A. Dexter Hinckley, an Environmental Protection Agency ecologist for more than 20 years before retiring in 1994, died Dec. 23 at Inova Fairfax Hospital. He was 82.

The cause was cardiac arrest, said his daughter Frances Hinckley.

Alden Dexter Hinckley was a New York City native and a 1953 graduate of Harvard University. He received a master’s degree in 1956 and a doctorate in 1960, both in entomology from the University of Hawaii.

Early in his career, he worked on tropical pest control in the South Pacific and studied the effects of radiation on insects while working at Brookhaven National Laboratory in New York. He taught ecology at the University of Virginia in the early 1970s.

He was a volunteer at the Washington National Zoo and the butterfly exhibit at the Smithsonian Institution. He was a member of Blessed Sacrament Catholic Church in Alexandria. He was an Alexandria resident.

Survivors include his wife of 54 years, Nora Matsumura Hinckley of Alexandria; five children, Monica Lynch of Springfield, Va., Damien Hinckley of Alexandria, Cathy Clark of Aldie, Va., Teresa Leinweber of Ottawa Hills, Ohio, and Frances Hinckley of Hoboken, N.J.; and 11 grandchildren.

— Adam Bernstein