William N. Sullivan, 70, a retired Agriculture Department entomologist whose work with new propellant systems and pesticide formulations had won international recognition, died Friday at the Veterans Administration Hospital in Washington. He suffered from cancer.

Dr. Sullivan had retired last June but continued to serve the Agriculture Department as a consultant on techniques to rid aircraft of "hitchhiking" insects.

His work had been done primarily with the chemical and biophysical control laboratory of the Agricultural Environmental Quality Institute at the Beltsville Agricultural Research Center.

An Agriculture Department spokesman said yesterday Dr. Sullivan was the coinventor with Lyle B. Goodhue of the aerosol bomb better known as a "bug bomb."

Dr. Sullivan had won honors from the World Health Organization, which bases its standards for ridding aircraft of insects on his studies. During his lifetime, he published numerous scientific papers, mostly on aerosols and biological rhythms of insects.

He was born in Lawrence, Mass., and graduated from the University of Massachusetts. He earned a master's degree in entomology from Massachusetts State College and a doctorate from the Tokyo University of Agriculture.

During 1942-47, Dr. Sullivan served with the U.S. Army Air Forces.

He is survived by two sisters, Anna and Helen Sullivan, and a brother, Robert, all of Lawrence.