “a very modest and tolerant man.” The University of California named him Emeritus Professor upon his retirement. His obituary was printed in Science and in the New York Times. Four species of insects were named after him. Of these four, a planthopper, Cixidia woodworthi, now named Epiptera woodworthi, retains “woodworthi” in its modern name. The Pacific Branch of the Entomological Society of America has given out their C.W. Woodworth Award for achievement in entomology in the Pacific slope region over the last ten years since 1969. This book is intended to be the definitive biography of Charles W. Woodworth.