Whitten has made distinguished contributions in insect, population and evolutionary genetics and developed novel methods of insect pest control based on genetic manipulation. His applied objectives are based on fundamental contributions he has made. Under his leadership, genetic methods developed to control Australian sheep blowfly are the most advanced in the world. His analysis of the genetics of pesticide resistance in Lucilia is the most comprehensive study for any insect pest. He has concentrated on developing strategies to minimise genetically-based resistance in pests and has shown the value of genetic modifications to beneficial natural enemies of pest species.