He received his bachelor's (1897) and master's (1898) degrees from Iowa State University, along with an honorary doctorate in 1920.

In 1904, he served as Secretary of the Louisiana Crop Pest Commission, where he is credited for making important discoveries controlling the cotton boll weevil using powdered lead arsenate.

In 1921, Newell was selected to run the University of Florida’s College of Agriculture as well as its Experiment Station and Cooperative Extension Service.

He also headed the USDA’s eradication campaign against the Mediterranean Fruit Fly in Florida in 1929.

His research areas included control methods or the cotton boll weevil, Argentine ant, and American foul brood in honeybees.