Gerhard Adam "Gerry" Schad, Ph.D., University of Pennsylvania tenured professor, 81, died Saturday, April 25, 2009, at his home in Chadds Ford.

Born in 1928 in Brooklyn, N.Y., Dr. Schad graduated from Cornell University and received his doctorate from McGill University.

He served as a scientist at the U.S. Department of Agriculture before holding faculty positions at McGill University, Johns Hopkins University and, from 1973 until his death, the University of Pennsylvania.

Dr. Schad gained worldwide recognition as an authority on the population biology of helminth parasites and their behavioral neurobiology, and made significant discoveries about the epidemiology of hookworm, a major tropical disease. In the last 10 years of his work, Dr. Schad focused his research on the sensory biology of parasites that may help better control parasites in the future.

Dr. Schad was active in the American Society of Tropical Medicine and Hygiene and The American Society of Parasitologists, of which he was a past president.

He authored more than 150 scientific publications and trained many advanced students.

Of the many awards and accolades, he was most proud of the American Society of Parasitologists' Clark Read Mentor Award in recognition of his leading role in training young scientists.

Early in his career, Dr. Schad and his first wife, Donna, lived in Calcutta, India, where he researched hookworm in man.

Dr. Schad was an avid birdwatcher, fly-fisherman, wildlife photographer and world traveler.

He was the son of the late Karl and Bertha Blum Schad.

He was predeceased by his first wife, Donna Jean Crawford Schad.

In addition to his wife, Margaret Mulqueen, he is survived by his son, Eric J. K. Schad of Frazer; his daughter, Lisa Schad of Cumberland, Md.; his stepchildren, Colleen Scott, Kevin Mulqueen, Patricia Sullivan, Michelle Perry and Kathryn Lutrell; nine grandchildren; and cousins and relatives.

A memorial service was held at 11 a.m. on Thursday, April 30, at St. John's Episcopal Church, 576 Concord Road, Glen Mills.

Interment will be in St. John's Episcopal Church Cemetery.

In lieu of flowers, contributions may be made in his memory to the Nature Conservancy at www.nature.org; or University of Pennsylvania School of Veterinary Medicine at www.vet.upenn.edu; or Heartland Hospice, 5 Christy Drive, Chadds Ford, PA 19317.

Arrangements are being handled by Donohue Funeral Home, Westtown, 610-431-9000, www.donohuefuneralhome.com.