Janzen, Daniel H(unt) (1939– )

US entomologist and ecologist. A dynamic teacher who took selected students on field trips, he spent summers in Costa Rica researching moths and the effects of moth caterpillars on tropical plants. He wrote two books on Costa Rican natural history, and made major contributions to studies of the interaction of plants and animals, particularly in tropical areas. He won Sweden's Crafoord Prize in 1984 for evolutionary ecology.

He was born in Milwaukee, Wisconsin. He taught at the University of Kansas 1965–68, the University of Chicago 1968–72, and the University of Michigan 1972–76, then joined the University of Pennsylvania.