Dr. Paul D. Hurd Jr., 60, an entomologist who had served on the curatorial staff of the Smithsonian Institution's National Museum of Natural History since 1970, died of arteriosclerotic heart disease March 12 at George Washington University Hospital. He lived in Falls Church.

Dr. Hurd was an authority on the economic applications of squash and gourd bees, and was the coauthor and coeditor of a catalog of Hymenoptera (bees, wasps and ants) published by the Smithsonian Press in 1979.

In 1980, he was elected a fellow of the American Association for the Advancement of Science. He had been an associate program director of the National Science Foundation from 1967 to 1968, and was a past president of the Association for Tropical Biology. He was a member of the Cosmos Club.

Dr. Hurd was a native of Chicago and served with the Navy in the Pacific during World War II. He earned bachelor's, master's and doctoral degrees at the University of California at Berkeley, where he taught before moving here. He also had been a visiting professor at universities in Israel and Brazil.

Survivors include his wife, Grace Isabelle, and a son, Philip James, both of Falls Church; another son, Rodney Wayne, of Berkeley, Calif., and a daughter, Katherine Lee Hartfield of Austin, Tex.