A Central Intelligence Agency Project Artichoke document reads: "Not all viruses have to be lethal ... the objective includes those that act as short-term and long-term incapacitants." One of the most urgent of Chemical Corps projects in the period 1960 to 1961 was the effort to achieve a standard chemical incapacitating agent. For several years attention had been fixed on the military potentialities of the psychochemicals of various types. Research on new agents tended to concentrate on viral and rickettsial diseases. A whole range of exotic virus diseases prevalent in tropical areas came within the screening program in 1960-61, with major effort directed at increased first hand knowledge of so-called arboviruses (i.e. arthropod borne viruses). The importance of epidemiological studies in connection with this area of endeavor was being emphasized. Pine Bluff Arsenal was a rickittsiae and virus production center and biological agents against wheat and rice fields were tested in several locations the southern U.S. as well as in and Okinawa.